MoodleDocs - User contributions [en]

Development:Voice

2007-07-03T18:11:04Z

Davidberry: /* Current Focus */

{{Voice}}
{{Moodle 2.0}}

== Introduction ==
Moodle Voice is a project for embedding VoiceXML support into Moodle Core.

== Project Status ==
Analysis and Requirement Extraction Phase

== Current Focus ==

1. Describing the functionality to be made voice enabled within this project.

2. Add an experimental option called "VoiceXML" so only when this variable is checked, VoiceXML code is generated.

3. Create a php lib for VoiceXML to put all functionality of VoiceXML and to be used by the rest of the code.

4. Modify weblib.php and formslib.php intensively to use the VoiceXML lib and output VoiceXML code along with the html code if the VoiceXML variable is set.

5. Create a set of tests for every function and the integration of several functions to assure that the functionality is the expected one.

== Contacts ==
Student : [http://mayankjain20.googlepages.com Mayank Jain]

Mentor : [http://moodle.org/user/view.php?id=153093&course=1 David Horat]

== Suggestions ==
Please feel free to chip-in with your suggestions.

Moodle in education

2006-11-15T18:38:24Z

Davidberry: /* Blocks */

==Getting started==
If you are a new user and would like a list of all teacher documentation articles, please see [[:Category:Teacher]].

We are assuming that your site administrator has set up Moodle, you are a user with teacher privileges and the administrator has assigned you to a new, blank course. Don't forget, [http://demo.moodle.org/ demo.moodle.org] will let you play an hour at a time for free.

You will need to be [[Log in | logged into]] the course as a user who has been assigned [[Teacher|a role as a teacher]] (with editing rights) on that course to use most of the features below. We have some tips if you are having [[Can not log in | trouble logging in]].

Now onto the real details. You will find the [[Course homepage|course homepage]] is broken down into [[Course sections]]. A course is created by [[Adding resources and activities|adding resources and activities]]. When writing text in Moodle you have a range of [[Formatting options]] including using [[HTML editor|HTML in Moodle]]. There are different ways to enrol [[Students]] and assign them to one or more [[Groups]] in a course.

The example below shows a new course set up with topic sections, edit is on. There are a few of Moodle's many [[Blocks|blocks]] on the right and left sides of the topics, such as "Latest News" or "Administration". The teacher is all ready to add resources and activities or a few new blocks to their brand new course.
[[Image:Course edit on new 2.jpg|thumb|center|500px|Getting started image - a new course]]

==Editing course section==
[[Image:Turn_edit_on_Student_on_buttons.JPG]]<br>
To add or alter activities or resources a teacher will need to [[Turn editing on|turn editing on]] and off with a button on the course homepage. The student view button allows the teacher to get a general idea of what students will see. There is also an "editing on" link in the administration block. These buttons and links toggle between on and off. Here are some common editing icons, for more details about them [[Adding/editing_a_course#Editing_a_course|go to adding/editing a course]].

{| border="1" cellpadding="2" cellspacing="0"
!width="30"|Icon
!width="100"|Effect
!width="30"|Icon
!width="100"|Effect
!width="30"|Icon
!width="100"|Effect
!width="30"|Icon
!width="100"|Effect
|-
|[[Image:Edit.gif]]|| Edit text ||[[Image:Open.gif]] || Open ||[[Image:Delete.gif]] || Delete ||[[Image:Move.gif]] ||Move
|-
||[[Image:All.gif]] ||See all topics||[[Image:Closed.gif]] ||Close||[[Image:Right.gif]] || Indent ||[[Image:Movehere.gif]] || Move here
|-
||[[Image:One.gif]] || See one topic||[[Image:Help.gif]] ||Help || || ||[[Image:Marker.gif]] ||Make Current
|}
<br>

==Activity modules==

[[Image:Activity_dropdown.JPG|frame|right|Add an activity drop-down menu]]
There are a number of robust interactive learning [[Modules (teacher)|activity modules]] that you may [[Adding_resources_and_activities | add to your course]].

Communication and collaboration may take place using [[Chats]] and [[Forums]] for conversational activities and [[Choices]] to gain group feedback. Adding [[Wikis]] to your courses is an excellent way to allow students to work together on a project.

Work can be submitted by students and marked by teachers using [[Assignments]] or [[Workshops]]. The [[Quizzes]] offer several options for automatic scoring. You can even integrate your Hot Potato quizzes by adding a [[Hotpot]] activity.

[[Lessons]] and [[SCORM]] activities deliever content and offer ways of individualizing your presentation based upon a student's choices. Key words can be added to [[Glossaries]] by yourself or, if you allow it, your students.

[[Surveys]] and [[Database module|Databases]] are also very powerful additions to any course.

If all of that isn't enough for you then you can also [[Non-standard modules|add other modules]] that are not part of the official Moodle release!

==Resources==

[[Image:Resource_pulldown_menu.JPG|frame|left|Add a resource drop-down menu]]

Moodle supports a range of different [[Resources|resource types]] that allow you to include almost any kind of digital content into your courses. These can be added by using the [[Adding_resources_and_activities | add a resource]] dropdown box when editing is turned on.

A [[Text page]] is a simple page written using plain text. Text pages aren't pretty, but they're a good place to put some information or instructions. If you are after more options for your new page then you should be thinking about adding a [[Web page]] and making use of Moodle's WYSIWYG editor.

Of course the resource may already exist in electronic form so you may want to [[File or website link|link to an uploaded file or external website]] or simply display the complete contents of a [[Directory|directory]] in your course files and let your users pick the file themselves. If you have an [[IMS content package]] then this can be easily added to your course.

Use a [[Label|label]] to embed instructions or information in the course section.

==Blocks==
[[Image:Block_add_dropdown_list2.JPG |thumb|150px|right|Add Block drop-down menu]]
Each course homepage generally contains [[Blocks_%28teacher%29|blocks]] on the left and right with the centre column containing the course content. Blocks may be added, hidden, deleted, and moved up, down and left/right when editing is turned on. Examples of blocks can be see in the Getting Starting image above. "Latest News", "Blogs", "Upcoming Events", and "Recent Activity" are a few examples.

A wide range of [[Blocks_%28teacher%29#Block_types|over 16 different block types]] can provide additional information or functionality to the learner by the teacher. The standard blocks that come with Moodle are shown on the right. There are also many [[Non-standard blocks]] developed by Moodlers that an administrator can add to this list.

A teacher with editing rights will also have a course [[Administration_block|administration block]].

==General advice==

* Subscribe yourself to all of the [[forum]]s in your course so that you can keep in touch with your class activity.
* Encourage all of the students to fill out their [[Edit profile|user profile]] (including photos) and read them all - this will help provide some context to their later writings and help you to respond in ways that are tailored to their own needs.
* Keep notes to yourself in the private "Teacher's Forum" (under Administration). This is especially useful when team teaching.
* Use the [[Logs]] link (under Administration) to get access to complete, raw logs. In there you'll see a link to a popup window that updates every sixty seconds and shows the last hour of activity. This is useful to keep open on your desktop all day so you can feel in touch with what's going on in the course.
* Use the [[Recent_activity|Activity Reports]] (next to each name in the list of all people, or from any user profile page). These provide a great way to see what any particular person has been up to in the course.
* Respond quickly to students. Don't leave it for later - do it right away. Not only is it easy to become overwhelmed with the volume that can be generated, but it's a crucial part of building and maintaining a community feel in your course.
*Don't be afraid to experiment: feel free to poke around and change things. It's hard to break anything in a Moodle course, and even if you do it's usually easy to fix it.
* Use the [[Navigation bar|navigation bar]] at the top of each page - this should help remind you where you are and prevent getting lost

== See also ==
*[[Blogs]] - blogs in Moodle
*[[Teaching with Moodle]] - inspiring links
*[[Teaching do's and don'ts]] - hints
*[[Moodle manuals]] - a list of links to manuals and books
*[[Using Moodle book]] - a real book you can reprint!
*[[Teaching FAQ]] - common questions
*[http://moodle.tokem.fi/mod/book/view.php?id=5116&chapterid=256 Example of a course teaching checklist],
*One example of a site specific [[http://moodle.tokem.fi/mod/book/view.php?id=5116 Teacher's Moodle Manual]], done in Moodle with the book module
*[[Tips and tricks]]
*[[Student FAQ]] - students have questions about technology?

[[Category:Teacher]]
[[es:Documentación para Profesores]]
[[fr:Documentation enseignant]]
[[nl:Documentatie voor leraren]]
[[ru:Учителям]]
[[zh:教师文档]]
[[ja:教師ドキュメント]]

Development:Authentication API

2006-11-11T17:39:09Z

Davidberry: /* Authentication functions */

==Moodle authentication interface==

Authentication API This file describes Moodle interface functions to authentication modules. (This page is incomplete , I'll update it after I have phpdoc commented auth/ldap/lib.php)

Most of functions are from ldap-authentication module and are not implemented (yet?) on other modules. Please feel free to extend other modules to support same features or roll your own module.

Some of new function are still tested and are not documented here yet.

==Authentication functions==

Basic functions to authenticate users with external db

Mandatory:

auth_user_login ($username, $password)

Authenticate username, password with userdatabase.

Returns: true if the username and password work and false if they don't

Optional:

Following functions are optional , but if present they extends module usability with Moodle.

auth_get_userinfo($username)

Query other userinformation from database.

Returns:

User information in array ( name => value, .... or false in case of error Function honors update-flags so if
$CFG->auth_user_(atribute)_updatelocal
is present, it will return value anly if flag is true.

COURSE CREATING

auth_iscreator($username)

should user have rights to create courses

Returns: True if user has rights to create cources otherwise false

USER CREATION

Functions that enable user creation, activation and deactivation from moodle to external database

auth_user_exists ($username)

Checks if given username exists on external db

Returns: true if given usernname exist or false

auth_user_create ($userobject,$plainpass)

Creates new user to external db. User should be created in inactive stage until confirmed by email.

Returns: True on success otherwise false

auth_user_activate ($username)

activate new user after email-address is confirmed

Returns: True on success otherwise false

auth_user_disable ($username) {

deactivate user in external db.

Returns: True on success otherwise false

USER INFORMATION AND SYNCRONIZATION

auth_get_userlist ()

Get list of usernames in external db.

Returns: All usernames in array or false on error.

auth_get_users($filter='*')

Get ALL USEROBJECTS FROM EXTERNAL DB.

Returns: Array of all users as objects from external db

[[Category:Developer]]

Development:Authentication API

2006-11-11T17:36:04Z

Davidberry: /* Moodle authentication interface */

==Moodle authentication interface==

Authentication API This file describes Moodle interface functions to authentication modules. (This page is incomplete , I'll update it after I have phpdoc commented auth/ldap/lib.php)

Most of functions are from ldap-authentication module and are not implemented (yet?) on other modules. Please feel free to extend other modules to support same features or roll your own module.

Some of new function are still tested and are not documented here yet.

==Authentication functions==

Basic functions to authenticate users with external db

Mandatory:

auth_user_login ($username, $password)

Authenticate username, password with userdatabase.

Returns: true if the username and password work and false if they don't

Optional:

Following functions are optional , but if present they extends module asability with Moodle.

auth_get_userinfo($username)

Query other userinformation from database.

Returns:

Userinformation in array ( name => value, .... or false in case of error Function honors update-flags so if
$CFG->auth_user_(atribute)_updatelocal
is present, it will return value anly if flag is true.

COURSE CREATING

auth_iscreator($username)

should user have rights to create courses

Returns: True if user have rights to create cources otherwise false

USER CREATION

Functions that enable usercreation, activation and deactivation from moodle to external database

auth_user_exists ($username)

Checks if given username exist on external db

Returns: true if given usernname exist or false

auth_user_create ($userobject,$plainpass)

Creates new user to external db. User should be created in inactive stage until confirmed by email.

Returns: True on success otherwise false

auth_user_activate ($username)

activate new user after email-address is confirmed

Returns: True on success otherwise false

auth_user_disable ($username) {

deactivate user in external db.

Returns: True on success otherwise false

USER INFORMATION AND SYNCRONIZATION

auth_get_userlist ()

Get list of usernames in external db.

Returns: All usernames in array or false on error.

auth_get_users($filter='*')

Get ALL USEROBJECTS FROM EXTERNAL DB.

