MoodleDocs - User contributions [en]

Migrating log access in reports

2014-07-17T22:45:08Z

Ravenink:

This document is aimed to assist developers in replacing SQL queries that access the '''log''' table (now referred to as the "legacy log" for reports or other plugins.

A new [[Logging 2|logging system]] is being introduced in Moodle 2.7. Writing to the legacy logging table may still be supported on some systems, however it is intended that administrators will make use of other logging plugins that can write to DB tables in the same DB as Moodle, to external DBs (SQL or non-SQL), to files, and so on. By default, a '''logstore_standard''' plugin is enabled that writes the data in the internal DB table. This table should not be queried directly. The new logging plugins define interfaces for reading data from the log stores.

Reports also have the choice of accessing the active log stores via logging plugin reader interfaces or registering their own observers and storing necessary data themselves.

== Using log readers ==

First, reports need to find available log readers.

There are three interfaces defined in core that log storage plugins may implement.
* '''\core\log\reader''' - parent for all reader interfaces;
* '''\core\log\sql_select_reader''' - has methods to create simple SQL queries to the log store. The table (or equivalent storage collection) used is expected to have columns that correspond to properties of class '''\core\base\event''' and
* '''\core\log\sql_internal_reader''' - additionally has a method to return the table name which can be used to JOIN queries.

The report decides which type of readers it can work with. Assuming we need a select reader, the following example will access available interfaces of this type.
<pre>
$manager = get_log_manager();
$selectreaders = $manager->get_readers('\core\log\sql_select_reader');
if ($selectreaders) {
$reader = reset($selectreaders);
} else {
// No available log reader found.
}
</pre>

The method \core\log\manager::get_readers() returns an associative array of singleton instances of enabled log store plugins implementing the reader interface. When a plugin finds the necessary log reader it can query the data from it. Refer to the interfaces for the list of methods they implement.

For a transition period, a site may support both legacy logging and the new standard logging plugin. A report might need to access both log storages especially if it needs information that covers a long period of time that includes the transition from the legacy log to the new standard log. Please note that columns and event names are different in the new logging system and the legacy log, so separate queries will be needed.

Here is an example of how to use the legacy log reader (which may be present but not enabled for writing).
<pre>
$manager = get_log_manager();
$allreaders = $manager->get_readers();
if (isset($allreaders['logstore_legacy'])) {
$legacyreader = $allreaders['logstore_legacy'];
if ($legacyreader->is_logging()) {
// All events continue to be recorded in {log} table.
} else {
// The {log} table is kept for storing the old logs only. New events are not written to it and must be taken from another log storage.
}
} else {
// You are probably developing for 2.10 and table {log} does not exist any more. Or administrator uninstalled the plugin.
}
</pre>

== Registering an observer ==

Accessing logs on large Moodle instances will be slow and will cause load on the entire system. Some reports may wish to create their own mini log storages, storing only relevant events and perhaps only for a limited time. If you anticipate that such tables will be small, this can be an alternative solution to reading from logs.

In order to implement an observer in a plugin you must:
* define a database table in PLUGINDIR/db/install.xml and create it in PLUGINDIR/db/upgrade.php;
* define event observers in PLUGINDIR/db/events.php with handler functions (see [[Event_2#Event_observers|Events 2]]);
* define a cron task that truncates the old entries from the table when they are no longer needed (define $plugin->cron in your version.php);
* possibly create an upgrade script (in PLUGINDIR/db/upgrade.php) that migrates any relevant events from the legacy log table into the new observer table and
* re-write the SQL queries inside the plugin to access the new observer table instead of logs.

lib/formslib.php Form Definition

2012-07-26T08:00:09Z

Ravenink:

{{Formslib}}
== ''definition()'' ==

The definition of the elements to be included in the form, their 'types' (PARAM_*), helpbuttons included, etc. is all included in a function you must define in your class.

''definition()'' is used to define the elements in the form and '''this definition will be used for validating data submitted as well as for printing the form.''' For select and checkbox type elements only data that could have been selected will be allowed. And only data that corresponds to a form element in the definition will be accepted as submitted data.

The ''definition()'' should include all elements that are going to be used on form, some elements may be removed or tweaked later in ''definition_after_data()''. Please do not create conditional elements in ''definition()'', the definition() should not directly depend on the submitted data.

Note that the definition function is called when the form class is instantiated. There is no option to (say) manipulate data in the class (that may affect the rendering of the form) between instantiating the form and calling any other methods.

<code php>
require_once("$CFG->libdir/formslib.php");

class simplehtml_form extends moodleform {

function definition() {
global $CFG;

$mform =& $this->_form; // Don't forget the underscore!

$mform->addElement()... // Add elements to your form
...
} // Close the function
} // Close the class
</code>
===Passing parameters to the Form===

The constructor for ''moodleform'' allows a number of parameters including one (''$customdata'') to permit an array of arbitrary data to be passed to your form.

For example, you can pass the data "$email" and "$username" to the Form's class for use inside (say) the definition.
<code php>
...
$mform_simple = new simplehtml_form( null, array('email'=>$email, 'username'=>$username ) );
...
</code>
(the first parameter is $action, ''null'' will case the form action to be determined automatically)

Secondly, inside the form definition you can use those parameters to set the default values to some of the form's fields
<code php>
...
$mform->addElement('text', 'email', get_string('email'), 'maxlength="100" size="25" ');
$mform->setType('email', PARAM_NOTAGS);
$mform->addRule('email', get_string('missingemail'), 'required', null, 'server');
// Set default value by using a passed parameter
$mform->setDefault('email',$this->_customdata['email']);
...
</code>

==Use Fieldsets to group Form Elements==

You use code like this to open a fieldset with a ''legend''. <br />
('''Note''': Some themes turn off legends on admin setting pages by using CSS: <nowiki>#adminsettings legend {display:none;}</nowiki>.)

<code php>
$mform->addElement('header', 'nameforyourheaderelement', get_string('titleforlegened', 'modulename'));
</code>

You can't yet nest these visible fieldsets unfortunately. But in fact groups of elements are wrapped in invisible fieldsets.

You close a fieldset with moodle_form's closeHeaderBefore method. You tell closeHeaderBefore the element before you wish to end the fieldset. A fieldset is automatically closed if you open a new one. You need to use this code only if you want to close a fieldset and the subsequent form elements are not to be enclosed by a visible fieldset (they are still enclosed with an invisibe one with no legend) :

<code php>
$mform->closeHeaderBefore('buttonar');
</code>

==addElement==

Use the addElement method to add an element to a form. The first few arguments are always the same. The first param is the type of the element to add. The second is the elementname to use which is normally the html name of the element in the form. The third is often the text for the label for the element.

Some examples are below :
=== button ===

<code php>
$mform->addElement('button', 'intro', get_string("buttonlabel"));
</code>

A button element. If you want a submit or cancel button see 'submit' element.

=== checkbox ===

<code php>
$mform->addElement('checkbox', 'ratingtime', get_string('ratingtime', 'forum'));
</code>

This is a simple checkbox. The third parameter for this element is the label to display on the left side of the form. You can also supply a string as a fourth parameter to specify a label that will appear on the right of the element. Checkboxes and radio buttons can be grouped and have individual labels on their right.

You can have a 5th parameter $attributes, as on other elements.

'''BEWARE:''' Unchecked checkboxes return nothing at all (as if they didn't exist). This can surprise the unwary. You may wish to use advcheckbox instead, which does return a value when not checked. 'Advcheckbox' eliminates this problem.

==== advcheckbox ====
<code php>
$mform->addElement('advcheckbox', 'ratingtime', get_string('ratingtime', 'forum'), 'Label displayed after checkbox', array('group' => 1), array(0, 1));
</code>

Similar to the checkbox above, but with some important improvements:

# The (optional) 5th parameter is a normal $attributes array, normally used to set HTML attributes for the <input> element. However, a special value of 'group' can be given, which will add a class name to the element, and enable its grouping for a [[lib/formslib.php_add_checkbox_controller|checkbox controller]]
#The (optional) 6th parameter is an array of values that will be associated with the checked/unchecked state of the checkbox. With a normal checkbox you cannot choose that value, and in fact an unchecked checkbox will not even be sent with the form data.
#It returns a 0 value when unchecked. Compare with the ordinary checkbox which does not return anything at all.

=== choosecoursefile ===
{{Moodle 1.9}}
<code php>
$mform->addElement('choosecoursefile', 'mediafile', get_string('mediafile', 'lesson'), array('courseid'=>$COURSE->id));
</code>

Choose a file from the course files area. The fourth option is a list of options for the element.

'''Note: This has been superceded by [[#filepicker|filepicker]] in Moodle 2.'''

<code php>
array('courseid' =>null, //if it is null (default then use global $COURSE
'height' =>500, // height of the popup window
'width' =>750, // width of the popup window
'options' =>'none'); //options string for the pop up window
//eg. 'menubar=0,location=0,scrollbars,resizable'
</code>

You can also pass an optional 5th parameter of attributes, as for other elements. The most useful way of using that is something like
<code php>array('maxlength' => 255, 'size' => 48)</code>
to control the maxlength / size of the text box (note size will default to 48 if not specified)

Finally, as this element is a group containing two elements (button + value), you can add validation rules by using the '''addGroupRule()''' method in this (complex) way:

<code php>$mform->addGroupRule('elementname', array('value' => array(array(list, of, rule, params, but, fieldname))));</code>

Where: '''"elementname"''' is the name of the choosecoursefile group element, '''"value"''' is the name of the text field within the group and the '''"list, of, addrule, params, but, fieldname"''' is exactly that, the list of fields in the normal addRule() function but ommiting the first one, the fieldname.