Returns: Array of all users as objects from external db

[[Category:Developer]]

Development:Roles

2006-09-16T16:29:12Z

Davidberry: /* External Examiner */

'''Roles and permissions''' will be in Moodle 1.7 and are available in the developer version of Moodle.

==Definitions==

A role is an identifier of the user's status in some context, for example, teacher, student and forum moderator are examples of roles.

A capability is a description of some particular Moodle feature. Capabilities are associated with roles. For example, ''mod/forum:replypost'' is a capability.

A permission is some value that is assigned for a capability for a particular role. For example, allow or prevent.

A context is a "space" in the Moodle, such as courses, activity modules, blocks etc.

==The existing system==

Currently in Moodle, we have a fixed set of roles i.e. primary admin, admins, course creators, editing teachers, non-editing teachers, students, and guests. For each role, the capability or actions that they can perform are fixed. For example, the role student allows the user to submit an assignment, but doesn't allow the user to browse/edit other users' work. By using this setup we limit ourselves to a rather rigid set of capabilities for each role. If we want, say a particular student or group to be able to mark assignments in a particular course, we can't do that without giving these users teacher privileges.

==The new roles and capability system==

{{Moodle 1.7}}The new system will allow authorized users to define an arbitrary number of roles (eg a teacher)

A role consists of a list of permissions for different possible actions within Moodle (eg delete discussions, add activities etc)

Roles can be applied to users in a context (eg assign Fred as a teacher in a particular course)

Here are the possible contexts, listed from the most general to the most specific.

#CONTEXT_SYSTEM -- the whole site
#CONTEXT_PERSONAL -- yourself
#CONTEXT_USER -- another user
#CONTEXT_COURSECAT -- a course category
#CONTEXT_COURSE -- a course
#CONTEXT_GROUP -- a group
#CONTEXT_MODULE -- an activity module
#CONTEXT_BLOCK -- a block

An authorized user will be able to assign an arbitrary number of roles to each user in any context.

Capabilities can have the following permissions:

#CAP_INHERIT
#CAP_ALLOW
#CAP_PREVENT
#CAP_PROHIBIT

If no permission is defined, then the capability permission is inherited from a context that is more general than the current context. If we define different permission values for the same capability in different contexts, we say that we are overriding the capability in the more specific context.

Since the capabilities in each role could be different, there could be conflict in capabilities. This is resolved by enforcing the rule that the capability defined for a more specific context will win, unless a prohibit is encountered in a less specific context.

For example, Mark has a student role at course level, which allows him to write into a wiki. But Mark also got assigned a Visitor role at a module context level (for a particular wiki) which prevents him from writing to the wiki (read only). Therefore, for this particular wiki, Mark will not be able to write to the wiki since the more specific context wins.

If we set a PROHIBIT on a capability, it means that the capability cannot be overridden and will ALWAYS have a permission of prevent (deny). Prohibit always wins. For example, Jeff has a naughty student role that prohibits him from postings in any forums (for the whole site), but he's also assigned a facilitator role in "Science forum" in the course Science and Math 101. Since prohibit always wins, Jeff is unable to post in "Science forum".

Allow and prevent will cancel each other out if set for the same capability at the same context level. If this happens, we refer to the previous context level to determine the permission for the capability.

This may sound more complex than it really is in practice. The upshot is that the system can be flexible enough to allow pretty much any combination of permissions.

==Upgrading from 1.6==

A smooth upgrade will be provided with 1.7. The existing roles (admin, teacher, student, etc), and the existing capabilities will be automatically retained. This is done by creating default roles at site/course levels, and assigning the current users to these roles accordingly. The default roles will have default capabilities associated with them, mirroring what we have in 1.6. With no modifications, Moodle will operate exactly the same before and after the upgrade.

===Teachers===

Users who were teachers will be assigned the default legacy teacher role (or non-editing teacher role) in all courses they were teacher.

===Students===

Users who were students will be assigned the default student role in all courses they were student.

===Guests===

There will still be a single guest user with no default role at site level. For each course that allows guest access, the guest role will be assigned to the guest user for that course context. The guest control for the course will be modified from three to two options (guests always need to enter enrolment key - on/off). This setting is checked as now to force guests to enter key.

==Capabilities==

This will be a comprehensive list of capabilities (it's not complete yet). It is important that capability names are unique.

===Core-level Capabilities===

Moodle core capability names start with 'moodle/'. The next word indicates what type of core capability it is, and the last word is the actual capability itself. The capabilities for the Moodle core are defined in lib/db/access.php

#moodle/legacy:guest - legacy capabilities are used to transition existing users to the new roles system during the upgrade to Moodle 1.7
#moodle/legacy:student
#moodle/legacy:teacher
#moodle/legacy:editingteacher
#moodle/legacy:coursecreator
#moodle/legacy:admin
#moodle/site:doanything - special capability, meant for admins, if is set, overrides all other capability settings
#moodle/site:config - applicable in admin/index.php and config.php (might break down later) : 1)admin/config.php 2)admin/configure.php 3)blocks/admin/block_admin.php load_content_for_site()
#moodle/site:readallmessages - reads all messages and history
#moodle/site:approvecourse - approves a pending course
#moodle/site:manageblocks - adding/removing/editing blocks (site, course contexts only for now) : 1)_add_edit_controls moodleblock.class.php
#moodle/site:backup - can create a course backup : 1)course/category.php 2)block_admin.php
#moodle/site:restore - can restore into this context : 1)course/category.php 2)block_admin.php
#moodle/site:import - can import other courses into this context : 1)block_admin.php
#moodle/site:accessallgroups - able to access all groups irrespective of what group the user is in
#moodle/site:accessdb - directly accessing db (phpmyadmin)
#moodle/site:viewfullnames - able to see fullnames of other users
#moodle/site:viewreports - able to view site/course reports
#moodle/site:trustcontent - ability to use trusttext feature and bypass cleaning in specific areas
#moodle/blog:view - read blogs
#moodle/blog:create - write new blog posts
#moodle/blog:manageofficialtags - create/delete official blog tags that others can use
#moodle/blog:managepersonaltags - create/delete official blog tags that others can use
#moodle/blog:manageentries - edit/delete all blog entries
#moodle/course:setcurrentsection - mark course section
#moodle/course:create - create courses : 1)course/edit.php 2)course/category.php 3)course/index.php
#moodle/course:delete - create courses : 1)course/category.php
#moodle/course:update - update course settings
#moodle/course:view - can use this to find participants
#moodle/course:viewparticipants - allows a user to view participant list
#moodle/course:viewscales - view scales (i.e. in a help window?) : 1)course/scales.php
#moodle/course:manageactivities - adding/removing/editing activities and resources (don't think it makes any sense to split these)
#moodle/course:managescales - add, delete, edit scales, move scales up and down : 1)blocks/block_admin.php 2)course/scales.php
#moodle/course:managegroups - managing groups, add, edit, delete : 1)course/groups.php 2)course/group.php
#moodle/course:managefiles - manage course files and folders
#moodle/course:managequestions - manage course questions
#moodle/course:reset - able to reset the course
#moodle/course:visibility - hide/show courses : 1)course/category.php
#moodle/course:viewhiddencourses - see hidden courses
#moodle/course:activityvisibility - hide/show activities within a course
#moodle/course:viewhiddenactivities - able to see activities that have been hidden
#moodle/course:sectionvisibility - hide/show sections
#moodle/course:viewhiddensections - view hidden sections
#moodle/course:viewcoursegrades - views all grades in course
#moodle/course:viewhiddenuserfields - view all hidden user fields
#moodle/course:managegrades - manages grades settings in course
#moodle/category:create - create category : 1)course/index.php
#moodle/category:delete - delete category : 1)course/index.php
#moodle/category:update - update category settings (sort and rename) this is currently an admin capability : 1)course/category.php
#moodle/category:visibility - hide/show categories : 1)course/index.php
#moodle/user:viewusergrades - view your own, or other user's grades (with specified context)
#moodle/user:create - create user : 1) user/edit.php
#moodle/user:delete - delete user : 1) admin/user.php
#moodle/user:update - update user settings : 1) user/edit.php
#moodle/user:viewdetails - view personally-identifying user details (e.g. name, photo).
#moodle/user:viewhiddendetails - view user details marked as "hidden"
#moodle/calendar:manageownentries - create/edit/delete
#moodle/calendar:manageentries - create/edit/delete
#moodle/role:assign - assign roles to users
#moodle/role:override - can override role capabilities (depending on context)
#moodle/role:manage - create/edit/delete roles, set capability permissions for each role
#moodle/role:unassignself - unassign yourself from your own roles
#moodle/role:viewhiddenassigns - view role assignments that have been marked as hidden
#moodle/question:import - imports questions (course level?) - Yes, question permissions currently need to be course-level.--[[User:Tim Hunt|Tim Hunt]]
#moodle/question:export - exports questions (course level?)
#moodle/question:managecateory - add/delete/edit question categories (course level?)
#moodle/question:manage - add/edit/delete a question (course level)

===User-level Capabilities===
# moodle/user:readuserposts -read individual user posts on profile page (parent?)
# moodle/user:readuserblogs -read individual user blogs on profile page (parent?)
# moodle/user:viewuseractivitiesreport-read individual activity report on profile page (parent?)
# moodle/user:editprofile - edit profile (normally used in CONTEXT_USERID and CONTEXT_SYSTEM)

===Module-level Capabilities===
The capabilities are cached into a database table when a module is installed or updated. Whenever the capability definitions are updated, the module version number should be bumped up so that the database table can be updated.

The naming convention for capabilities that are specific to modules and blocks is 'mod/mod_name:capability'. The part before the colon is the full path to the module in the Moodle code. The module capabilities are defined in mod/mod_name/db/access.php.

#Assignment
##mod/assignment:view- reading the assignment description
##mod/assignment:submit - turn assignment in
##mod/assignment:grade - grading, viewing of list of submitted assignments
#Chat
##mod/chat:chat - allows a user to participate in this chat
##mod/chat:readlog - allows a user to read past chat session logs
##mod/chat:deletelog - allows a user to delete past chat logs
#Choice
##mod/choice:choose - make a choice
##mod/choice:readresponses - read all responses
##mod/choice:deleteresponses - deletes all responses
##mod/choice:downloadresponses - download responses
#Database
##mod/data:readentry - reads other people's entry
##mod/data:writeentry - add / edit and delete (own) entries
##mod/data:managetemplates - add, delete, edit fields and templates
##mod/data:manageentries - edit/delete all entries
##mod/data:comment - comment
##mod/data:managecomments - edit/delete all comments
##mod/data:rate - rate an entry
##mod/data:approve - approves an entry
##mod/data:uploadentries - batch upload of entries
#Exercise
##mod/exercise:assess
#Forum
##mod/forum:viewforum
##mod/forum:viewdiscussion
##mod/forum:viewdiscussionsfromallgroups
##mod/forum:viewhiddentimedposts
##mod/forum:startdiscussion
##mod/forum:replypost
##mod/forum:viewrating
##mod/forum:viewanyrating
##mod/forum:rate
##mod/forum:createattachment
##mod/forum:deleteownpost
##mod/forum:deleteanypost
##mod/forum:splitdiscussions
##mod/forum:movediscussions
##mod/forum:editanypost
##mod/forum:viewqandawithoutposting
##mod/forum:viewsubscribers
##mod/forum:managesubscriptions
##mod/forum:throttlingapplies
#Glossary
##mod/glossary:view - read entries
##mod/glossary:write - add entries
##mod/glossary:manageentries - add, edit, delete entries
##mod/glossary:managecategories - create, delete, edit categories
##mod/glossary:comment - comment on an entry
##mod/glossary:managecomments - edit, delete comments
##mod/glossary:import - import glossaries
##mod/glossary:export - export glossaries
##mod/glossary:approve - approve glossaries
##mod/glossary:rate - rates glossary
##mod/glossary:viewrating - view ratings
#Hotpot
##mod/hotpot:attempt - attempt a hotpot
##mod/hotpot:viewreport - review and view reports
##mod/hotpot:grade - (grade? and) regrade
##mod/hotpot:deleteattempt - deletes attempts
#Label
##none
#Lams
##mod/lams:participate - original student
##mod/lams:manage - original teacher
#Lesson
##mod/lesson:view
##mod/lesson:edit - add and edit pages
##mod/lesson:manage - view student attempts
#Quiz
##mod/quiz:grade - comment, override grade, manual grade
##mod/quiz:preview - previews the quiz
##mod/quiz:viewreports - view quiz result reports
##mod/quiz:manage - add/delete/move (up or down) questions for a quiz
##mod/quiz:attempt - attempt the quiz--[[User:Tim Hunt|Tim Hunt]]
#Resource
##mod/resource:view
#Scorm
##mod/scorm:view
##mod/scorm:viewgrades
#Survey
##mod/survey:download - downloads survery result
##mod/survey:participate - participate/ do survey
##mod/survey:readresponses - read all user's responese
#Wiki
##mod/wiki:view - basic capability needed to view wiki content
##mod/wiki:participate - original student, meaning depends of type and course setting
##mod/wiki:manage - original teacher, manages assigned group; moodle/site:accessallgroups is needed to manage all groups
##(Waiting on new wiki)
#Workshop
##mod/workshop:view - basic capability needed to enter workshop
##mod/workshop:participate - original student, allows user to submit and assess
##mod/workshop:manage - original teacher, user can manage others
##(Waiting on new Workshop)

===Enrolment-level Capabilities===

The naming convention for capabilities that are specific to enrolment is 'enrol/enrol_name:capability'. The enrolment capabilities are defined in enrol/enrol_name/db/access.php.

#Authorize.net Payment Gateway
##enrol/authorize:managepayments - manage user payments, capture, void, refund, delete etc.

===Blocks===
#activity_modules
##None
#admin
#admin_2
#admin_bookmarks
#blog_menu
#blog_tags
#calendar_month
#calendar_upcoming
#course_list
#course_summary
#glossary_random
#html
#loancalc
#login
#messages
#news_items
#online_users
#participants
#quiz_results
#recent_activity
#rss_client
#search
#search_forums
#section_links
#site_main_menu
#social_activities

===Questions===
I am adding question categories here because they seem to have been forgotten in the whole scheme of things since having been removed from the quiz module itself. I've made a suggestion on how these could be handled in [http://www.moodle.org/bugs/bug.php?op=show&bugid=6118&pos= bug 6118].

See [http://moodle.org/mod/forum/discuss.php?d=51143 this forum thread] for a discussion about the current problems wth publishing question categories.[[User:Tim Hunt|Tim Hunt]] 18:50, 8 August 2006 (WST)

==Programming Interface==

Although the Roles system may look complicated at first glance, implementing it in Moodle code is fairly simple.

* You need to define each capability once, so that Moodle can upgrade existing roles to take advantage of it. You do this in an access.php inside the db folder of any module (eg see mod/forum/db/access.php). The array contains entries like this (note the descriptions for the legacy roles which provides forward compatibility):
'mod/forum:viewforum' => array(
'captype' => 'read',
'contextlevel' => CONTEXT_MODULE,
'legacy' => array(
'guest' => CAP_PREVENT,
'student' => CAP_ALLOW,
'teacher' => CAP_ALLOW,
'editingteacher' => CAP_ALLOW,
'coursecreator' => CAP_ALLOW,
'admin' => CAP_ALLOW
)
),
* To load/change these capabilities you need to bump the module version. There's no need to provide changes or differences as Moodle will scan the whole array and sort it out.
* On each page you need to find the context the user is working in, using the get_context_instance() function. For example, in the forum module:

$context = get_context_instance(CONTEXT_MODULE, $cm->id);
* Then, whenever you want to check that the current user has rights to do something, call has_capability() like this:
if (!has_capability('mod/forum:viewforum', $context)) {
print_error('nopermissiontoviewforum');
}
* If you just want to assert a capability and then finish with an error message if it's not met (as we did above), then a shorter way it to use require_capability() like this:

require_capability('mod/forum:viewforum', $context);

* Note that there are extra parameters you can specify to get a custom error message, otherwise users get an automated "No permissions" message that lists the permission they were missing.

As a result of the new Roles System, all calls to isadmin(), iscoursecreator, isteacheredit(), isteacher(), isstudent(), and isguest() will have to be replaced with calls to has_capability() or require_capability(). However, these functions will be retained for some backward compatibility with old code, using the legacy capabilities to try and work out what to do.

==Problem areas we are working on ==

===Student view===

The "Student view" button has been removed completely.

If there is time and a secure way can be found, it will be replaced by a menu to let the user assume a temporary role in the context of that course.

===Teacher forum===

Teacher forums were always a curious exception to normal forums, as they were not part of a course as such, and were not backed up.

We're taking the opportunity to rectify this. The upgrade converts teacher forums with content to normal forums in section 0 of the course, and ensures that only teachers can access them. If the teacher forum had not been used in the course then it's not converted and will just dissappear.

===Enrolment plugins===

====Process of logging in====

(more soon)

====Process of checking access to a course====

require_login($course->id) is called by the script and has logic like this:

# Is the user a guest at site level?
## Yes: Does the course allow guests?
### Yes: return true (and further capabilities are checked by the script)
### No: send the user to course/enrol.php for enrolment
## No: continue below

# Does the user have moodle/course:view in that (course) context?
## Yes: then they can enter (and further capabilities are checked by the script)
## No: is guest access allowed on the course?
### Yes: assign temporary guest role to that user for that context (in session cache).
### No: send the user to course/enrol.php for enrolment.

====Process of enrolling====

(more soon)

==Scenario brainstorming==

This section is for brainstorming some example roles that we would like to support. Note some of these *may* not be possible in 1.7.

===Student===
Obviously.

===Site Designers===
Is there a role for people involved in how the site looks but not full administrators? Thinking here of online control of themes rather than FTP theme uploading. But in either case they caneditlogos, caneditcss, candeditlevelatwhichthemeapplies.

===Educational Authority Adviser===
Someone who would want to browse the site and may be asked to comment or contribute to particular discussions or developments in school. Access for this role would be controlled by the school in the case of school level moodles but may be different if there were to be a Local Authority wide Moodle.

===Educational Inspector===
Someone who will visit the site to verify the school's self review that comments on home school relationships, extending the classroom etc. They may want to see summaries of usage and reports from surveys garnering parent and pupil views.

===Second Marker / Moderator===
A teacher within ths site that has access to assignments and quizzes from another teacher's course for second marking purposes. This may need additional functionality adding to the assignment module so that two sets of grades/feedback can be given to one set of assignments.

===Peer observer of teaching===
Many institutions encourage peer observation of teaching, to encourage reflection on practice. In online environments this will be similar to moderation or inspection. The peer observer would need to be able to experience the course "as a student", but also to be able to view summaries of usage, transcripts of interactions (forums/surveys/polls etc), grades assigned (e.g. in assignments).

===External Examiner===
Has all the rights of inspectors, but would also need to be able to review assignments and feedback, view forums, glossaries etc. However, would not want to post, feedback onto the site at all.

===Parent===
A parent will have one or more children in one or more institutions which could be using one or more moodle instances or a mixture of Learning Platforms. A parent's role will vary depending on the age of their children and whether they are contributing as a parent or a school supporter.

In Early Years (EY=3+4 yr olds) and Key Stage 1 (KS1=5+6 yr olds) they may play/learn on an activity or write for the child. Parents often interpret homework tasks and read to their children perhaps filling in a joint reading diary. In Key Stage 2 (KS2=7-11 yr olds) parents would be more monitoring but may join in as well.

In Key stages 3 (KS3=12-14 yr olds) and 4 (KS4=15+16 yr olds) this changes to more of a monitoring/awareness role where a parent would expect to have a summary report of attendance, attainment and general achievement on a weekly/monthly/termly or annual basis. Parents will often be asked to sign and write back comments about this review report.

In all Key Stages there is a great need for parents to receive communication from the school which they can confirm they have received by signing a form. In some cases this may also involve making choices from a list. It may also involve payment for a trip or disco being returned so there could be the possibility of electronic payments. Also in all Key Satges there may be a home-school agreement which may be signed up to. Could this form part of a site policy system that incorporates a tickable list of activities the parent agrees to the child using (blogs/wikis/forums etc.)?

Parent's evenings often involve complex booking systems that attempt to get parent's and teachers together. Easy for EY/KS1/KS2 very difficult for KS3/KS4. Wow would this help if it was built into the Learning Platform.

In some cases there needs to be confidential communication between the parent and the teacher without the child being party to this. It may involve teaching and learning but could also involve a behaviour or medical issue. Often this may be done via a sealed letter or face to face.

The latest incarnation of OfSTED with the Self Review Framework (SEF) there is a greater emphasis on schools gathering parent voice via surveys and discussion. There is a clear match here with parents have access to parental votes, questionnaires and discussions and for schools to be able to publish news, results and reports back to parents.

In the UK the LP framework and agenda as being pushed by the DfES via Becta emphasises that within the mandatory groups and roles functionality the parent role is likely to be required to meet the LP Framework procurement standard.

Again in the UK, parents have their own independent right of access to a child's educational records. Obviously, children's records must not be made available to other parties, including the parents of other children in the same class. Thus it would be necessary to associate parent accounts with their own child's accounts in such a way that they could, if so desired, have read access to their child's grades, answers and contributions, but generally not those of other children - this may be problematic in the case of wiki activities or forum posts.

There is some concern that children's forum contributions etc may be constrained if their parents are able to read all that they write; this may be particularly problematic in areas such as Personal, Social and Health Education (PSHE), where some schools may choose to use obfuscated usernames.

===Manager===
''Please add text here...''

===Weekly Seminar Leader===
''In a university seminar, typically 8-15 students in their 3rd/4th year, each student is responsible for leading one topic in a study series. I ask each student to research 5-10 resources, then give a powerpoint presentation to the other students. This is followed by an in-class discussion and then online homework. The homework involves some fun quiz questions and then some reflective journal questions. I ask each seminar leader to prepare the quiz questions and journal questions as well as their presentation. To do that, I would like to assign activity-making/authoring roles to the student--either for a short period, or for duration of the whole course. Thus "Allow Quiz Authoring Role" or "Allow Assignment Authoring Role" at the course level or, if possible, even the Topic level (in a topic or week format course) would be important.''

===Mentor/Mentee===
''Please add text here...''

===Community-Designed Rating Criteria===
''The gradebook tends to be the domain of the teacher. What if community/peer ratings/marks could also be entered there? What if peer assessment criteria could be designed by the students, not just the teacher?''

===Visitor===

This would be a role whereby one could allow a visitor to visit one's classroom. This might be a colleague interested in seeing your course, or a journalist who might be writing an article about one's site. They should not be able to see the names of any students anywhere (eg recent activity, forum posts) for privacy reasons. They should be able to try out things like quizzes, and lessons but no grades would be recorded (like in teacher preview mode). They would not be able to participate in choices and forums but could view them. It would be read only in a way like former-student role below but without access to a particular student's records that former student role would grant.

===Guest Speaker===

This role would be similar to the Visitor role above, but would allow seeing student names, and also allow both reading and posting to a specific forum or forums. We often have "guest speakers" who read and respond to student forum posts. Right now we have to add them as students, which isn't ideal.

===Former Student===
This role would be of particular use for courses with rolling enrollments. This role would be one where a student had completed all of the requirements of a course (ie assignments, quizzes etc.) but wished to have continued access to the course material for review or consultation. The key factor is that one would give access to the completed student to the notes he read, his work and the teacher's comments on it, but he would not be allowed to do anything that would take up the teacher's time. In other words, a sort-of read-only access to the course. How forums, which might contain pertinent information and would continue to grow, would be handled is a question. Perhaps the student would be shown only what was in the forums at the time he completed the course. He would not be allowed to see any new posts or add any himself. Same thing for database and glossary entries. In other words, a snapshot of the course at the time his regular enrollment ended. He shouldn't be able to see the names or profiles of any newly enrolled students for privacy reasons-hence the restrictions on forum access. One issue that would have to be dealt with would be changes to existing modules-such as resources. Does the student get access to the module as it was or as it is? We have no versioning of resources in Moodle so this would be a problem. What about a teacher changing a quiz question so that the answer is different? What would a former student see?