For example, the [http://cvs.moodle.org/moodle/mod/resource/type/file/resource.class.php?view=markup file/url resource type], uses one "choosecoursefile" element, and it controls the maximum length of the field (255) with this use of addGroupRule():

<code php>$mform->addGroupRule('reference', array('value' => array(array(get_string('maximumchars', '', 255), 'maxlength', 255, 'client'))));</code>

=== date_selector ===

<code php>
$mform->addElement('date_selector', 'assesstimefinish', get_string('to'));
</code>

This is a date selector. You can select a Day, Month and Year using a group of select boxes. The fourth param here is an array of options. The defaults for the options are :

<code php>
array(
'startyear' => 1970,
'stopyear' => 2020,
'timezone' => 99,
'optional' => false
);
</code>

You can override these defaults by supplying an array as fourth param with one or more keys with a value to override the default. You can supply a fifth param of attributes here as well.

=== date_time_selector ===

<code php>
$mform->addElement('date_time_selector', 'assesstimestart', get_string('from'));
</code>

This is a group of select boxes to select a date (Day Month and Year) and time (Hour and Minute). When submitted, submitted data is processed and a timestamp is passed to $form->get_data(); the fourth param here is an array of options. The defaults for the options are:

<code php>
array(
'startyear' => 1970,
'stopyear' => 2020,
'timezone' => 99,
'step' => 5
);
</code>

You can override these defaults by supplying an array as fourth param with one or more keys with a value to override the default. You can supply a fifth param of attributes here as well.

===duration===
{{Moodle 2.0}}

<code php>
$mform->addElement('duration', 'timelimit', get_string('timelimit', 'quiz'));
</code>
This field type lets the user input an interval of time. It comprises a text field, where you can type a number, and a dropdown for selecting a unit (days, hours, minutes or seconds). When submitted the value is converted to a number of seconds.

You can add a fourth parameter to give options. At the moment the only option supported is here is an array of options. The defaults for the options is:
<code php>array('optional' => true)</code>

You can also pass an optional 5th parameter of attributes, as for other elements. The most useful way of using that is something like
<code php>array('size' => 5)</code>
to control the size of the text box.

=== editor ===

This replaces the old htmleditor field type. It allows the user to enter rich text content in a variety of formats.

<code php>
$mform->addElement('editor', 'fieldname', get_string('labeltext', 'langfile'));
$mform->setType('fieldname', PARAM_RAW);
</code>

If you would like to let the user use the filepicker to upload images etc. that are used in the content, then see [[Using_the_File_API_in_Moodle_forms]].

You can supply a fourth param to htmleditor of an array of options that are mostly related to file handling:

<code php>
array(
'subdirs'=>0,
'maxbytes'=>0,
'maxfiles'=>0,
'changeformat'=>0,
'context'=>null,
'noclean'=>0,
'trusttext'=>0);
</code>

=== file ===

File upload input box with browse button. In the form definition type

<code php>
$mform->addElement('file', 'attachment', get_string('attachment', 'forum'));
</code>

after form submission and validation use

<code php>
if ($data = $mform->get_data()) {
...
$mform->save_files($destination_directory);
...
}
</code>

If there is no requirement to save the file, you can read the file contents directly into a string as follows...

<code php>
$mform->get_file_content('attachment');
</code>

If you need advanced settings such as required file, different max upload size or name of uploaded file

<code php>
$this->set_upload_manager(new upload_manager('attachment', true, false, $COURSE, false, 0, true, true, false));
$mform->addElement('file', 'attachment', get_string('attachment', 'forum'));
$mform->addRule('attachment', null, 'required');

</code>

<code php>
if ($data = $mform->get_data()) {
...
$mform->save_files($destination_directory);
$newfilename = $mform->get_new_filename();
...
}
</code>

When porting old code it is also possible to use the upload manager directly for processing of uploaded files.

Please note that if using set_upload_manager() it must be before addElement('file',..).

{{Moodle 2.0}}
File uploading was rewritten in 2.0. Please see inline docs for now. This page will be updated when the new API stabilises.

===filepicker===
{{Moodle 2.0}}
General replacement of ''file'' element.

<code php>
$mform->addElement('filepicker', 'userfile', get_string('file'), null, array('maxbytes' => $maxbytes, 'accepted_types' => '*'));
</code>
See also [[Using the File API in Moodle forms]]

=== hidden ===
<code php>
$mform->addElement('hidden', 'reply', 'yes');
</code>

A hidden element. Set the element name (in this case '''reply''') to the stated value (in this case '''yes''').

=== html ===
You can add arbitrary HTML to your Moodle form:

<code php>
$mform->addElement('html', '<div class="qheader">');
</code>

See [http://moodle.org/mod/forum/discuss.php?d=126935 "Question: Can I put a moodleform inside a table td?"] for a concrete example.

=== htmleditor & format ===

These elements are now deprecated. Please use the [[#editor|editor]] field type instead.

===modgrade===
<pre>
$mform->addElement('modgrade', 'scale', get_string('grade'), false);
</pre>
This is a custom element for selecting a grade for any activity module. The fourth argument is whether to include an option for no grade which has a value 0. This select box does include scales. The default is true, include no grade option.

A helpbutton is automatically added.

===modvisible===
<pre>
$mform->addElement('modvisible', 'visible', get_string('visible'));
</pre>
This is a custom element for selecting a grade visibility in an activity mod update form.

===password===
<pre>
$mform->addElement('password', 'password', get_string('label'), $attributes);
</pre>

A password element. Fourth param is an array or string of attributes.

===passwordunmask===
{{Moodle 1.9}}
<pre>
$mform->addElement('passwordunmask', 'password', get_string('label'), $attributes);
</pre>

A password element with option to show the password in plaintext. Fourth param is an array or string of attributes.

=== radio ===
{{Moodle 2.3}}
<code php>
$radioarray=array();
$radioarray[] =& $mform->createElement('radio', 'yesno', '', get_string('yes'), 1, $attributes);
$radioarray[] =& $mform->createElement('radio', 'yesno', '', get_string('no'), 0, $attributes);
$mform->addGroup($radioarray, 'radioar', '', array(' '), false);
</code>

Second param names the radio button and should be the same for each button in the group in order to toggle correctly. Third param would be the label for the form element but is generally ignored as this element will always be in a group which has it's own label. Fourth param is a string, a label to be displayed on the right of the element. The fifth is the value for this radio button. $attributes can be a string or an array of attributes.

It is possible to add help to individual radio buttons but this requires a custom template to be defined for the group elements. See MDL-15571.

Since 2.3 it cannot be statically called anymore, so we need to call createElement from $mform reference.

==== setDefault ====

To set the default for a radio button group as above use the following :

<code php>
$mform->setDefault('yesno', 0);
</code>

This would make the default 'no'.

===select===
<pre>
$mform->addElement('select', 'type', get_string('forumtype', 'forum'), $FORUM_TYPES, $attributes);
</pre>

The fourth param for this element is an array of options for the select box. The keys are the values for the option and the value of the array is the text for the option. The fifth param $attributes is optional, see text element for description of attributes param.

It is also possible to create a select with certain options disabled, using [http://stackoverflow.com/questions/2138089/how-can-i-use-quickform-to-add-disabled-select-options/2150275#2150275 this technique].

====multi-select====
<pre>
$select = &$mform->addElement('select', 'colors', get_string('colors'), array('red', 'blue', 'green'), $attributes);
$select->setMultiple(true);
</pre>

=====setSelected=====

To set the default selected item in a select element, you should use the 'setSelected' function, as follows:
<code>
$select = &$mform->addElement('select', 'colors', get_string('colors'), array('red', 'blue', 'green'), $attributes);
$select->setSelected('blue');
</code>
However you probably don't want to do this. Instead you probably want to use setDefault, or set it using the form's setData method.

===selectyesno===
<pre>
$mform->addElement('selectyesno', 'maxbytes', get_string('maxattachmentsize', 'forum'));
</pre>

If you want a yes / no select box this one automatically translates itself and has value 1 for yes and 0 for no.

===selectwithlink===
<pre>
$options = array();
$mform->addElement('selectwithlink', 'scaleid', get_string('scale'), $options, null,
array('link' => $CFG->wwwroot.'/grade/edit/scale/edit.php?courseid='.$COURSE->id, 'label' => get_string('scalescustomcreate')));
</pre>
select type element with options containing link
===static===
<pre>
$mform->addElement('static', 'description', get_string('description', 'exercise'),
get_string('descriptionofexercise', 'exercise', $COURSE->students));
</pre>

This is a static element. It should be used with care if it is used to display a static piece of text with a label. The third param is the label and the fourth is the static text itself.

===submit, reset and cancel===

<pre>
//normally you use add_action_buttons instead of this code
$buttonarray=array();
$buttonarray[] = &$mform->createElement('submit', 'submitbutton', get_string('savechanges'));
$buttonarray[] = &$mform->createElement('reset', 'resetbutton', get_string('revert'));
$buttonarray[] = &$mform->createElement('cancel');
$mform->addGroup($buttonarray, 'buttonar', '', array(' '), false);
$mform->closeHeaderBefore('buttonar');
</pre>

A 'Submit' type element is a submit type form element which will submit the form. A 'Reset' will not submit the form but will reset any changes the user has made to form contents. A 'Cancel' element cancels form submission. You need to have a branch in your code before you check for get_data() to check if submission has been cancelled with is_cancelled(); See the example on the usage page.