===Alumnus=== An ALUMNUS should be able to search for all other ALUMNI of the school, interact with them and be enrolled in a seperate course - which is like a META course with all the content of his learning and interaction - as well as capabilities to be a part of this ALUMNI only course. All the teachers of courses during school years should automatically be a part of the ALUMNI course .. which means when an ALUMNUS is enrolled in a course, the original teachers of all his courses get enrolled ? --[[User:Anil Sharma|Anil Sharma]] 20:54, 15 July 2006 (WST)

===Librarian===

Reference Librarians have an active role in most of the courses taught at some schools such as Earlham College (with Bibliographic Instruction). The Librarian role within Moodle could encompass default read access to all courses (unless prohibited by course teacher) and read access to all components of the course unless access is barred (again by teacher). The Librarians would also perhaps have a block called perhaps Reference Services or Reference Desk with write access where they could deposit resources. Also this block might have a chat applet whereby enrolled students could chat to the Reference Librarian on duty about their bibliographic research needs.

In schools there is often a book review system. This may be covered by the lending system database but may not in which case a librarian may neeed to have a course area they can create a database template to handle the reviews in which case they may have a normal teacher style role? Off topic but course an integration with common schools database systems would be great.

===Teacher===

Teachers should have read access to other Teacher's courses unless explictly prohibited. They should be able to set parts of their own course to be totally private (perhaps even to admin?). Just as each activity can currently be set to have group access, each activity could have a permissions field. Teachers could set default permissions for all activities on their course (eg they might disallow Librarian access for example) and then change the access permission for an individual activity.

I think that what is needed is a simple heirarchy of permissions and levels of granularity.

I would take issue with "teachers should have read access to other teacher's courses unless explicitly prohibited." This is a violation of the students' privacy as how they perform and what they do in one class isn't the business of another teacher. Moreover, in the real world a teacher wouldn't suddenly go sit in on a colleague's class without asking permission first. I would not have appreciated such an invasion of privacy as either a teacher or a student. It could be an option, but shouldn't be default.--[[User:N Hansen|N Hansen]] 19:54, 12 June 2006 (WST)

===Community Education Tutors/Trainers===
Teachers may be community adult education trainers making use of a school moodle so must only have access to their courses unless given access elsewhere. They would not necessarily get the default teacher privileges.

===Secretary/Student Worker===

We often have faculty who want their departmental secretary or student worker to scan and upload files and perhaps create resources. Currently they have to be given teacher access to the course. This is dangerous from a FERPA standpoint since they could easily get access to grades.

===Teaching Assistant===

Our Faculty frequently have undergraduate students acting as Teaching Assistants. These students need to be able to add resources, create assignments, and possibly grade assignments. However, due to FERPA they cannot have access to other students' overall grade information. I think the requirements here are slightly different than those of Secretary/Student Worker

===Student - FERPA rights===

A student that has asserted their FERPA rights to non-disclosure. Typically includes not publishing their name
in any public place. Could include this student only being seen with an "alias" within course spaces. Is this an attribute rather
than a role?

===Help Desk===

Help desk agents that have read access for the purposes of trouble shooting. Some care in placing this role within a hierarchy
of inheritance is needed, full access will be problematic with FERPA.

===Admin - Catgory based===

Basically a person in between full Admin and Creator that has the permissions of an Admin but only with respect to courses and students. Currently a Creator has permissions site-wide which does not always meet the requirements of a given organisation (e.g. Department A may not be happy that a person from Department B can create/modify courses within Department A's area). The ability to designate a Creator within a specific category would allow areas to be set up for a faculty/department/organisation and allow the Admin for that area to create/delete courses, upload users, add site-wide entries to the calendar etc.

===PROCESS ROLES===

organising the learning process for a group you wish to have the choice to place students in differnt roles: examples of this are:
<li>1. Give a student the role of forum-moderator with edit and chunk-rights
<li>2. Give students different roles & rights in a Webquest design (and change these roles next week
<li>3. Give students different resources, depending of their roles in a rolegame/simulation
<li>4. Give a student the rights to create the section content of next week (and only that week..)
<li>5. ..

==See also==

*Using Moodle [http://moodle.org/mod/forum/discuss.php?d=38788 Roles and Permissions architecture] forum discussion

[[Category:Developer]]
[[Category:Future]]
[[Category:Roles]]

You Might Be a Moodler

2006-09-02T19:28:55Z

Davidberry:

In the spirit of Jeff Foxworthy's ''You Might be a Redneck'' - http://www.jefffoxworthy.com/comedy/jod/index.shtml

*If you have ever turned on a football game and and the orange uniforms of one team caused you to leap up from the sofa and check out moodle.org, you might be a Moodler.

*If you type "moodle.org" in your browser when you intend to type "google.com."

*If you can spell '''Dougiamas''' without having to look it up.

*If you check the Moodle forums at 8:30 on a Saturday night.

Development:Blogs

2006-06-20T10:31:32Z

Davidberry: /* Blog entry resume */

== Blogs Wishlist==
Its great to have blogs on Moodle, but we should expect more of Moodle's blogs. Let's make a wishlist.
=== How do I link to a specific Blog entry ? ===
The so called blogosphere bores out of the inter-linking between blog entries, but right now you don't know how to link to a concrete blog entry. Blog entries should have a link to refer themselves. We can only link user's blogs to categories.

=== Blog entry resume ===
A view of the blogs entries that gives only 3-5 lines of the blog entry, so a reader can view a lot of entries on one site and click on a "continue reading" link or so on.

=== Block Blog Tools ===
Some blog tools to view blog entries that wolud be nice to have:
* Last Blog entries.
** per user
** per category
** per course
** per site
* Blog search
* Most readed, commented voted blog entries ( and vote for blog entry, of course )

[[Category:Developer]]
[[Category:Blog]]

Development:Blogs

2006-06-20T10:30:10Z

Davidberry: /* How do I link to a specific Blog entry ? */

== Blogs Wishlist==
Its great to have blogs on Moodle, but we should expect more of Moodle's blogs. Let's make a wishlist.
=== How do I link to a specific Blog entry ? ===
The so called blogosphere bores out of the inter-linking between blog entries, but right now you don't know how to link to a concrete blog entry. Blog entries should have a link to refer themselves. We can only link user's blogs to categories.

=== Blog entry resume ===
A view of the blogs entries that gives only 3-5 lines of the blog entry, so a reader can view a lot of entries in one sigth and click on a "continue reading" link or so on.
=== Block Blog Tools ===
Some blog tools to view blog entries that wolud be nice to have:
* Last Blog entries.
** per user
** per category
** per course
** per site
* Blog search
* Most readed, commented voted blog entries ( and vote for blog entry, of course )

[[Category:Developer]]
[[Category:Blog]]

Development:Blocks

2006-04-11T06:24:19Z

Davidberry: /* The Specialists */

''' A Step-by-step Guide To Creating Blocks '''

Original Author: Jon Papaioannou (pj@uom.gr)

The present document serves as a guide to developers who want to create their own blocks for use in Moodle. It applies to the 1.5 development version of Moodle (and any newer) '''only''', as the blocks subsystem was rewritten and expanded for the 1.5 release. However, you can also find it useful if you want to modify blocks written for Moodle 1.3 and 1.4 to work with the latest versions (look at [[Blocks_Howto#appendix_b| Appendix B]]).
The guide is written as an interactive course which aims to develop a configurable, multi-purpose block that displays arbitrary HTML. It's targeted mainly at people with little experience with Moodle or programming in general and aims to show how easy it is to create new blocks for Moodle. A certain small amount of PHP programming knowledge is still required, though. Experienced developers and those who just want a reference text should refer to [[Blocks_Howto#appendix_a| Appendix A]] because the main guide has a rather low concentration of pure information in the text.

== Basic Concepts ==
Through this guide, we will be following the creation of an "HTML" block from scratch in order to demonstrate most of the block features at our disposal. Our block will be named "SimpleHTML". This does not constrain us regarding the name of the actual directory on the server where the files for our block will be stored, but for consistency we will follow the practice of using the lowercased form "simplehtml" in any case where such a name is required. Whenever we refer to a file or directory name which contains "simplehtml", it's important to remember that ''only'' the "simplehtml" part is up to us to change; the rest is standardized and essential for Moodle to work correctly.
Whenever a file's path is mentioned in this guide, it will always start with a slash. This refers to the Moodle home directory; all files and directories will be referred to with respect to that directory.

== Ready, Set, Go! ==
To define a "block" in Moodle, in the most basic case we need to provide just one source code file. We start by creating the directory <span class="filename">/blocks/simplehtml/</span> and creating a file named <span class="filename">/blocks/simplehtml/block_simplehtml.php</span> which will hold our code. We then begin coding the block:
class block_simplehtml extends block_base {
function init() {
$this->title = get_string('simplehtml', 'block_simplehtml');
$this->version = 2004111200;
}
}
The first line is our block class definition; it must be named exactly in the manner shown. Again, only the "simplehtml" part can (and indeed must) change; everything else is standardized.
Our class is then given a small method: [[Blocks_Howto#method_init| init]]. This is essential for all blocks, and its purpose is to set the two class member variables listed inside it. But what do these values actually mean? Here's a more detailed description.
[[Blocks_Howto#variable_title| $this->title]] is the title displayed in the header of our block. We can set it to whatever we like; in this case it's set to read the actual title from a language file we are presumably distributing together with the block. I 'll skip ahead a bit here and say that if you want your block to display '''no''' title at all, then you should set this to any descriptive value you want (but '''not''' make it an empty string). We will later see [[Blocks_Howto#section_eye_candy| how to disable the title's display]].
[[Blocks_Howto#variable_version| $this->version]] is the version of our block. This actually would only make a difference if your block wanted to keep its own data in special tables in the database (i.e. for very complex blocks). In that case the version number is used exactly as it's used in activities; an upgrade script uses it to incrementally upgrade an "old" version of the block's data to the latest. We will outline this process further ahead, since blocks tend to be relatively simple and not hold their own private data. In our example,
this is certainly the case so we just set [[Blocks_Howto#variable_version| $this->version]] to '''YYYYMMDD00''' and forget about it.
'''UPDATING:''' Prior to version 1.5, the basic structure of each block class was slightly different. Refer to [[Blocks_Howto#appendix_b| Appendix B]] for more information on the changes that old blocks have to make to conform to the new standard.
== I Just Hear Static ==
In order to get our block to actually display something on screen, we need to add one more method to our class (before the final closing brace in our file). The new code is:
function get_content() {
if ($this->content !== NULL) {
return $this->content;
}

$this->content = new stdClass;
$this->content->text = 'The content of our SimpleHTML block!';
$this->content->footer = 'Footer here...';

return $this->content;
}
It can't get any simpler than that, can it? Let's dissect this method to see what's going on...
First of all, there is a check that returns the current value of [[Blocks_Howto#variable_content| $this->content]] if it's not NULL; otherwise we proceed with "computing" it. Since the computation is potentially a time-consuming operation and it '''will''' be called several times for each block (Moodle works that way internally), we take a precaution and include this time-saver.
Supposing the content had not been computed before (it was NULL), we then define it from scratch. The code speaks for itself there, so there isn't much to say. Just keep in mind that we can use HTML both in the text '''and''' in the footer, if we want to.
At this point our block should be capable of being automatically installed in Moodle and added to courses; visit your administration page to install it and after seeing it in action come back to continue our tutorial.
== Configure That Out ==
The current version of our block doesn't really do much; it just displays a fixed message, which is not very useful. What we 'd really like to do is allow the teachers to customize what goes into the block. This, in block-speak, is called "instance configuration". So let's give our block some instance configuration...
First of all, we need to tell Moodle that we want it to provide instance-specific configuration amenities to our block. That's as simple as adding one more method to our block class:
function instance_allow_config() {
return true;
}
This small change is enough to make Moodle display an "Edit..." icon in our block's header when we turn editing mode on in any course. However, if you try to click on that icon you will be presented with a notice that complains about the block's configuration not being implemented correctly. Try it, it's harmless.
Moodle's complaints do make sense. We told it that we want to have configuration, but we didn't say ''what'' kind of configuration we want, or how it should be displayed. To do that, we need to create one more file: <span class="filename">/blocks/simplehtml/config_instance.html</span> (which has to be named exactly like that). For the moment, copy paste the following into it and save:
<nowiki>
<table cellpadding="9" cellspacing="0">
<tr valign="top">
<td align="right">
<?php print_string('configcontent', 'block_simplehtml'); ?>:
</td>
<td>
<?php print_textarea(true, 10, 50, 0, 0, 'text', $this->config->text); ?>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<input type="submit" value="<?php print_string('savechanges') ?>" />
</td>
</tr>
</table>
<?php use_html_editor(); ?>
</nowiki>
It isn't difficult to see that the above code just provides us with a wysiwyg-editor-enabled textarea to write our block's desired content in and a submit button to save. But... what's $this->config->text? Well...
Moodle goes a long way to make things easier for block developers. Did you notice that the textarea is actually named "text"? When the submit button is pressed, Moodle saves each and every field it can find in our <span class="filename">config_instance.html</span> file as instance configuration data. We can then access that data as '''$this->config->''variablename''''', where ''variablename'' is the actual name we used for our field; in this case, "text". So in essence, the above form just pre-populates the textarea with the current content of the block (as indeed it should) and then allows us to change it.
You also might be surprised by the presence of a submit button and the absence of any <form> element at the same time. But the truth is, we don't need to worry about that at all; Moodle goes a really long way to make things easier for developers! We just print the configuration options we want, in any format we want; include a submit button, and Moodle will handle all the rest itself. The instance configuration variables are automatically at our disposal to access from any of the class methods ''except'' [[Blocks_Howto#method_init| init]].
In the event where the default behavior is not satisfactory, we can still override it. However, this requires advanced modifications to our block class and will not be covered here; refer to [[Blocks_Howto#appendix_a| Appendix A]] for more details.
Having now the ability to refer to this instance configuration data through [[Blocks_Howto#variable_config| $this->config]], the final twist is to tell our block to actually ''display'' what is saved in is configuration data. To do that, find this snippet in <span class="filename">/blocks/simplehtml/block_simplehtml.php</span><nowiki>:</nowiki>

$this->content = new stdClass;
$this->content->text = 'The content of our SimpleHTML block!';
$this->content->footer = 'Footer here...';
and change it to:

$this->content = new stdClass;
$this->content->text = $this->config->text;
$this->content->footer = 'Footer here...';
Oh, and since the footer isn't really exciting at this point, we remove it from our block because it doesn't contribute anything. We could just as easily have decided to make the footer configurable in the above way, too. So for our latest code, the snippet becomes:
<nowiki>
$this->content = new stdClass;
$this->content->text = $this->config->text;
$this->content->footer = '';</nowiki>
After this discussion, our block is ready for prime time! Indeed, if you now visit any course with a SimpleHTML block, you will see that modifying its contents is now a snap.

== The Specialists ==
Implementing instance configuration for the block's contents was good enough to whet our appetite, but who wants to stop there? Why not customize the block's title, too?
Why not, indeed. Well, our first attempt to achieve this is natural enough: let's add another field to <span class="filename">/blocks/simplehtml/config_instance.html</span>. Here goes:
<nowiki>
<tr valign="top">
<td align="right"><p><?php print_string('configtitle', 'block_simplehtml'); ?>:</td>
<td><input type="text" name="title" size="30" value="<?php echo $this->config->title; ?>" /></td>
</tr>
</nowiki>
We save the edited file, go to a course, edit the title of the block and... nothing happens! The instance configuration is saved correctly, all right (editing it once more proves that) but it's not being displayed. All we get is just the simple "SimpleHTML" title.
That's not too wierd, if we think back a bit. Do you remember that [[Blocks_Howto#method_init| init]] method, where we set [[Blocks_Howto#variable_title| $this->title]]? We didn't actually change its value from then, and [[Blocks_Howto#variable_title| $this->title]] is definitely not the same as $this->config->title (to Moodle, at least). What we need is a way to update [[Blocks_Howto#variable_title| $this->title]] with the value in the instance configuration. But as we said a bit earlier, we can use [[Blocks_Howto#variable_config| $this->config]] in all methods ''except'' [[Blocks_Howto#method_init| init]]<nowiki>! So what can we do?</nowiki>
Let's pull out another ace from our sleeve, and add this small method to our block class:

function specialization() {
$this->title = $this->config->title;
}
Aha, here's what we wanted to do all along! But what's going on with the [[Blocks_Howto#method_specialization| specialization]] method?
This "magic" method has actually a very nice property: it's ''guaranteed'' to be automatically called by Moodle as soon as our instance configuration is loaded and available (that is, immediately after [[Blocks_Howto#method_init| init]] is called). That means before the block's content is computed for the first time, and indeed before ''anything'' else is done with the block. Thus, providing a [[Blocks_Howto#method_specialization| specialization]] method is the natural choice for any configuration data that needs to be acted upon "as soon as possible", as in this case.

== Now You See Me, Now You Don't ==
Now would be a good time to mention another nifty technique that can be used in blocks, and which comes in handy quite often. Specifically, it may be the case that our block will have something interesting to display some of the time; but in some other cases, it won't have anything useful to say. (An example here would be the "Recent Activity" block, in the case where no recent activity in fact exists. However in that case the block chooses to explicitly inform you of the lack of said activity, which is arguably useful). It would be nice, then, to be able to have our block "disappear" if it's not needed to display it.
This is indeed possible, and the way to do it is to make sure that after the [[Blocks_Howto#method_get_content| get_content]]<nowiki> method is called, the block is completely void of content. Specifically, "void of content" means that both $this->content->text and $this->content->footer are each equal to the empty string (''). Moodle performs this check by calling the block's </nowiki>[[Blocks_Howto#method_is_empty| is_empty()]] method, and if the block is indeed empty then it is not displayed at all.
Note that the exact value of the block's title and the presence or absence of a [[Blocks_Howto#method_hide_header| hide_header]] method do ''not'' affect this behavior. A block is considered empty if it has no content, irrespective of anything else.
== We Are Legion ==
Right now our block is fully configurable, both in title and content. It's so versatile, in fact, that we could make pretty much anything out of it. It would be really nice to be able to add multiple blocks of this type to a single course. And, as you might have guessed, doing that is as simple as adding another small method to our block class:

function instance_allow_multiple() {
return true;
}
This tells Moodle that it should allow any number of instances of the SimpleHTML block in any course. After saving the changes to our file, Moodle immediately allows us to add multiple copies of the block without further ado!
There are a couple more of interesting points to note here. First of all, even if a block itself allows multiple instances in the same page, the administrator still has the option of disallowing such behavior. This setting can be set separately for each block from the Administration / Configuration / Blocks page.
And finally, a nice detail is that as soon as we defined an [[Blocks_Howto#method_instance_allow_multiple| instance_allow_multiple]] method, the method [[Blocks_Howto#method_instance_allow_config| instance_allow_config]] that was already defined became obsolete. Moodle assumes that if a block allows multiple instances of itself, those instances will want to be configured (what is the point of same multiple instances in the same page if they are identical?) and thus automatically provides an "Edit" icon. So, we can also remove the whole [[Blocks_Howto#method_instance_allow_config| instance_allow_config]] method now without harm. We had only needed it when multiple instances of the block were not allowed.
== The Effects of Globalization ==
Configuring each block instance with its own personal data is cool enough, but sometimes administrators need some way to "touch" all instances of a specific block at the same time. In the case of our SimpleHTML block, a few settings that would make sense to apply to all instances aren't that hard to come up with. For example, we might want to limit the contents of each block to only so many characters, or we might have a setting that filters HTML out of the block's contents, only allowing pure text in. Granted, such a feature wouldn't win us any awards for naming our block "SimpleHTML" but some tormented administrator somewhere might actually find it useful.
This kind of configuration is called "global configuration" and applies only to a specific block type (all instances of that block type are affected, however). Implementing such configuration for our block is quite similar to implementing the instance configuration. We will now see how to implement the second example, having a setting that only allows text and not HTML in the block's contents.
First of all, we need to tell Moodle that we want our block to provide global configuration by, what a surprise, adding a small method to our block class:

function has_config() {
return true;
}
Then, we need to create a HTML file that actually prints out the configuration screen. In our case, we 'll just print out a checkbox saying "Do not allow HTML in the content" and a "submit" button. Let's create the file <span class="filename">/blocks/simplehtml/config_global.html</span> which again must be named just so, and copy paste the following into it:

<div style="text-align: center;">
<input type="hidden" name="block_simplehtml_strict" value="0" />
<input type="checkbox" name="block_simplehtml_strict" value="1"
<?php if(!empty($CFG->block_simplehtml_strict)) echo 'checked="checked"'; ?> />
<?php print_string('donotallowhtml', 'block_simplehtml'); ?>
<p><input type="submit" value="<?php print_string('savechanges'); ?>" /></p>
</div>
True to our block's name, this looks simple enough. What it does is that it displays a checkbox named "block_simplehtml_strict" and if the Moodle configuration variable with the same name (i.e., $CFG->block_simplehtml_strict) is set and not empty (that means it's not equal to an empty string, to zero, or to boolean false) it displays the box as pre-checked (reflecting the current status). Why does it check the configuration setting with the same name? Because the default implementation of the global configuration saving code takes all the variables we have in our form and saves them as Moodle configuration options with the same name. Thus, it's good practice to use a descriptive name and also one that won't possibly conflict with the name of another setting. "block_simplehtml_strict" clearly satisfies both requirements.
The astute reader may have noticed that we actually have ''two'' input fields named "block_simplehtml_strict" in our configuration file. One is hidden and its value is always 0; the other is the checkbox and its value is 1. What gives? Why have them both there?
Actually, this is a small trick we use to make our job as simple as possible. HTML forms work this way: if a checkbox in a form is not checked, its name does not appear at all in the variables passed to PHP when the form is submitted. That effectively means that, when we uncheck the box and click submit, the variable is not passed to PHP at all. Thus, PHP does not know to update its value to "0", and our "strict" setting cannot be turned off at all once we turn it on for the first time. Not the behavior we want, surely.
However, when PHP handles received variables from a form, the variables are processed in the order in which they appear in the form. If a variable comes up having the same name with an already-processed variable, the new value overwrites the old one. Taking advantage of this, our logic runs as follows: the variable "block_simplehtml_strict" is first unconditionally set to "0". Then, ''if'' the box is checked, it is set to "1", overwriting the previous value as discussed. The net result is that our configuration setting behaves as it should.
To round our bag of tricks up, notice that the use of if(!empty($CFG->block_simplehtml_strict)) in the test for "should the box be checked by default?" is quite deliberate. The first time this script runs, the variable $CFG->block_simplehtml_strict will not exist at all. After it's set for the first time, its value can be either "0" or "1". Given that both "not set" and the string "0" evaluate as empty while the sting "1" does not, we manage to avoid any warnings from PHP regarding the variable not being set at all, ''and'' have a nice human-readable representation for its two possible values ("0" and "1").
Now that we have managed to cram a respectable amount of tricks into a few lines of HTML, we might as well discuss the alternative in case that tricks are not enough for a specific configuration setup we have in mind. Saving the data is done in the method [[Blocks_Howto#method_config_save| config_save]], the default implementation of which is as follows:

function config_save($data) {
// Default behavior: save all variables as $CFG properties
foreach ($data as $name => $value) {
set_config($name, $value);
}
return true;
}
As can be clearly seen, Moodle passes this method an associative array $data which contains all the variables coming in from our configuration screen. If we wanted to do the job without the "hidden variable with the same name" trick we used above, one way to do it would be by overriding this method with the following:

function config_save($data) {
if(isset($data['block_simplehtml_strict'])) {
set_config('block_simplehtml_strict', '1');
}
else {
set_config('block_simplehtml_strict', '0');
}
return true;
}
Quite straightfoward: if the variable "block_simplehtml_strict" is passed to us, then it can only mean that the user has checked it, so set the configuration variable with the same name to "1". Otherwise, set it to "0". Of course, this version would need to be updated if we add more configuration options because it doesn't respond to them as the default implementation does. Still, it's useful to know how we can override the default implementation if it does not fit our needs (for example, we might not want to save the variable as part of the Moodle configuration but do something else with it).
So, we are now at the point where we know if the block should allow HTML tags in its content or not. How do we get the block to actually respect that setting?
We could decide to do one of two things: either have the block "clean" HTML out from the input before saving it in the instance configuration and then display it as-is (the "eager" approach); or have it save the data "as is" and then clean it up each time just before displaying it (the "lazy" approach). The eager approach involves doing work once when saving the configuration; the lazy approach means doing work each time the block is displayed and thus it promises to be worse performance-wise. We shall hence go with the eager approach.
Much as we did just before with overriding [[Blocks_Howto#method_config_save| config_save]], what is needed here is overriding the method [[Blocks_Howto#method_instance_config_save| instance_config_save]] which handles the instance configuration. The default implementation is as follows:

function instance_config_save($data) {
$data = stripslashes_recursive($data);
$this->config = $data;
return set_field('block_instance', 'configdata', base64_encode(serialize($data)),
'id', $this->instance->id);
}
This may look intimidating at first (what's all this stripslashes_recursive() and base64_encode() and serialize() stuff?) but do not despair; we won't have to touch any of it. We will only add some extra validation code in the beginning and then instruct Moodle to additionally call this default implementation to do the actual storing of the data. Specifically, we will add a method to our class which goes like this:

function instance_config_save($data) {
// Clean the data if we have to
global $CFG;
if(!empty($CFG->block_simplehtml_strict)) {
$data['text'] = strip_tags($data['text']);
}