You should name your submit and reset buttons 'submitbutton' and 'resetbutton' or something similar (not 'submit' and 'reset'). This avoids problems in JavaScript of collisions between form element names and names of JavaScript methods of the form object.

====add_action_buttons($cancel = true, $submitlabel=null);====

You will normally use this helper function which is a method of moodleform to add all the 'action' buttons to the end of your form. A boolean parameter allow you to specify whether to include a cancel button and specify the label for your submit button (pass the result of get_string). Default for the submit button label is get_string('savechanges'). Note the '''$this''' not '''$mform'''

<pre>
$this->add_action_buttons();
</pre>

===text===

<pre>
$mform->addElement('text', 'name', get_string('forumname', 'forum'), $attributes);
</pre>
For a simple text element. Your fourth parameter here can be a string or array of attributes for the text element. The following are equivalent :
<pre>
$attributes='size="20"';
$attributes=array('size'=>'20');
</pre>

Generally you are encouraged to use CSS instead of using attributes for styling.

A format element can be used as a format select box. It will be non-selectable if you're using an html editor.

The third param for this element is $useHtmlEditor and it defaults to null in which case an html editor is used if the browser and user profile support it.

===textarea===

<pre>
$mform->addElement('textarea', 'introduction', get_string("introtext", "survey"), 'wrap="virtual" rows="20" cols="50"');
</pre>

A textarea element. If you want an htmleditor use htmleditor element. Fourth element here is a string or array of attributes.

===recaptcha===
{{Moodle 1.9}}
<pre>
$mform->addElement('recaptcha', 'recaptcha_field_name', $attributes);
</pre>

Use this recaptcha element to reduce the spam risk in your forms. Third element here is a string or array of attributes. Take care to get an API key from http://recaptcha.net/api/getkey before using this element.

To check whether recaptcha is enabled at site level use:
<pre>
if (!empty($CFG->recaptchapublickey) && !empty($CFG->recaptchaprivatekey)) {
//recaptcha is enabled
}
</pre>

===tags===
{{Moodle 2.0}}

<pre>
$mform->addElement('tags', 'field_name', $lable, $options, $attributes);
</pre>

Used for editing a list of tags, for example on a blog post.

There is only one option available, 'display', which should be set to one of the contstants MoodleQuickForm_tags::ONLYOFFICIAL, NOOFFICIAL or DEFAULTUI. This controls whether the official tags are listed for easy selection, or a text area where arbitrary tags may be typed, or both. The default is both.

The value should be set/returned as an array of tags.

===grading===
<code php>
$mform->addElement('grading', 'advancedgrading', get_string('grade').':', array('gradinginstance' => $gradinginstance));
</code>

Custom element for advanced grading plugins.

When adding the 'grading' element to the form, developer must pass an object of class gradingform_instance as $attributes['gradinginstance']. Otherwise an exception will be thrown.

===questioncategory===
<code php>
$mform->addElement('questioncategory', 'category', get_string('category', 'question'),
array('contexts'=>$contexts, 'top'=>true, 'currentcat'=>$currentcat, 'nochildrenof'=>$currentcat));
</code>
Creates a drop down element to select a question category.

Options are:
'''contexts''' - (required) context in which question appears
'''currentcat''' - (optional) course category
'''top''' - (optional) if true will put top categories on top
'''nochildrenof''' - (optional) Format categories into an indented list reflecting the tree structure

==addGroup==

A 'group' in formslib is just a group of elements that will have a label and will be included on one line.

For example typical code to include a submit and cancel button on the same line :

<pre>
$buttonarray=array();
$buttonarray[] =& $mform->createElement('submit', 'submitbutton', get_string('savechanges'));
$buttonarray[] =& $mform->createElement('submit', 'cancel', get_string('cancel'));
$mform->addGroup($buttonarray, 'buttonar', '', array(' '), false);
</pre>

You use the same arguments for createElement as you do for addElement. Any label for the element in the third argument is normally ignored (but not in the case of the submit buttons above where the third argument is not for a label but is the text for the button).

Here's a bad example (don't do this for real, use the 'optional' => true option of the date element): putting a date_selector (which is itself a group of elements) and a checkbox on the same line, note that you can disable every element in the group using the group name 'availablefromgroup' but it doesn't disable the controlling element the 'availablefromenabled' checkbox:

<pre>
$availablefromgroup=array();
$availablefromgroup[] =& $mform->createElement('date_selector', 'availablefrom', '');
$availablefromgroup[] =& $mform->createElement('checkbox', 'availablefromenabled', '', get_string('enable'));
$mform->addGroup($availablefromgroup, 'availablefromgroup', get_string('availablefromdate', 'data'), ' ', false);
$mform->disabledIf('availablefromgroup', 'availablefromenabled');
</pre>

==addRule==
<pre>
$mform->addRule('elementname', get_string('error'), 'rule type', 'extraruledata', 'server'(default), false, false);
</pre>

The first param(element) is an element name and second(message) is the error message that will be displayed to the user.
The third parameter(type) is the type of rule. The fourth param(format) is used for extra data needed with some rules such as minlength and regex. The fifth parameter(validation) validates input data on server or client side, if validation is done on client side then it will be checked on the server side as well.

<pre>
* @param string $element Form element name
* @param string $message Message to display for invalid data
* @param string $type Rule type, use getRegisteredRules() to get types
* @param string $format (optional)Required for extra rule data
* @param string $validation (optional)Where to perform validation: "server", "client"
* @param boolean $reset Client-side validation: reset the form element to its original value if there is an error?
* @param boolean $force Force the rule to be applied, even if the target form element does not exist
</pre>

'''Common Rule Types'''
* required
* maxlength
* minlength
* rangelength
* email
* regex
* lettersonly
* alphanumeric
* numeric
* nopunctuation
* nonzero
* callback
* compare

===Server side and Client side===
In case you use the ''Client side'' validation option, you can mainly check for an empty or not input field. unless you write some ''Client side'' code which will probably be JavaScript functions to verify the data inside the input fields before it is submitted to the server. It could save some time if those functions are short, simple and quick to compute.
In case you need a more complex validation checks which relay on Moodle's internal PHP libraries (or other/external PHP libraries) you better use the ''Server side'' validation checks. Where you can query the DB, write complex PHP validation functions and much much more, that are not available (easily) when using JavaScript on the client's side.

==setHelpButton==
{{Moodle 1.9}}

<pre>
$mform->setHelpButton('lessondefault', array('lessondefault', get_string('lessondefault', 'lesson'), 'lesson'));
</pre>
First param is an elementname and the second param is an array of params that are passed to helpbutton in weblib.php. Params are :

<pre>
* @param string $page The keyword that defines a help page
* @param string $title The title of links, rollover tips, alt tags etc
* 'Help with' (or the language equivalent) will be prefixed and '...' will be stripped.
* @param string $module Which module is the page defined in
* @param mixed $image Use a help image for the link? (true/false/"both")
* @param boolean $linktext If true, display the title next to the help icon.
* @param string $text If defined then this text is used in the page, and
* the $page variable is ignored.
* @param boolean $return If true then the output is returned as a string, if false it is printed to the current page.
* @param string $imagetext The full text for the helpbutton icon. If empty use default help.gif
</pre>
Make sure you don't set boolean $return to false.

You need to do use this method after addElement();

==addHelpButton==
{{Moodle 2.0}}

<code php>
$mform->addHelpButton('api_key_field', 'api_key', 'block_extsearch');
</code>

In Moodle 2.0 the "setHelpButton" method has been deprecated in favor of the "addHelpButton" method, which has a simplified interface and uses $OUTPUT->help_icon() on the back end. The following parameters are expected:

<code php>
/**
* @param $elementname The name of the form element to add the help button for
* @param $identifier The identifier for the help string and its title (see below)
* @param $component The component name to look for the help string in
*/
</code>
Unlike in Moodle 1.9, it is no longer necessary to put your help pages in separate HTML files. Instead, the function looks for two strings:

# get_string($identifier, $component) // The title of the help page
# get_string("{$identifier}_help", $component) // The content of the help page

So you will need to have '''$identifier''' and '''{$identifier}_help''' defined in order for the help button to be created properly. For example the multiple choice question editing form has a button for shuffling the answers.
<code php>
$mform->addHelpButton('shuffleanswers', 'shuffleanswers', 'qtype_multichoice');
</code>
and so the language file includes the strings
<code php>
$string['shuffleanswers'] = 'Shuffle the choices?';
$string['shuffleanswers_help'] = 'If enabled,.....';
</code>
You can also add the language string like
<code php>
$string['shuffleanswers_link'] = 'question/shuffleanswers';
</code>
to add a link to more help on Moodle docs. See [[String_API]] for more information about help icons.

==setDefault==

<pre>
$mform->addElement('select', 'grade', get_string('gradeforsubmission', 'exercise'), $grades);
$mform->setHelpButton('grade', array('grade', get_string('gradeforsubmission', 'exercise'), 'exercise'));
$mform->setDefault('grade', 100);
</pre>

Set the default of the form value with setDefault($elementname, $value); where elementname is the elementname whose default you want to set and $value is the default to set. We set the defaults for the form in definition(). This default is what is used if no data is loaded into the form with set_data(); eg. on display of the form for an 'add' rather than 'update' function.