// And now forward to the default implementation defined in the parent class
return parent::instance_config_save($data);
}
At last! Now the administrator has absolute power of life and death over what type of content is allowed in our "SimpleHTML" block! Absolute? Well... not exactly. In fact, if we think about it for a while, it will become apparent that if at some point in time HTML is allowed and some blocks have saved their content with HTML included, and afterwards the administrator changes the setting to "off", this will only prevent subsequent content changes from including HTML. Blocks which already had HTML in their content would continue to display it!
Following that train of thought, the next stop is realizing that we wouldn't have this problem if we had chosen the lazy approach a while back, because in that case we would "sanitize" each block's content just before it was displayed. The only thing we can do with the eager approach is strip all the tags from the content of all SimpleHTML instances as soon as the admin setting is changed to "HTML off"; but even then, turning the setting back to "HTML on" won't bring back the tags we stripped away. On the other hand, the lazy approach might be slower, but it's more versatile; we can choose whether to strip or keep the HTML before displaying the content, and we won't lose it at all if the admin toggles the setting off and on again. Isn't the life of a developer simple and wonderful?
We will let this part of the tutorial come to a close with the obligatory excercise for the reader: in order to have the SimpleHTML block work "correctly", find out how to strengthen the eager approach to strip out all tags from the existing configuration of all instances of our block, '''or''' go back and implement the lazy approach instead. (Hint: do that in the [[Blocks_Howto#method_get_content| get_content]] method)
'''UPDATING'''<nowiki>: Prior to version 1.5, the file </nowiki><span class="filename">config_global.html</span> was named simply <span class="filename">config.html</span>. Also, the methods [[Blocks_Howto#method_config_save| config_save]] and [[Blocks_Howto#method_config_print| config_print]] were named '''handle_config''' and '''print_config''' respectively. Upgrading a block to work with Moodle 1.5 involves updating these aspects; refer to [[Blocks_Howto#appendix_b| Appendix B]] for more information.
== Eye Candy ==
Our block is just about complete functionally, so now let's take a look at some of the tricks we can use to make its behavior customized in a few more useful ways.
First of all, there are a couple of ways we can adjust the visual aspects of our block. For starters, it might be useful to create a block that doesn't display a header (title) at all. You can see this effect in action in the Course Description block that comes with Moodle. This behavior is achieved by, you guessed it, adding one more method to our block class:

function hide_header() {
return true;
}
One more note here: we cannot just set an empty title inside the block's [[Blocks_Howto#method_init| init]] method; it's necessary for each block to have a unique, non-empty title after [[Blocks_Howto#method_init| init]] is called so that Moodle can use those titles to differentiate between all of the installed blocks.
Another adjustment we might want to do is instruct our block to take up a certain amount of width on screen. Moodle handles this as a two-part process: first, it queries each block about its preferred width and takes the maximum number as the desired value. Then, the page that's being displayed can choose to use this value or, more probably, bring it within some specific range of values if it isn't already. That means that the width setting is a best-effort settlement; your block can ''request'' a certain width and Moodle will ''try'' to provide it, but there's no guarantee whatsoever about the end result. As a concrete example, all standard Moodle course formats will deliver any requested width between 180 and 210 pixels, inclusive.
To instruct Moodle about our block's preferred width, we add one more method to the block class:

function preferred_width() {
// The preferred value is in pixels
return 200;
}
This will make our block (and all the other blocks displayed at the same side of the page) a bit wider than standard.
Finally, we can also affect some properties of the actual HTML that will be used to print our block. Each block is fully contained within a <table> element, inside which all the HTML for that block is printed. We can instruct Moodle to add HTML attributes with specific values to that container. This would be done to either a) directly affect the end result (if we say, assign bgcolor="black"), or b) give us freedom to customize the end result using CSS (this is in fact done by default as we 'll see below).
The default behavior of this feature in our case will assign to our block's container the class HTML attribute with the value "sideblock block_simplehtml" (the prefix "block_" followed by the name of our block, lowercased). We can then use that class to make CSS selectors in our theme to alter this block's visual style (for example, ".sideblock.block_simplehtml { border: 1px black solid}").
To change the default behavior, we will need to define a method which returns an associative array of attribute names and values. For example, the version

function html_attributes() {
return array(
'class' => 'sideblock block_'. $this->name(),
'onmouseover' => 'alert("Mouseover on our block!");'
);
}
will result in a mouseover event being added to our block using JavaScript, just as if we had written the onmouseover="alert(...)" part ourselves in HTML. Note that we actually duplicate the part which sets the class attribute (we want to keep that, and since we override the default behavior it's our responsibility to emulate it if required). And the final elegant touch is that we don't set the class to the hard-coded value "block_simplehtml" but instead use the [[Blocks_Howto#method_name| name]] method to make it dynamically match our block's name.

== Authorized Personnel Only ==
It's not difficult to imagine a block which is very useful in some circumstances but it simply cannot be made meaningful in others. An example of this would be the "Social Activities" block which is indeed useful in a course with the social format, but doesn't do anything useful in a course with the weeks format. There should be some way of allowing the use of such blocks only where they are indeed meaningful, and not letting them confuse users if they are not.
Moodle allows us to declare which course formats each block is allowed to be displayed in, and enforces these restrictions as set by the block developers at all times. The information is given to Moodle as a standard associative array, with each key corresponding to a page format and defining a boolean value (true/false) that declares whether the block should be allowed to appear in that page format.
Notice the deliberate use of the term ''page'' instead of ''course'' in the above paragraph. This is because in Moodle 1.5 and onwards, blocks can be displayed in any page that supports them. The best example of such pages are the course pages, but we are not restricted to them. For instance, the quiz view page (the first one we see when we click on the name of the quiz) also supports blocks.
The format names we can use for the pages derive from the name of the script which is actually used to display that page. For example, when we are looking at a course, the script is <span class="filename">/course/view.php</span> (this is evident from the browser's address line). Thus, the format name of that page is '''course-view'''. It follows easily that the format name for a quiz view page is '''mod-quiz-view'''. This rule of thumb does have a few exceptions, however:
#* The format name for the front page of Moodle is '''site-index'''.
#* The format name for courses is actually not just '''course-view'''<nowiki>; it is </nowiki>'''course-view-weeks''', '''course-view-topics''', etc.
#* Even though there is no such page, the format name '''all''' can be used as a catch-all option.
We can include as many format names as we want in our definition of the applicable formats. Each format can be allowed or disallowed, and there are also three more rules that help resolve the question "is this block allowed into this page or not?":
#* Prefixes of a format name will match that format name; for example, '''mod''' will match all the activity modules. '''course-view''' will match any course, regardless of the course format. And finally, '''site''' will also match the front page (remember that its full format name is '''site-index''').
#* The more specialized a format name that matches our page is, the higher precedence it has when deciding if the block will be allowed. For example, '''mod''', '''mod-quiz''' and '''mod-quiz-view''' all match the quiz view page. But if all three are present, '''mod-quiz-view''' will take precedence over the other two because it is a better match.
#* The character '''<nowiki>*</nowiki>''' can be used in place of any word. For example, '''mod''' and '''mod-*''' are equivalent. At the time of this document's writing, there is no actual reason to utilize this "wildcard matching" feature, but it exists for future usage.
#* The order that the format names appear does not make any difference.
All of the above are enough to make the situation sound complex, so let's look at some specific examples. First of all, to have our block appear '''only''' in the site front page, we would use:

function applicable_formats() {
return array('site' => true);
}
Since '''all''' is missing, the block is disallowed from appearing in ''any'' course format; but then '''site''' is set to true, so it's explicitly allowed to appear in the site front page (remember that '''site''' matches '''site-index''' because it's a prefix).
For another example, if we wanted to allow the block to appear in all course formats ''except'' social, and also to ''not'' be allowed anywhere but in courses, we would use:

function applicable_formats() {
return array('course-view' => true, 'course-view-social' => false);
}
This time, we first allow the block to appear in all courses and then we explicitly disallow the social format.
For our final, most complicated example, suppose that a block can be displayed in the site front page, in courses (but not social courses) and also when we are viewing any activity module, ''except'' quiz. This would be:

function applicable_formats() {
return array('site-index' => true,
'course-view' => true, 'course-view-social' => false,
'mod' => true, 'mod-quiz' => false);
}
It is not difficult to realize that the above accomplishes the objective if we remember that there is a "best match" policy to determine the end result.
'''UPDATING:''' Prior to version 1.5, blocks were only allowed in courses (and in Moodle 1.4, in the site front page). Also, the keywords used to describe the valid course formats at the time were slightly different and had to be changed in order to allow for a more open architecture. Refer to [[Blocks_Howto#appendix_b| Appendix B]] for more information on the changes that old blocks have to make to conform to the new standard.
== Lists and Icons ==
In this final part of the guide we will briefly discuss an additional capability of Moodle's block system, namely the ability to very easily create blocks that display a list of choices to the user. This list is displayed with one item per line, and an optional image (icon) next to the item. An example of such a ''list block'' is the standard Moodle "admin" block, which illustrates all the points discussed in this section.
As we have seen so far, blocks of use two properties of [[Blocks_Howto#variable_content| $this->content]]<nowiki>: "text" and "footer". The text is displayed as-is as the block content, and the footer is displayed below the content in a smaller font size. List blocks use $this->content->footer in the exact same way, but they ignore $this->content->text.</nowiki>
Instead, Moodle expects such blocks to set two other properties when the [[Blocks_Howto#method_get_content| get_content]] method is called: $this->content->items and $this->content->icons. $this->content->items should be a numerically indexed array containing elements that represent the HTML for each item in the list that is going to be displayed. Usually these items will be HTML anchor tags which provide links to some page. $this->content->icons should also be a numerically indexed array, with exactly as many items as $this->content->items has. Each of these items should be a fully qualified HTML <img> tag, with "src", "height", "width" and "alt" attributes. Obviously, it makes sense to keep the images small and of a uniform size.
In order to tell Moodle that we want to have a list block instead of the standard text block, we need to make a small change to our block class declaration. Instead of extending class '''block_base''', our block will extend class '''block_list'''. For example:

class block_my_menu extends block_list {
// The init() method does not need to change at all
}
In addition to making this change, we must of course also modify the [[Blocks_Howto#method_get_content| get_content]] method to construct the [[Blocks_Howto#variable_content| $this->content]] variable as discussed above:

function get_content() {
if ($this->content !== NULL) {
return $this->content;
}

$this->content = new stdClass;
$this->content->items = array();
$this->content->icons = array();
$this->content->footer = 'Footer here...';

$this->content->items[] = '<a href="some_file.php">Menu Option 1</a>';
$this->content->icons[] = '<img src="images/icons/1.gif" width="16" height="16" alt="" />';

// Add more list items here

return $this->content;
}
To summarize, if we want to create a list block instead of a text block, we just need to change the block class declaration and the [[Blocks_Howto#method_get_content| get_content]] method. Adding the mandatory [[Blocks_Howto#method_init| init]] method as discussed earlier will then give us our first list block in no time!

== Appendix A: Reference ==

This Appendix will discuss the base class '''block_base''' from which all other block classes derive, and present each and every method that can be overridden by block developers in detail. Methods that should '''not''' be overridden are explicitly referred to as such. After reading this Appendix, you will have a clear understanding of every method which you should or could override to implement functionality for your block.

The methods are divided into three categories: those you may use and override in your block, those that you may '''not''' override but might want to use, and those internal methods that should '''neither''' be used '''nor''' overridden. In each category, methods are presented in alphabetical order.

=== Methods you can freely use and override: ===
** <div class="function_title">applicable_formats</div>

function applicable_formats() {
// Default case: the block can be used in courses and site index, but not in activities
return array('all' => true, 'mod' => false);
}
This method allows you to control which pages your block can be added to. Page formats are formulated from the full path of the script that is used to display that page. You should return an array with the keys being page format names and the values being booleans (true or false). Your block is only allowed to appear in those formats where the value is true.
Example format names are: '''course-view''', '''site-index''' (this is an exception, referring front page of the Moodle site), '''course-format-weeks''' (referring to a specific course format), '''mod-quiz''' (referring to the quiz module) and '''all''' (this will be used for those formats you have not explicitly allowed or disallowed).
The full matching rules are:
*** Prefixes of a format name will match that format name; for example, '''mod''' will match all the activity modules. '''course-view''' will match any course, regardless of the course format. And finally, '''site''' will also match the front page (remember that its full format name is '''site-index''').
*** The more specialized a format name that matches our page is, the higher precedence it has when deciding if the block will be allowed. For example, '''mod''', '''mod-quiz''' and '''mod-quiz-view''' all match the quiz view page. But if all three are present, '''mod-quiz-view''' will take precedence over the other two because it is a better match.
*** The character '''<nowiki>*</nowiki>''' can be used in place of any word. For example, '''mod''' and '''mod-*''' are equivalent. At the time of this document's writing, there is no actual reason to utilize this "wildcard matching" feature, but it exists for future usage.
*** The order that the format names appear does not make any difference.
** <div class="function_title">config_print</div>
<nowiki>
function config_print() {
// Default behavior: print the config_global.html file
// You don't need to override this if you're satisfied with the above
if (!$this->has_config()) {
return false;
}
global $CFG, $THEME;
print_simple_box_start('center', '', $THEME->cellheading);
include($CFG->dirroot.'/blocks/'. $this->name() .'/config_global.html');
print_simple_box_end();
return true;
}</nowiki>
This method allows you to choose how to display the global configuration screen for your block. This is the screen that the administrator is presented with when he chooses "Settings..." for a specific block. Override it if you need something much more complex than the default implementation allows you to do. However, keep these points in mind:
**# If you save your configuration options in $CFG, you will probably need to use global $CFG; before including any HTML configuration screens.
**# The HTML <input> elements that you include in your method's output will be automatically enclosed in a <form> element. You do not need to worry about where and how that form is submitted; however, you '''must''' provide a way to submit it (i.e., an <input type="submit" />.
You should return a boolean value denoting the success or failure of your method's actions.
** <div class="function_title">config_save</div>

function config_save($data) {
// Default behavior: save all variables as $CFG properties
// You don't need to override this if you 're satisfied with the above
foreach ($data as $name => $value) {
set_config($name, $value);
}
return true;
}
This method allows you to override the storage mechanism for your global configuration data. The received argument is an associative array, with the keys being setting names and the values being setting values. The default implementation saves everything as Moodle $CFG variables.
Note that $data does not hold all of the submitted POST data because Moodle adds some hidden fields to the form in order to be able to process it. However, before calling this method it strips the hidden fields from the received data and so when this method is called only the "real" configuration data remain.
You should return a boolean value denoting the success or failure of your method's actions.
** <div class="function_title">get_content</div>

function get_content() {
// This should be implemented by the derived class.
return NULL;
}
This method should, when called, populate the [[Blocks_Howto#variable_content| $this->content]] variable of your block. Populating the variable means:
'''EITHER'''<br />defining $this->content->text and $this->content->footer if your block derives from '''block_base'''. Both of these should be strings, and can contain arbitrary HTML.
'''OR'''<br />defining $this->content->items, $this->content->icons and $this->content->footer if your block derives from '''block_list'''. The first two should be numerically indexed arrays having the exact same number of elements. $this->content->items is an array of strings that can contain arbitrary HTML while $this->content->icons also contains should strings, but those must be fully-qualified HTML <img> tags '''and nothing else'''. $this->content->footer is a string, as above.
If you set ''all'' of these variables to their default "empty" values (empty arrays for the arrays and empty strings for the strings), the block will '''not''' be displayed at all except to editing users. This is a good way of having your block hide itself to unclutter the screen if there is no reason to have it displayed.
Before starting to populate [[Blocks_Howto#variable_content| $this->content]], you should also include a simple caching check. If [[Blocks_Howto#variable_content| $this->content]] is exactly equal to NULL then proceed as normally, while if it is not, return the existing value instead of calculating it once more. If you fail to do this, Moodle will suffer a performance hit.
In any case, your method should return the fully constructed [[Blocks_Howto#variable_content| $this->content]] variable.
** <div class="function_title">has_config</div>

function has_config() {
return false;
}
This method should return a boolean value that denotes whether your block wants to present a configuration interface to site admins or not. The configuration that this interface offers will impact all instances of the block equally.
To actually implement the configuration interface, you will either need to rely on the default [[Blocks_Howto#method_instance_config_print| config_print]] method or override it. The full guide contains [[Blocks_Howto#section_effects_of_globalization| more information on this]].
** <div class="function_title">hide_header</div>

function hide_header() {
//Default, false--> the header is shown
return false;
}
This method should return a boolean value that denotes whether your block wants to hide its header (or title). Thus, if you override it to return true, your block will not display a title unless the current user is in editing mode.
** <div class="function_title">html_attributes</div>

function html_attributes() {
// Default case: an id with the instance and a class with our name in it
return array('id' => 'inst'.$this->instance->id, 'class' => 'block_'. $this->name());
}
This method should return an associative array of HTML attributes that will be given to your block's container element when Moodle constructs the output HTML. No sanitization will be performed in these elements at all.
If you intend to override this method, you should return the default attributes as well as those you add yourself. The recommended way to do this is:

function html_attributes() {
$attrs = parent::html_attributes();
// Add your own attributes here, e.g.
// $attrs['width'] = '50%';
return $attrs;
}
** <div class="function_title">init</div>

function init() {
$this->title = get_string('simplehtml', 'block_simplehtml');
$this->version = 2004111200;
}
This method must be implemented for all blocks. It has to assign meaningful values to the object variables [[Blocks_Howto#variable_title| $this->title]] and [[Blocks_Howto#variable_version| $this->version]] (which is used by Moodle for performing automatic updates when available).
No return value is expected from this method.
** <div class="function_title">instance_allow_config</div>

function instance_allow_config() {
return false;
}
This method should return a boolean value. True indicates that your block wants to have per-instance configuration, while false means it does not. If you do want to implement instance configuration, you will need to take some additional steps apart from overriding this method; refer to the full guide for [[Blocks_Howto#section_configure_that_out| more information]].
This method's return value is irrelevant if [[Blocks_Howto#method_instance_allow_multiple| instance_allow_multiple]] returns true; it is assumed that if you want multiple instances then each instance needs its own configuration.
** <div class="function_title">instance_allow_multiple</div>

function instance_allow_multiple() {
// Are you going to allow multiple instances of each block?
// If yes, then it is assumed that the block WILL USE per-instance configuration
return false;
}
This method should return a boolean value, indicating whether you want to allow multiple instances of this block in the same page or not. If you do allow multiple instances, it is assumed that you will also be providing per-instance configuration for the block. Thus, you will need to take some additional steps apart from overriding this method; refer to the full guide for [[Blocks_Howto#section_configure_that_out| more information]].
** <div class="function_title">instance_config_print</div>
<nowiki>
function instance_config_print() {
// Default behavior: print the config_instance.html file
// You don't need to override this if you're satisfied with the above
if (!$this->instance_allow_multiple() && !$this->instance_allow_config()) {
return false;
}
global $CFG, $THEME;

if (is_file($CFG->dirroot .'/blocks/'. $this->name() .'/config_instance.html')) {
print_simple_box_start('center', '', $THEME->cellheading);
include($CFG->dirroot .'/blocks/'. $this->name() .'/config_instance.html');
print_simple_box_end();
} else {
notice(get_string('blockconfigbad'),
str_replace('blockaction=', 'dummy=', qualified_me()));
}

return true;
}</nowiki>
This method allows you to choose how to display the instance configuration screen for your block. Override it if you need something much more complex than the default implementation allows you to do. Keep in mind that whatever you do output from [[Blocks_Howto#method_instance_config_print| config_print]], it will be enclosed in a HTML form automatically. You only need to provide a way to submit that form.
You should return a boolean value denoting the success or failure of your method's actions.
** <div class="function_title">instance_config_save</div>

function instance_config_save($data) {
$data = stripslashes_recursive($data);
$this->config = $data;
return set_field('block_instance', 'configdata', base64_encode(serialize($data)),
'id', $this->instance->id);
}
This method allows you to override the storage mechanism for your instance configuration data. The received argument is an associative array, with the keys being setting names and the values being setting values.
The configuration must be stored in the "configdata" field of your instance record in the database so that Moodle can auto-load it when your block is constructed. However, you may still want to override this method if you need to take some additional action apart from saving the data. In that case, you really should do what data processing you want and then call parent::instance_config_save($data) with your new $data array. This will keep your block from becoming broken if the default implementation of instance_config_save changes in the future.
Note that $data does not hold all of the submitted POST data because Moodle adds some hidden fields to the form in order to be able to process it. However, before calling this method it strips the hidden fields from the received data and so when this method is called only the "real" configuration data remain.
If you want to update the stored copy of the configuration data at run time (for example to persist some changes you made programmatically), you should not use this method. The correct procedure for that purpose is to call [[Blocks_Howto#method_instance_config_commit| instance_config_commit]].
You should return a boolean value denoting the success or failure of your method's actions.
** <div class="function_title">preferred_width</div>

function preferred_width() {
// Default case: the block wants to be 180 pixels wide
return 180;
}
This method should return an integer value, which is the number of pixels of width your block wants to take up when displayed. Moodle will try to honor your request, but this is actually up to the implementation of the format of the page your block is being displayed in and therefore no guarantee is given. You might get exactly what you want or any other width the format decides to give you, although obviously an effort to accomodate your block will be made.
Most display logic at this point allocates the maximum width requested by the blocks that are going to be displayed, bounding it both downwards and upwards to avoid having a bad-behaving block break the format.
** <div class="function_title">refresh_content</div>

function refresh_content() {
// Nothing special here, depends on content()
$this->content = NULL;
return $this->get_content();
}
This method should cause your block to recalculate its content immediately. If you follow the guidelines for [[Blocks_Howto#get_content| get_content]], which say to respect the current content value unless it is NULL, then the default implementation will do the job just fine.
You should return the new value of [[Blocks_Howto#variable_content| $this->content]] after refreshing it.
** <div class="function_title">specialization</div>

function specialization() {
// Just to make sure that this method exists.
}
This method is automatically called by the framework immediately after your instance data (which includes the page type and id and all instance configuration data) is loaded from the database. If there is some action that you need to take as soon as this data becomes available and which cannot be taken earlier, you should override this method.
The instance data will be available in the variables [[Blocks_Howto#variable_instance| $this->instance]] and [[Blocks_Howto#variable_config| $this->config]].
This method should not return anything at all.
=== Methods which you should ''not'' override but may want to use: ===
** <div class="function_title">instance_config_commit</div>

function instance_config_commit() {
return set_field('block_instance',
'configdata', base64_encode(serialize($this->config)),
'id', $this->instance->id);
}
This method saves the current contents of [[Blocks_Howto#variable_config| $this->config]] to the database. If you need to make a change to the configuration settings of a block instance at run time (and not through the usual avenue of letting the user change it), just make the changes you want to [[Blocks_Howto#variable_config| $this->config]] and then call this method.
** <div class="function_title">get_content_type</div>

function get_content_type() {
return $this->content_type;
}
This method returns the value of [[Blocks_Howto#variable_content_type| $this->content_type]], and is the preferred way of accessing that variable. It is guaranteed to always work, now and forever. Directly accessing the variable is '''not recommended'''<nowiki>; future library changes may break compatibility with code that does so.</nowiki>
** <div class="function_title">get_title</div>