==disabledIf==

For any element or groups of element in a form you can conditionally disable the group or individual element depending on conditions.

You can use $mform->disabledIf($elementName, $dependentOn, $condition = 'notchecked', $value='1')

* elementname can be a group. If you specify a group all elements in the group will be disabled (if dependentOn is in elementname group that is ignored and not disabled). These are the element names you've used as the second argument in addElement or addGroup.
* dependentOn is the actual name of the element as it will appear in html. This can be different to the name used in addGroup particularly but also addElement where you're adding a complex element like a date_selector. Check the html of your page. You typically make the depedentOn a checkbox or select box.
* $condition will be 'notchecked', 'checked', 'noitemselected', 'eq' or, if it is anything else, we test for 'neq'.
** If $condition is 'eq' or 'neq' then we check the value of the dependentOn field and check for equality (==) or nonequality (!=) in js
** If $condition is 'checked' or 'notchecked' then we check to see if a checkbox is checked or not.
** If $condition is 'noitemselected' then we check to see whether nothing is selected in a dropdown list.

Examples:
// Disable my control unless a checkbox is checked.
$mform->disabledIf('mycontrol', 'somecheckbox');

// Disable my control if a checkbox '''is''' checked.
$mform->disabledIf('mycontrol', 'somecheckbox', 'checked');

// Disable my control when a dropdown has value 42.
$mform->disabledIf('mycontrol', 'someselect', 'eq', 42);

// Disable my control unless a dropdown has value 42.
$mform->disabledIf('mycontrol', 'someselect', 'neq', 42);

The possible choices here are in the dependency manager in lib/form/form.js.

==setType==

PARAM_* types are used to specify how a submitted variable should be cleaned. These should be used for get parameters such as id, course etc. which are used to load a page and also with setType(); method. Every form element should have a type specified except select, radio box and checkbox elements, these elements do a good job of cleaning themselves (only specified options are allowed as user input).

===Most Commonly Used PARAM_* Types===

These are the most commonly used PARAM_* types and their proper uses. More types can be seen in moodlelib.php starting around line 100.

* PARAM_CLEAN is deprecated and you should try to use a more specific type.
* PARAM_TEXT should be used for cleaning data that is expected to be plain text. It will strip all html tags. But will still let tags for multilang support through.
* PARAM_NOTAGS should be used for cleaning data that is expected to be plain text. It will strip *all* html type tags. It will still *not* let tags for multilang support through. This should be used for instance for email addresses where no multilang support is appropriate.
* PARAM_RAW means no cleaning whatsoever, it is used mostly for data from the html editor. Data from the editor is later cleaned before display using format_text() function. PARAM_RAW can also be used for data that is validated by some other way or printed by p() or s().
* PARAM_INT should be used for integers.
* PARAM_ACTION is an alias of PARAM_ALPHA and is used for hidden fields specifying form actions.

==References==

* [http://www.midnighthax.com/quickform.php PEAR HTML QuickForm Getting Started Guide] by Keith Edmunds of Midnighthax.com
* [http://pear.php.net/manual/en/package.html.html-quickform.php PEAR::HTML_QuickForm manual]

[[Category:Formslib]]
[[Category:Interfaces]]

If you have problems creating php forms you may get them with form builder http://phpforms.net/tutorial/html-basics/form-builder.html

Using the File API in Moodle forms

2012-07-25T22:26:13Z

Ravenink: /* See also */

{{Moodle 2.0}}

This document shows you exactly how to use Moodle forms to get files from users in a standard and secure way.

==Overview==

In Moodle 2.0 all files are stored in a central database accessible via the [[File API|File API]], and every file is associated with a component and a "file area" in Moodle, such as a particular module.

A common use case is to provide a form (using Moodle's [[lib/formslib.php|Forms API]]) which allows users to upload or import files as attachments or media embedded into HTML.

Normally this works like this:
# User starts creation or re-edits an existing item in Moodle (eg forum post, resource, glossary entry etc)
# User presses some sort of button to browse for new files to attach or embed
# User sees our "Choose file..." dialog, which contains one or more repository instances.
# User chooses a file, the corresponding [[Repository plugins|Repository plugin]] takes care of copying the file into a "draft file area" within Moodle
# File appears in the text or as an attachment in the form.
# When the user hits save, the [[File API|File API]] is invoked to move the file from the draft file area into a permanent file area associated with that data

This document shows you exactly how to use Moodle forms to interact with users in a standard and secure way.

If you just want to write code to manipulate Moodle files internally (without user input) then see [[File API]].

==Form elements==

In Moodle 2.0 there are three file-related form elements for interacting with users:

# filemanager - the way to attach one or more files as a set
# editor - the way to specify a textarea with a HTML editor, and all the handling of images and movies within that HTML
# filepicker - a way to specify one file for the case when you want to process the file and throw it away

In Moodle 1.9 there were two other types which are now '''deprecated''' (they work, but please do not use these anymore)
# file - used to just allow a normal file upload from the desktop only.
# htmleditor - this old method of embedding a HTML editor in a textarea is not able to support repositories etc.

===filepicker===

File picker (''filepicker'') is a direct replacement of the older ''file'' formslib element.

It is intended for situations when you want the user to upload '''one''' file so you can process it and delete it, such as when you are importing data from a CSV file.

==== Using the filepicker element ====

<code php>
$mform->addElement('filepicker', 'userfile', get_string('file'), null,
array('maxbytes' => $maxbytes, 'accepted_types' => '*'));
</code>

==== Obtain the chosen file ====

The API for getting file contents is exactly the same as for ''file'' element.

<code php>
$content = $mform->get_file_content('userfile');
</code>

=== filemanager ===

The File Manager element improves on file picker by allowing you to manage more than one file. It is expected that the files will be stored permanently for future use (such as forum and glossary attachments).

==== Add file manager element ====

Example:
<code php>
$mform->addElement('filemanager', 'attachments', get_string('attachment', 'moodle'), null,
array('subdirs' => 0, 'maxbytes' => $maxbytes, 'maxfiles' => 50,
'accepted_types' => array('document') ));
</code>

Here are the fields for filemanager:

;'filemanager':This is a filemanager element :)
;elementname:The unique name of the element in the form
;elementlabel:The label string that users see
;attributes:(leave it as null)
;options: an array of further options for the filepicker (see below)

The options array can contain:

;subdirs:(Default 1) Are subdirectories allowed? (true or false)
;maxbytes:(Default 0) Restricts the total size of all the files.
;maxfiles:(Default -1) Restricts the total number of files.
;accepted_types:(Default *) You can specify what file types are accepted by filemanager. All current file types are listed in this file: [http://cvs.moodle.org/moodle/lib/filestorage/file_types.mm moodle/lib/filestorage/file_types.mm]. This is a [http://freemind.sourceforge.net/wiki/index.php/Main_Page freemind] file: if it is edited the changes will be immediately reflected in Moodle.

As of 2.3 file_types.mm is no longer used, instead the file types are listed in <code>get_mimetypes_array()</code> in filelib.php (https://github.com/moodle/moodle/blob/master/lib/filelib.php#L1360).

Example usage: '''array('audio', 'video', 'documents')''', you can include file extensions as well, for example: '''array('*.txt', '*.jpg', 'audio')'''.

==== Load existing files into draft area ====

<code php>
if (empty($entry->id)) {
$entry = new stdClass;
$entry->id = null;
}

$draftitemid = file_get_submitted_draft_itemid('attachments');

file_prepare_draft_area($draftitemid, $context->id, 'mod_glossary', 'attachment', $entry->id,
array('subdirs' => 0, 'maxbytes' => $maxbytes, 'maxfiles' => 50));

$entry->attachments = $draftitemid;

$mform->set_data($entry);

</code>

==== Store updated set of files ====

<code php>
if ($data = $mform->get_data()) {
// ... store or update $entry
file_save_draft_area_files($data->attachments, $context->id, 'mod_glossary', 'attachment',
$entry->id, array('subdirs' => 0, 'maxbytes' => $maxbytes, 'maxfiles' => 50));
}
</code>

===editor===
There are two ways of using the editor element in code, the first one is easier but expects some standardized fields. The second method is more low level.