function get_title() {
return $this->title;
}
This method returns the value of [[Blocks_Howto#variable_title| $this->title]], and is the preferred way of accessing that variable. It is guaranteed to always work, now and forever. Directly accessing the variable is '''not recommended'''<nowiki>; future library changes may break compatibility with code that does so.</nowiki>
** <div class="function_title">get_version</div>

function get_version() {
return $this->version;
}
This method returns the value of [[Blocks_Howto#variable_version| $this->version]], and is the preferred way of accessing that variable. It is guaranteed to always work, now and forever. Directly accessing the variable is '''not recommended'''<nowiki>; future library changes may break compatibility with code that does so.</nowiki>
** <div class="function_title">is_empty</div>
For blocks that extend class '''block_base'''<nowiki>:</nowiki>

function is_empty() {
$this->get_content();
return(empty($this->content->text) && empty($this->content->footer));
}
For blocks that extend class '''block_list'''<nowiki>:</nowiki>

function is_empty() {
$this->get_content();
return (empty($this->content->items) && empty($this->content->footer));
}
This method returns the a boolean true/false value, depending on whether the block has any content at all to display. Blocks without content are not displayed by the framework.
** <div class="function_title">name</div>

function name() {
static $myname;
if ($myname === NULL) {
$myname = strtolower(get_class($this));
$myname = substr($myname, strpos($myname, '_') + 1);
}
return $myname;
}
This method returns the internal name of your block inside Moodle, without the '''block_''' prefix. Obtaining the name of a block object is sometimes useful because it can be used to write code that is agnostic to the actual block's name (and thus more generic and reusable). For an example of this technique, see the [[Blocks_Howto#method_config_print| config_print]] method.
=== Methods which you should ''not'' override and ''not'' use at all: ===
** <div class="function_title">_self_test</div>
This is a private method; no description is given.
** <div class="function_title">_add_edit_controls</div>
This is a private method; no description is given.
** <div class="function_title">_load_instance</div>
This is a private method; no description is given.
** <div class="function_title">_print_block</div>
This is a private method; no description is given.
** <div class="function_title">_print_shadow</div>
This is a private method; no description is given.

The class '''block_base''' also has a few standard member variables which its methods manipulate. These variables, the purpose of each and the type of data they are expected to hold is explained in the next section of this Appendix.

=== Class variables: ===

* <div class="variable_title">$this->config</div>
This variable holds all the specialized instance configuration data that have been provided for this specific block instance (object). It is an object of type stdClass, with member variables directly corresponding to the HTML <input> elements in the block's <span class="filename">config_instance.html</span> file.
The variable is initialized just after the block object is constructed, immediately before [[Blocks_Howto#method_specialization| specialization]] is called for the object. It is possible that the block has no instance configuration, in which case the variable will be NULL.
It is obvious that there is a direct relationship between this variable and the configdata field in the mdl_block_instance table. However, it is ''strongly'' advised that you refrain from accessing the configdata field yourself. If you absolutely must update its value at any time, it is recommended that you call the method [[Blocks_Howto#method_instance_config_commit| instance_config_commit]] to do the actual work.
* <div class="variable_title">$this->content_type</div>
This variable instructs Moodle on what type of content it should assume the block has, and is used to differentiate text blocks from list blocks. It is essential that it has a meaningful value, as Moodle depends on this for correctly displaying the block on screen. Consequently, this variable is closely tied with the variable [[Blocks_Howto#variable_content| $this->content]]. The variable is expected to have a valid value after the framework calls the [[Blocks_Howto#method_init| init]] method for each block.
The only valid values for this variable are the two named constants [[Blocks_Howto#constant_block_type_text| BLOCK_TYPE_TEXT]] and [[Blocks_Howto#constant_block_type_list| BLOCK_TYPE_LIST]].
* <div class="variable_title">$this->content</div>
This variable holds all the actual content that is displayed inside each block. Valid values for it are either NULL or an object of class stdClass, which must have specific member variables set as explained below. Normally, it begins life with a value of NULL and it becomes fully constructed (i.e., an object) when [[Blocks_Howto#method_get_content| get_content]] is called.
After it is fully constructed, this object is expected to have certain properties, depending on the value of [[Blocks_Howto#variable_content_type| $this->content_type]]. Specifically:
** If [[Blocks_Howto#variable_content_type| $this->content_type]] is [[Blocks_Howto#constant_block_type_text| BLOCK_TYPE_TEXT]], then [[Blocks_Howto#variable_content| $this->content]] is expected to have the following member variables:
*** <div>'''text'''</div>This is a string of arbitrary length and content. It is displayed inside the main area of the block, and can contain HTML.
*** <div>'''footer'''</div>This is a string of arbitrary length and contents. It is displayed below the text, using a smaller font size. It can also contain HTML.
** If [[Blocks_Howto#variable_content_type| $this->content_type]] is [[Blocks_Howto#constant_block_type_list| BLOCK_TYPE_LIST]], then [[Blocks_Howto#variable_content| $this->content]] is expected to have the following member variables:
*** <div>'''items'''</div>This is a numerically indexed array of strings which holds the title for each item in the list that will be displayed in the block's area. Since usually such lists function like menus, the title for each item is normally a fully qualified HTML <a> tag.
*** <div>'''icons'''</div>This is a numerically indexed array of strings which represent the images displayed before each item of the list. It therefore follows that it should have the exact number of elements as the items member variable. Each item in this array should be a fully qualified HTML <img> tag.
*** <div>'''footer'''</div>This is a string of arbitrary length and contents. It is displayed below the text, using a smaller font size. It can also contain HTML.
* <div class="variable_title">$this->instance</div>
This member variable holds all the specific information that differentiates one block instance (i.e., the PHP object that embodies it) from another. It is an object of type stdClass retrieved by calling get_record on the table mdl_block_instance. Its member variables, then, directly correspond to the fields of that table. It is initialized immediately after the block object itself is constructed.
* <div class="variable_title">$this->title</div>
This variable is a string that contains the human-readable name of the block. It is used to refer to blocks of that type throughout Moodle, for example in the administrator's block configuration screen and in the editing teacher's add block menu. It is also the title that is printed when the block is displayed on screen, although blocks can specifically change this title to something else if they wish (see below). The variable is expected to have a valid value after the framework calls the [[Blocks_Howto#method_init| init]] method for each object.
In the case of blocks which may want to configure their title dynamically through instance configuration, it is still essential to provide a valid title inside [[Blocks_Howto#method_init| init]]. This title may then be overridden when the [[Blocks_Howto#method_specialization| specialization]] method is called by the framework:

function specialization() {
// At this point, $this->instance and $this->config are available
// for use. We can now change the title to whatever we want.
$this->title = $this->config->variable_holding_the_title;
}
* <div class="variable_title">$this->version</div>
This variable should hold each block's version number in the form '''YYYYMMDDXX''', as per the convention throughout Moodle. The version number is used by Moodle to detect when a block has been upgraded and it consequently needs to run the block's upgrade code to bring the "old" version of the block's data up to date. The variable is expected to have a valid value after the framework calls the [[Blocks_Howto#method_init| init]] method for each block.
Most blocks do not keep complex data of their own in the database the way that modules do, so in most cases nothing actually happens during a block version upgrade. However, the version number is displayed in the administration interface for blocks. It is good practice therefore to change your block's version number when it gains new functionality or receives important bug fixes, to enable site administrators to easily identify the exact version of the block they are working with.

Appearing throughout the code related to the Blocks API, there is a number of predefined constants that are utilized to avoid the use of "magic numbers" in the code. These constants are:

=== Named constants: ===

* <div class="named_constant">BLOCK_TYPE_LIST</div>
This is one of the two valid values for the [[Blocks_Howto#variable_content_type| $this->content_type]] member variable of every block. Its value specifies the exact requirements that Moodle will then have for [[Blocks_Howto#variable_content| $this->content]].
* <div class="named_constant">BLOCK_TYPE_TEXT</div>
This is one of the two valid values for the [[Blocks_Howto#variable_content_type| $this->content_type]] member variable of every block. Its value specifies the exact requirements that Moodle will then have for [[Blocks_Howto#variable_content| $this->content]].

== Appendix B: Differences in the Blocks API for Moodle versions prior to 1.5 ==

This Appendix will discuss what changes in the Blocks API were introduced by Moodle 1.5 and what steps developers need to take to update their blocks to be fully compatible with Moodle 1.5. Unfortunately, with these changes backward compatibility is broken; this means that blocks from Moodle 1.4 will never work with 1.5 and vice versa.

=== Class naming conventions changed ===
In Moodle 1.4, all block classes were required to have a name like '''CourseBlock_something''' and the base class from which the derived was '''MoodleBlock'''. This has changed in Moodle 1.5, to bring the naming conventions in line with other object-oriented aspects of Moodle (for example there are classes enrolment_base, resource_base etc). The new block classes should instead be named like '''block_something''' and derive from '''block_base'''. This means that in order to make a block compatible with Moodle 1.5, you need to change the class definition

class CourseBlock_online_users extends MoodleBlock { ... }
to

class block_online_users extends block_base { ... }
An exception to the above is the special case where the block is intended to display a list of items instead of arbitrary text; in this case the block class must derive from class '''block_list''' instead, like this:

class block_admin extends block_list { ... }

=== Constructor versus init() ===

In Moodle 1.4, in each block class it was mandatory to define a constructor which accepted a course data record as an argument (the example is from the actual Online Users block):

function CourseBlock_online_users ($course) {
$this->title = get_string('blockname','block_online_users');
$this->content_type = BLOCK_TYPE_TEXT;
$this->course = $course;
$this->version = 2004052700;
}
In contrast, Moodle 1.5 does away with the constructor and instead requires you to define an init() method that takes no arguments:

function init() {
$this->title = get_string('blockname','block_online_users');
$this->version = 2004111600;
}
Of course, this leaves you without access to the $course object, which you might actually need. Since that's probably going to be needed inside [[Blocks_Howto#method_get_content| get_content]], the way to retrieve it is by using this code:

$course = get_record('course', 'id', $this->instance->pageid);
If you are going to need access to $course from inside other methods in addition to [[Blocks_Howto#method_get_content| get_content]], you might fetch the $course object inside the [[Blocks_Howto#method_specialization| specialization]] method and save it as a class variable for later use, in order to avoid executing the same query multiple times:

function specialization() {
$this->course = get_record('course', 'id', $this->instance->pageid);
}

=== Blocks with configuration ===
In Moodle 1.4, blocks could only have what are now (in Moodle 1.5) called "global configuration" options, to differentiate from the new "instance configuration" options. If your block has support for configuration, you will need to take these steps:
## Rename your <span class="filename">config.html</span> file to <span class="filename">config_global.html</span>.
## Edit the newly renamed file and completely remove the <form> tag (Moodle now wraps your configuration in a form automatically).
## If you are using any HTML <input> tags other than those that directly affect your configuration (for example, "sesskey"), REMOVE those too (Moodle will add them automatically as required).
## If you have overridden '''print_config''', rename your method to '''config_print'''.
## If you have overridden '''handle_config''', rename your method to '''config_save'''.
=== Blocks with customized applicable formats ===
The correct way to specify the formats you want to allow or disallow your block to exist has been reworked for Moodle 1.5 to take account of the fact that blocks are no longer restricted to just courses. To have a block retain its intended behavior, you must change these format names (array keys in the return value of [[Blocks_Howto#method_applicable_formats| applicable_formats]]) if they are used in your block:
#* '''social''' should become '''course-view-social'''
#* '''topics''' should become '''course-view-topics'''
#* '''weeks''' should become '''course-view-weeks'''
You should also keep in mind that there is now the possibility of blocks being displayed in other pages too, like the introductory page that users see when they enter an activity module. You might therefore need to make the specification for applicable formats more restrictive to keep your block out of pages it is not supposed to be shown in. Also, there are subtle changes to the way that the final decision to allow or disallow a block is made. For the technical details refer to the definition of [[Blocks_Howto#method_applicable_formats| applicable_formats]], and for a more extended example read [[Blocks_Howto#section_authorized_personnel_only| the section dedicated to this subject]].
That's everything; your block will now be ready for use in Moodle 1.5!

[[Category:Developer]]

[[es:Desarrollo de bloques]]