====Simple use====
# name database fields: ''textfield'', ''textfieldformat'' (and ''textfieldtrust'' if required)
# create options array. note that context is the best, most local context you have available. <code php>$textfieldoptions = array('trusttext'=>true, 'subdirs'=>true, 'maxfiles'=>$maxfiles,
'maxbytes'=>$maxbytes, 'context'=>$context);</code>
# add editor ''textfield_editor'' to moodle form, pass options through custom data in form constructor, set $data->id to null if data not exist yet <code php>$mform->addElement('editor', 'textfield_editor', get_string('fieldname', 'somemodule'),
null, $textfieldoptions);</code>
# prepare data <code php>$data = file_prepare_standard_editor($data, 'textfield', $textfieldoptions, $context,
'mod_somemodule', 'somearea', $data->id);</code>
# get submitted data and after inserting/updating of data <code php>$data = file_postupdate_standard_editor($data, 'textfield', $textfieldoptions, $context,
'mod_somemodule', 'somearea', $data->id);</code>

Real world examples are in mod/glossary/edit.php and mod/glossary/comment.php

====Low level use====

When using editor element you need to preprocess and postprocess the data:
# detect if form was already submitted (usually means draft is area already exists) - ''file_get_submitted_draft_itemid()''
# prepare draft file area, temporary storage of all files attached to the text - ''file_prepare_draft_area()''
# convert encoded relative links to absolute links - ''file_prepare_draft_area()''
# create form and set current data
# after submission the changed files must be merged back into original area - ''file_save_draft_area_files()''
# absolute links have to be replaced by relative links - ''file_save_draft_area_files()''

=====Replace old htmleditor with editor=====

The file picker has been integrated with with TinyMCE to make the editor element. This new element should support all types on editors and should be able to switch them on-the-fly. Instances of the old htmleditor element in your forms should be replaced by the new editor element, this may need adding of new format and trusttext columns. For example:
<code php>
$mform->addElement('editor', 'entry', get_string('definition', 'glossary'), null,
array('maxfiles' => EDITOR_UNLIMITED_FILES));
</code>
The editor element can take following options: maxfiles, maxbytes, subdirs and changeformat. Please note that the embedded files is optional feature and is not expected be used everywhere.

'''Note''': the editor element now includes text format option. You should no longer use the separate format element type.

=====Prepare current data - text and files=====

<code php>
if (empty($entry->id)) {
$entry = new object();
$entry->id = null;
$entry->definition = '';
$entry->format = FORMAT_HTML;
}

$draftid_editor = file_get_submitted_draft_itemid('entry');
$currenttext = file_prepare_draft_area($draftid_editor, $context->id, 'mod_glossary', 'entry',
$entry->id, array('subdirs'=>true), $entry->definition);
$entry->entry = array('text'=>$currenttext, 'format'=>$entry->format, 'itemid'=>$draftid_editor);

$mform->set_data($entry);
</code>

If there are multiple files, they will share the same itemid.

=====Obtain text, format and save draft files=====

To retrieve editor content, you need to use following code:

<code php>
if ($fromform = $mform->get_data()) {
// content of editor
$messagetext = $fromform->entry['text'];
// format of content
$messageformat = $fromform->entry['format'];
}
</code>

When a user selects a file using the file picker, the file is initially stored in a draft file area, and a URL is inserted into the HTML in the editor that lets the person editing the content (but no one else) see the file.

When the user submits the form, we then need to save the draft files to the correct place in permanent storage. (Just like you have to call $DB->update_record('tablename', $data); to have the other parts of the form submission stored correctly.)

The save_files_from_draft_area function and replace absolute links with internal relative links do:
<code php>
$messagetext = file_save_draft_area_files($draftid_editor, $context->id, 'mod_glossary', 'entry',
$entry->id, array('subdirs'=>true), $messagetext);
</code>
; $context->id, 'component', 'proper_file_area' and $entry->id : correspond to the contextid, filearea and itemid columns in the [[File_API#Table:_files|files table]].
; $messagetext : this is the message text. As the files are saved to the real file area, the URLs in this content are rewritten.

All URLs in content that point to files managed to the File API are converted to a form that starts '@@PLUGINFILE@@/' before the content is stored in the database. That is what we mean by rewriting.

== File serving==

=== Convert internal relative links to absolute links ===

Before text content is displayed to the user, any URLs in the '@@PLUGINFILE@@/' form in the content need to be rewritten to the real URL where the user can access the files.
<code php>
$messagetext = file_rewrite_pluginfile_urls($messagetext, 'pluginfile.php',
$context->id, 'mod_mymodule', 'proper_file_area', $itemid);
</code>
; $messagetext : is the content containing the @@PLUGINFILE@@ URLs from the database.
; 'pluginfile.php' : there are a number of different scripts that can serve files with different permissions checks. You need to specify which one to use.
; $context->id, 'mod_mymodule', 'proper_file_area', $itemid : uniquely identifies the file area, as before.

=== Implement file serving access control ===

Attachments and embedded images should have the same access control like the text itself, in majority of cases these files are served using pluginfile.php. Access control is defined in ''module/lib.php'' file in function ''module_pluginfile()''.

== File browsing support ==
Only owner of each file area is allowed to use low level File API function to access files, other parts of Moodle should use file browsing API.

Activities may specify browsing support in own module/lib.php file by implementing functions module_get_file_areas() and module_get_file_info().

== Upgrading your code ==
Here I will attempt to describe some simple steps you can take to upgrade your file-handling form elements from pre-2.0 code to 2.0. We will use the example of glossary, since it has been used above.

=== Preparing your options ===
Unless you are happy with the defaults, you will need to define an array of options for each file-handling form element. You could define it at different places, but it's best to put it in one place and make the array(s) available to other files if they need it. In the majority of cases, this will be in a file like edit.php

Previous code in mod/glossary/edit.php:
<code php>
$mform =& new mod_glossary_entry_form(null, compact('cm', 'glossary', 'hook', 'mode', 'e', 'context'));
</code>
New code:
<code php>
$maxbytes = $course->maxbytes;
// Could also use $CFG->maxbytes if you are not coding within a course context

$definitionoptions = array('subdirs'=>false, 'maxfiles'=>99, 'maxbytes'=>$maxbytes, 'trusttext'=>true,
'context'=>$context);
$attachmentoptions = array('subdirs'=>false, 'maxfiles'=>99, 'maxbytes'=>$maxbytes);
$mform = new mod_glossary_entry_form(null, array('current'=>$entry, 'cm'=>$cm, 'glossary'=>$glossary,
'definitionoptions'=>$definitionoptions,
'attachmentoptions'=>$attachmentoptions));
</code>
Note that the data being passed to the form constructor have changed also, but this is not part of the file API changes, I just include them to avoid confusion.

These options are for the htmleditor (definition field) and the filemanager (attachment field). They are used by a file called edit_form.php.

=== Element preparation ===
Before we look at this, however, we need to "prepare" the elements so that they can correctly display existing embedded images and attached files when you are editing a record instead of just creating one. So, let's take the code we've got so far in edit.php and add to it:

Currently upgraded code in edit.php:
<code php>
$mform = new mod_glossary_entry_form(null, array(
'current'=>$entry,
'cm'=>$cm,
'glossary'=>$glossary,
'definitionoptions'=>$definitionoptions,
'attachmentoptions'=>$attachmentoptions));
</code>
New code with element preparation:
<code php>
$entry = file_prepare_standard_editor($entry, 'definition', $definitionoptions, $context,
'mod_glossary', 'entry', $entry->id);
$entry = file_prepare_standard_filemanager($entry, 'attachment', $attachmentoptions, $context,
'mod_glossary', 'attachment', $entry->id);
$mform = new mod_glossary_entry_form(null, array('current'=>$entry, 'cm'=>$cm, 'glossary'=>$glossary,
'definitionoptions'=>$definitionoptions,
'attachmentoptions'=>$attachmentoptions));
</code>
Things to note:
* $entry in this case is simply a stdClass object which may either represent a new glossary entry or an existing one.
* $entry->id must be the unique identifier for the current object. If we are creating a new entry, it will be null, but in all cases it must be defined.
* These two functions (file_prepare_standard_editor and file_prepare_standard_filemanager) are shortcuts functions that take care of some of the tedious setting up for you, but they make a couple of assumptions:
*# You '''must''' name the form element as {element}_editor or {element}_filemanager (see next section)
*# You '''must''' have at least the following fields in the database: {element} and {element}summary, as described earlier in this documentation

We can now look at the upgrades needed in the form definition file.

=== Form definition ===
Previous code in mod/glossary/edit_form.php:
<code php>
$mform->addElement('htmleditor', 'definition', get_string('definition', 'glossary'),
array('rows'=>20));
$mform->setType('definition', PARAM_RAW);
$mform->addRule('definition', null, 'required', null, 'client');
$mform->setHelpButton('definition', array('writing', 'richtext'), false, 'editorhelpbutton');
$mform->addElement('format');
// a bit further...
$this->set_upload_manager(new upload_manager('attachment', true, false, $COURSE, false, 0,
true, true, false));
$mform->addElement('file', 'attachment', get_string('attachment', 'forum'));
$mform->setHelpButton('attachment', array('attachment', get_string('attachment', 'glossary'),
'glossary'));
</code>
New code:
<code php>
$definitionoptions = $this->_customdata['definitionoptions'];
$attachmentoptions = $this->_customdata['attachmentoptions'];
// a bit further...
$mform->addElement('editor', 'definition_editor', get_string('definition', 'glossary'), null,
$definitionoptions);
$mform->setType('definition_editor', PARAM_RAW);
$mform->addRule('definition_editor', get_string('required'), 'required', null, 'client');
// a bit further...
$mform->addElement('filemanager', 'attachment_filemanager', get_string('attachment', 'glossary'),
null, $attachmentoptions);
$mform->setHelpButton('attachment_filemanager', array('attachment2',
get_string('attachment', 'glossary'), 'glossary'));
</code>

Note the following:
* The format element and the help button are no longer required for the HTML editor element
* The name of the form element needs to be changed by adding '_editor' or '_manager' to the original name. This is a naming convention that is used by a couple of functions we will look at shortly
* Make sure $definitionoptions has context parameter, else system context is used and editor will not respect filter settings.

=== Handling submitted data ===
The final step is to handle the submitted data properly, i.e. retrieve the files and save them to disk, associating them with the record we have just created (a glossary entry in our example). This happens in edit.php:

Previous code in edit.php:
<code php>
// Section that updates an entry:
$todb->id = $e;
$dir = glossary_file_area_name($todb);
if ($mform->save_files($dir) and $newfilename = $mform->get_new_filename()) {
$todb->attachment = $newfilename;
}

// Section that adds an entry:
if ($todb->id = insert_record("glossary_entries", $todb)) {
$e = $todb->id;
$dir = glossary_file_area_name($todb);
if ($mform->save_files($dir) and $newfilename = $mform->get_new_filename()) {
set_field("glossary_entries", "attachment", $newfilename, "id", $todb->id);
}
}
</code>
New code:
<code php>
// $todb was renamed to $entry, and the code was refactored
// so that the file-handling code is only used once for either an add or an update action.
// If an entry is being added, $DB->insert() has already been called, so we have a valid $entry->id
$entry = file_postupdate_standard_editor($entry, 'definition', $definitionoptions, $context,
'mod_glossary', 'entry', $entry->id);
$entry = file_postupdate_standard_filemanager($entry, 'attachment', $attachmentoptions, $context,
'mod_glossary', 'attachment', $entry->id);
// store the updated value values
$DB->update_record('glossary_entries', $entry);
</code>
Things to note:
* If you are adding a new record, you will still need to call update_record after calling the file_postupdate* functions

=== Gotchas ===
A few things to keep in mind:
* Make sure that you instantiate the moodle form before any call to $OUTPUT->header()

== See also ==

* [[File API]]
* [[Using the file API]]
* [[Repository plugins]]
* [[Portfolio API]]
* MDL-14589 - File API Meta issue
* [http://moodle.org/mod/forum/discuss.php?d=207748 Adding a text editor to a Moodle form]

[[Category:Files]]
[[Category:Repositories]]

lib/formslib.php Form Definition

2012-07-24T18:35:41Z

Ravenink:

{{Formslib}}
== ''definition()'' ==

The definition of the elements to be included in the form, their 'types' (PARAM_*), helpbuttons included, etc. is all included in a function you must define in your class.

''definition()'' is used to define the elements in the form and '''this definition will be used for validating data submitted as well as for printing the form.''' For select and checkbox type elements only data that could have been selected will be allowed. And only data that corresponds to a form element in the definition will be accepted as submitted data.

The ''definition()'' should include all elements that are going to be used on form, some elements may be removed or tweaked later in ''definition_after_data()''. Please do not create conditional elements in ''definition()'', the definition() should not directly depend on the submitted data.

Note that the definition function is called when the form class is instantiated. There is no option to (say) manipulate data in the class (that may affect the rendering of the form) between instantiating the form and calling any other methods.

<code php>
require_once("$CFG->libdir/formslib.php");

class simplehtml_form extends moodleform {

function definition() {
global $CFG;

$mform =& $this->_form; // Don't forget the underscore!

$mform->addElement()... // Add elements to your form
...
} // Close the function
} // Close the class
</code>
===Passing parameters to the Form===

The constructor for ''moodleform'' allows a number of parameters including one (''$customdata'') to permit an array of arbitrary data to be passed to your form.

For example, you can pass the data "$email" and "$username" to the Form's class for use inside (say) the definition.
<code php>
...
$mform_simple = new simplehtml_form( null, array('email'=>$email, 'username'=>$username ) );
...
</code>
(the first parameter is $action, ''null'' will case the form action to be determined automatically)

Secondly, inside the form definition you can use those parameters to set the default values to some of the form's fields
<code php>
...
$mform->addElement('text', 'email', get_string('email'), 'maxlength="100" size="25" ');
$mform->setType('email', PARAM_NOTAGS);
$mform->addRule('email', get_string('missingemail'), 'required', null, 'server');
// Set default value by using a passed parameter
$mform->setDefault('email',$this->_customdata['email']);
...
</code>

==Use Fieldsets to group Form Elements==

You use code like this to open a fieldset with a ''legend''. <br />
('''Note''': Some themes turn off legends on admin setting pages by using CSS: <nowiki>#adminsettings legend {display:none;}</nowiki>.)

<code php>
$mform->addElement('header', 'nameforyourheaderelement', get_string('titleforlegened', 'modulename'));
</code>

You can't yet nest these visible fieldsets unfortunately. But in fact groups of elements are wrapped in invisible fieldsets.

You close a fieldset with moodle_form's closeHeaderBefore method. You tell closeHeaderBefore the element before you wish to end the fieldset. A fieldset is automatically closed if you open a new one. You need to use this code only if you want to close a fieldset and the subsequent form elements are not to be enclosed by a visible fieldset (they are still enclosed with an invisibe one with no legend) :

<code php>
$mform->closeHeaderBefore('buttonar');
</code>

==addElement==

Use the addElement method to add an element to a form. The first few arguments are always the same. The first param is the type of the element to add. The second is the elementname to use which is normally the html name of the element in the form. The third is often the text for the label for the element.

Some examples are below :
=== button ===

<code php>
$mform->addElement('button', 'intro', get_string("buttonlabel"));
</code>

A button element. If you want a submit or cancel button see 'submit' element.

=== checkbox ===

<code php>
$mform->addElement('checkbox', 'ratingtime', get_string('ratingtime', 'forum'));
</code>

This is a simple checkbox. The third parameter for this element is the label to display on the left side of the form. You can also supply a string as a fourth parameter to specify a label that will appear on the right of the element. Checkboxes and radio buttons can be grouped and have individual labels on their right.

You can have a 5th parameter $attributes, as on other elements.

'''BEWARE:''' Unchecked checkboxes return nothing at all (as if they didn't exist). This can surprise the unwary. You may wish to use advcheckbox instead, which does return a value when not checked. 'Advcheckbox' eliminates this problem.

==== advcheckbox ====
<code php>
$mform->addElement('advcheckbox', 'ratingtime', get_string('ratingtime', 'forum'), 'Label displayed after checkbox', array('group' => 1), array(0, 1));
</code>

Similar to the checkbox above, but with some important improvements:

# The (optional) 5th parameter is a normal $attributes array, normally used to set HTML attributes for the <input> element. However, a special value of 'group' can be given, which will add a class name to the element, and enable its grouping for a [[lib/formslib.php_add_checkbox_controller|checkbox controller]]
#The (optional) 6th parameter is an array of values that will be associated with the checked/unchecked state of the checkbox. With a normal checkbox you cannot choose that value, and in fact an unchecked checkbox will not even be sent with the form data.
#It returns a 0 value when unchecked. Compare with the ordinary checkbox which does not return anything at all.

=== choosecoursefile ===
{{Moodle 1.9}}
<code php>
$mform->addElement('choosecoursefile', 'mediafile', get_string('mediafile', 'lesson'), array('courseid'=>$COURSE->id));
</code>

Choose a file from the course files area. The fourth option is a list of options for the element.

'''Note: This has been superceded by [[#filepicker|filepicker]] in Moodle 2.'''

<code php>
array('courseid' =>null, //if it is null (default then use global $COURSE
'height' =>500, // height of the popup window
'width' =>750, // width of the popup window
'options' =>'none'); //options string for the pop up window
//eg. 'menubar=0,location=0,scrollbars,resizable'
</code>

You can also pass an optional 5th parameter of attributes, as for other elements. The most useful way of using that is something like
<code php>array('maxlength' => 255, 'size' => 48)</code>
to control the maxlength / size of the text box (note size will default to 48 if not specified)

Finally, as this element is a group containing two elements (button + value), you can add validation rules by using the '''addGroupRule()''' method in this (complex) way:

<code php>$mform->addGroupRule('elementname', array('value' => array(array(list, of, rule, params, but, fieldname))));</code>

Where: '''"elementname"''' is the name of the choosecoursefile group element, '''"value"''' is the name of the text field within the group and the '''"list, of, addrule, params, but, fieldname"''' is exactly that, the list of fields in the normal addRule() function but ommiting the first one, the fieldname.

For example, the [http://cvs.moodle.org/moodle/mod/resource/type/file/resource.class.php?view=markup file/url resource type], uses one "choosecoursefile" element, and it controls the maximum length of the field (255) with this use of addGroupRule():

<code php>$mform->addGroupRule('reference', array('value' => array(array(get_string('maximumchars', '', 255), 'maxlength', 255, 'client'))));</code>

=== date_selector ===

<code php>
$mform->addElement('date_selector', 'assesstimefinish', get_string('to'));
</code>

This is a date selector. You can select a Day, Month and Year using a group of select boxes. The fourth param here is an array of options. The defaults for the options are :

<code php>
array(
'startyear' => 1970,
'stopyear' => 2020,
'timezone' => 99,
'optional' => false
);
</code>

You can override these defaults by supplying an array as fourth param with one or more keys with a value to override the default. You can supply a fifth param of attributes here as well.

=== date_time_selector ===

<code php>
$mform->addElement('date_time_selector', 'assesstimestart', get_string('from'));
</code>

This is a group of select boxes to select a date (Day Month and Year) and time (Hour and Minute). When submitted, submitted data is processed and a timestamp is passed to $form->get_data(); the fourth param here is an array of options. The defaults for the options are:

<code php>
array(
'startyear' => 1970,
'stopyear' => 2020,
'timezone' => 99,
'step' => 5
);
</code>

You can override these defaults by supplying an array as fourth param with one or more keys with a value to override the default. You can supply a fifth param of attributes here as well.

===duration===
{{Moodle 2.0}}

<code php>
$mform->addElement('duration', 'timelimit', get_string('timelimit', 'quiz'));
</code>
This field type lets the user input an interval of time. It comprises a text field, where you can type a number, and a dropdown for selecting a unit (days, hours, minutes or seconds). When submitted the value is converted to a number of seconds.

You can add a fourth parameter to give options. At the moment the only option supported is here is an array of options. The defaults for the options is:
<code php>array('optional' => true)</code>

You can also pass an optional 5th parameter of attributes, as for other elements. The most useful way of using that is something like
<code php>array('size' => 5)</code>
to control the size of the text box.

=== editor ===

This replaces the old htmleditor field type. It allows the user to enter rich text content in a variety of formats.

<code php>
$mform->addElement('editor', 'fieldname', get_string('labeltext', 'langfile'));
$mform->setType('fieldname', PARAM_RAW);
</code>

If you would like to let the user use the filepicker to upload images etc. that are used in the content, then see [[Using_the_File_API_in_Moodle_forms]].

You can supply a fourth param to htmleditor of an array of options that are mostly related to file handling:

<code php>
array(
'subdirs'=>0,
'maxbytes'=>0,
'maxfiles'=>0,
'changeformat'=>0,
'context'=>null,
'noclean'=>0,
'trusttext'=>0);
</code>

=== file ===

File upload input box with browse button. In the form definition type

<code php>
$mform->addElement('file', 'attachment', get_string('attachment', 'forum'));
</code>

after form submission and validation use

<code php>
if ($data = $mform->get_data()) {
...
$mform->save_files($destination_directory);
...
}
</code>

If there is no requirement to save the file, you can read the file contents directly into a string as follows...

<code php>
$mform->get_file_content('attachment');
</code>

If you need advanced settings such as required file, different max upload size or name of uploaded file

<code php>
$this->set_upload_manager(new upload_manager('attachment', true, false, $COURSE, false, 0, true, true, false));
$mform->addElement('file', 'attachment', get_string('attachment', 'forum'));
$mform->addRule('attachment', null, 'required');

</code>

<code php>
if ($data = $mform->get_data()) {
...
$mform->save_files($destination_directory);
$newfilename = $mform->get_new_filename();
...
}
</code>

When porting old code it is also possible to use the upload manager directly for processing of uploaded files.

Please note that if using set_upload_manager() it must be before addElement('file',..).

{{Moodle 2.0}}
File uploading was rewritten in 2.0. Please see inline docs for now. This page will be updated when the new API stabilises.

===filepicker===
{{Moodle 2.0}}
General replacement of ''file'' element.

<code php>
$mform->addElement('filepicker', 'userfile', get_string('file'), null, array('maxbytes' => $maxbytes, 'accepted_types' => '*'));
</code>
See also [[Using the File API in Moodle forms]]

=== hidden ===
<code php>
$mform->addElement('hidden', 'reply', 'yes');
</code>

A hidden element. Set the element name (in this case '''reply''') to the stated value (in this case '''yes''').

=== html ===
You can add arbitrary HTML to your Moodle form:

<code php>
$mform->addElement('html', '<div class="qheader">');
</code>

See [http://moodle.org/mod/forum/discuss.php?d=126935 "Question: Can I put a moodleform inside a table td?"] for a concrete example.

=== htmleditor & format ===

These elements are now deprecated. Please use the [[#editor|editor]] field type instead.

===modgrade===
<pre>
$mform->addElement('modgrade', 'scale', get_string('grade'), false);
</pre>
This is a custom element for selecting a grade for any activity module. The fourth argument is whether to include an option for no grade which has a value 0. This select box does include scales. The default is true, include no grade option.

A helpbutton is automatically added.

===modvisible===
<pre>
$mform->addElement('modvisible', 'visible', get_string('visible'));
</pre>
This is a custom element for selecting a grade visibility in an activity mod update form.

===password===
<pre>
$mform->addElement('password', 'password', get_string('label'), $attributes);
</pre>

A password element. Fourth param is an array or string of attributes.

===passwordunmask===
{{Moodle 1.9}}
<pre>
$mform->addElement('passwordunmask', 'password', get_string('label'), $attributes);
</pre>

A password element with option to show the password in plaintext. Fourth param is an array or string of attributes.

=== radio ===
{{Moodle 2.3}}
<code php>
$radioarray=array();
$radioarray[] =& $mform->createElement('radio', 'yesno', '', get_string('yes'), 1, $attributes);
$radioarray[] =& $mform->createElement('radio', 'yesno', '', get_string('no'), 0, $attributes);
$mform->addGroup($radioarray, 'radioar', '', array(' '), false);
</code>

Second param names the radio button and should be the same for each button in the group in order to toggle correctly. Third param would be the label for the form element but is generally ignored as this element will always be in a group which has it's own label. Fourth param is a string, a label to be displayed on the right of the element. The fifth is the value for this radio button. $attributes can be a string or an array of attributes.

It is possible to add help to individual radio buttons but this requires a custom template to be defined for the group elements. See MDL-15571.

Since 2.3 it cannot be statically called anymore, so we need to call createElement from $mform reference.

==== setDefault ====

To set the default for a radio button group as above use the following :

<code php>
$mform->setDefault('yesno', 0);
</code>

This would make the default 'no'.

===select===
<pre>
$mform->addElement('select', 'type', get_string('forumtype', 'forum'), $FORUM_TYPES, $attributes);
</pre>

The fourth param for this element is an array of options for the select box. The keys are the values for the option and the value of the array is the text for the option. The fifth param $attributes is optional, see text element for description of attributes param.

It is also possible to create a select with certain options disabled, using [http://stackoverflow.com/questions/2138089/how-can-i-use-quickform-to-add-disabled-select-options/2150275#2150275 this technique].

====multi-select====
<pre>
$select = &$mform->addElement('select', 'colors', get_string('colors'), array('red', 'blue', 'green'), $attributes);
$select->setMultiple(true);
</pre>

=====setSelected=====

To set the default selected item in a select element, you should use the 'setSelected' function, as follows:
<code>
$select = &$mform->addElement('select', 'colors', get_string('colors'), array('red', 'blue', 'green'), $attributes);
$select->setSelected('blue');
</code>
However you probably don't want to do this. Instead you probably want to use setDefault, or set it using the form's setData method.

===selectyesno===
<pre>
$mform->addElement('selectyesno', 'maxbytes', get_string('maxattachmentsize', 'forum'));
</pre>

If you want a yes / no select box this one automatically translates itself and has value 1 for yes and 0 for no.

===selectwithlink===
<pre>
$options = array();
$mform->addElement('selectwithlink', 'scaleid', get_string('scale'), $options, null,
array('link' => $CFG->wwwroot.'/grade/edit/scale/edit.php?courseid='.$COURSE->id, 'label' => get_string('scalescustomcreate')));
</pre>
select type element with options containing link
===static===
<pre>
$mform->addElement('static', 'description', get_string('description', 'exercise'),
get_string('descriptionofexercise', 'exercise', $COURSE->students));
</pre>

This is a static element. It should be used with care if it is used to display a static piece of text with a label. The third param is the label and the fourth is the static text itself.

===submit, reset and cancel===

<pre>
//normally you use add_action_buttons instead of this code
$buttonarray=array();
$buttonarray[] = &$mform->createElement('submit', 'submitbutton', get_string('savechanges'));
$buttonarray[] = &$mform->createElement('reset', 'resetbutton', get_string('revert'));
$buttonarray[] = &$mform->createElement('cancel');
$mform->addGroup($buttonarray, 'buttonar', '', array(' '), false);
$mform->closeHeaderBefore('buttonar');
</pre>

A 'Submit' type element is a submit type form element which will submit the form. A 'Reset' will not submit the form but will reset any changes the user has made to form contents. A 'Cancel' element cancels form submission. You need to have a branch in your code before you check for get_data() to check if submission has been cancelled with is_cancelled(); See the example on the usage page.

You should name your submit and reset buttons 'submitbutton' and 'resetbutton' or something similar (not 'submit' and 'reset'). This avoids problems in JavaScript of collisions between form element names and names of JavaScript methods of the form object.

====add_action_buttons($cancel = true, $submitlabel=null);====

You will normally use this helper function which is a method of moodleform to add all the 'action' buttons to the end of your form. A boolean parameter allow you to specify whether to include a cancel button and specify the label for your submit button (pass the result of get_string). Default for the submit button label is get_string('savechanges'). Note the '''$this''' not '''$mform'''

<pre>
$this->add_action_buttons();
</pre>

===text===

<pre>
$mform->addElement('text', 'name', get_string('forumname', 'forum'), $attributes);
</pre>
For a simple text element. Your fourth parameter here can be a string or array of attributes for the text element. The following are equivalent :
<pre>
$attributes='size="20"';
$attributes=array('size'=>'20');
</pre>

Generally you are encouraged to use CSS instead of using attributes for styling.

A format element can be used as a format select box. It will be non-selectable if you're using an html editor.

The third param for this element is $useHtmlEditor and it defaults to null in which case an html editor is used if the browser and user profile support it.

===textarea===

<pre>
$mform->addElement('textarea', 'introduction', get_string("introtext", "survey"), 'wrap="virtual" rows="20" cols="50"');
</pre>

A textarea element. If you want an htmleditor use htmleditor element. Fourth element here is a string or array of attributes.

===recaptcha===
{{Moodle 1.9}}
<pre>
$mform->addElement('recaptcha', 'recaptcha_field_name', $attributes);
</pre>

Use this recaptcha element to reduce the spam risk in your forms. Third element here is a string or array of attributes. Take care to get an API key from http://recaptcha.net/api/getkey before using this element.

To check whether recaptcha is enabled at site level use:
<pre>
if (!empty($CFG->recaptchapublickey) && !empty($CFG->recaptchaprivatekey)) {
//recaptcha is enabled
}
</pre>

===tags===
{{Moodle 2.0}}

<pre>
$mform->addElement('tags', 'field_name', $lable, $options, $attributes);
</pre>

Used for editing a list of tags, for example on a blog post.

There is only one option available, 'display', which should be set to one of the contstants MoodleQuickForm_tags::ONLYOFFICIAL, NOOFFICIAL or DEFAULTUI. This controls whether the official tags are listed for easy selection, or a text area where arbitrary tags may be typed, or both. The default is both.

The value should be set/returned as an array of tags.

===grading===
<code php>
$mform->addElement('grading', 'advancedgrading', get_string('grade').':', array('gradinginstance' => $gradinginstance));
</code>

Custom element for advanced grading plugins.

When adding the 'grading' element to the form, developer must pass an object of class gradingform_instance as $attributes['gradinginstance']. Otherwise an exception will be thrown.

===questioncategory===
<code php>
$mform->addElement('questioncategory', 'category', get_string('category', 'question'),
array('contexts'=>$contexts, 'top'=>true, 'currentcat'=>$currentcat, 'nochildrenof'=>$currentcat));
</code>
Creates a drop down element to select a question category.

Options are:
'''contexts''' - (required) context in which question appears
'''currentcat''' - (optional) course category
'''top''' - (optional) if true will put top categories on top
'''nochildrenof''' - (optional) Format categories into an indented list reflecting the tree structure

==addGroup==

A 'group' in formslib is just a group of elements that will have a label and will be included on one line.

For example typical code to include a submit and cancel button on the same line :

<pre>
$buttonarray=array();
$buttonarray[] =& $mform->createElement('submit', 'submitbutton', get_string('savechanges'));
$buttonarray[] =& $mform->createElement('submit', 'cancel', get_string('cancel'));
$mform->addGroup($buttonarray, 'buttonar', '', array(' '), false);
</pre>

You use the same arguments for createElement as you do for addElement. Any label for the element in the third argument is normally ignored (but not in the case of the submit buttons above where the third argument is not for a label but is the text for the button).

Here's a bad example (don't do this for real, use the 'optional' => true option of the date element): putting a date_selector (which is itself a group of elements) and a checkbox on the same line, note that you can disable every element in the group using the group name 'availablefromgroup' but it doesn't disable the controlling element the 'availablefromenabled' checkbox:

<pre>
$availablefromgroup=array();
$availablefromgroup[] =& $mform->createElement('date_selector', 'availablefrom', '');
$availablefromgroup[] =& $mform->createElement('checkbox', 'availablefromenabled', '', get_string('enable'));
$mform->addGroup($availablefromgroup, 'availablefromgroup', get_string('availablefromdate', 'data'), ' ', false);
$mform->disabledIf('availablefromgroup', 'availablefromenabled');
</pre>

==addRule==
<pre>
$mform->addRule('elementname', get_string('error'), 'rule type', 'extraruledata', 'server'(default), false, false);
</pre>

The first param(element) is an element name and second(message) is the error message that will be displayed to the user.
The third parameter(type) is the type of rule. The fourth param(format) is used for extra data needed with some rules such as minlength and regex. The fifth parameter(validation) validates input data on server or client side, if validation is done on client side then it will be checked on the server side as well.

<pre>
* @param string $element Form element name
* @param string $message Message to display for invalid data
* @param string $type Rule type, use getRegisteredRules() to get types
* @param string $format (optional)Required for extra rule data
* @param string $validation (optional)Where to perform validation: "server", "client"
* @param boolean $reset Client-side validation: reset the form element to its original value if there is an error?
* @param boolean $force Force the rule to be applied, even if the target form element does not exist
</pre>

'''Common Rule Types'''
* required
* maxlength
* minlength
* rangelength
* email
* regex
* lettersonly
* alphanumeric
* numeric
* nopunctuation
* nonzero
* callback
* compare

===Server side and Client side===
In case you use the ''Client side'' validation option, you can mainly check for an empty or not input field. unless you write some ''Client side'' code which will probably be JavaScript functions to verify the data inside the input fields before it is submitted to the server. It could save some time if those functions are short, simple and quick to compute.
In case you need a more complex validation checks which relay on Moodle's internal PHP libraries (or other/external PHP libraries) you better use the ''Server side'' validation checks. Where you can query the DB, write complex PHP validation functions and much much more, that are not available (easily) when using JavaScript on the client's side.

==setHelpButton==
{{Moodle 1.9}}

<pre>
$mform->setHelpButton('lessondefault', array('lessondefault', get_string('lessondefault', 'lesson'), 'lesson'));
</pre>
First param is an elementname and the second param is an array of params that are passed to helpbutton in weblib.php. Params are :

<pre>
* @param string $page The keyword that defines a help page
* @param string $title The title of links, rollover tips, alt tags etc
* 'Help with' (or the language equivalent) will be prefixed and '...' will be stripped.
* @param string $module Which module is the page defined in
* @param mixed $image Use a help image for the link? (true/false/"both")
* @param boolean $linktext If true, display the title next to the help icon.
* @param string $text If defined then this text is used in the page, and
* the $page variable is ignored.
* @param boolean $return If true then the output is returned as a string, if false it is printed to the current page.
* @param string $imagetext The full text for the helpbutton icon. If empty use default help.gif
</pre>
Make sure you don't set boolean $return to false.

You need to do use this method after addElement();

==addHelpButton==
{{Moodle 2.0}}

<code php>
$mform->addHelpButton('api_key_field', 'api_key', 'block_extsearch');
</code>

In Moodle 2.0 the "setHelpButton" method has been deprecated in favor of the "addHelpButton" method, which has a simplified interface and uses $OUTPUT->help_icon() on the back end. The following parameters are expected:

<code php>
/**
* @param $elementname The name of the form element to add the help button for
* @param $identifier The identifier for the help string and its title (see below)
* @param $component The component name to look for the help string in
*/
</code>
Unlike in Moodle 1.9, it is no longer necessary to put your help pages in separate HTML files. Instead, the function looks for two strings:

# get_string($identifier, $component) // The title of the help page
# get_string("{$identifier}_help", $component) // The content of the help page

So you will need to have '''$identifier''' and '''{$identifier}_help''' defined in order for the help button to be created properly. For example the multiple choice question editing form has a button for shuffling the answers.
<code php>
$mform->addHelpButton('shuffleanswers', 'shuffleanswers', 'qtype_multichoice');
</code>
and so the language file includes the strings
<code php>
$string['shuffleanswers'] = 'Shuffle the choices?';
$string['shuffleanswers_help'] = 'If enabled,.....';
</code>
You can also add the language string like
<code php>
$string['shuffleanswers_link'] = 'question/shuffleanswers';
</code>
to add a link to more help on Moodle docs. See [[String_API]] for more information about help icons.

==setDefault==

<pre>
$mform->addElement('select', 'grade', get_string('gradeforsubmission', 'exercise'), $grades);
$mform->setHelpButton('grade', array('grade', get_string('gradeforsubmission', 'exercise'), 'exercise'));
$mform->setDefault('grade', 100);
</pre>

Set the default of the form value with setDefault($elementname, $value); where elementname is the elementname whose default you want to set and $value is the default to set. We set the defaults for the form in definition(). This default is what is used if no data is loaded into the form with set_data(); eg. on display of the form for an 'add' rather than 'update' function.

==disabledIf==

For any element or groups of element in a form you can conditionally disable the group or individual element depending on conditions.

You can use $mform->disabledIf($elementName, $dependentOn, $condition = 'notchecked', $value='1')

* elementname can be a group. If you specify a group all elements in the group will be disabled (if dependentOn is in elementname group that is ignored and not disabled). These are the element names you've used as the second argument in addElement or addGroup.
* dependentOn is the actual name of the element as it will appear in html. This can be different to the name used in addGroup particularly but also addElement where you're adding a complex element like a date_selector. Check the html of your page. You typically make the depedentOn a checkbox or select box.
* $condition will be 'notchecked', 'checked', 'noitemselected', 'eq' or, if it is anything else, we test for 'neq'.
** If $condition is 'eq' or 'neq' then we check the value of the dependentOn field and check for equality (==) or nonequality (!=) in js
** If $condition is 'checked' or 'notchecked' then we check to see if a checkbox is checked or not.
** If $condition is 'noitemselected' then we check to see whether nothing is selected in a dropdown list.

Examples:
// Disable my control unless a checkbox is checked.
$mform->disabledIf('mycontrol', 'somecheckbox');

// Disable my control if a checkbox '''is''' checked.
$mform->disabledIf('mycontrol', 'somecheckbox', 'checked');

// Disable my control when a dropdown has value 42.
$mform->disabledIf('mycontrol', 'someselect', 'eq', 42);

The possible choices here are in the dependency manager in lib/form/form.js.

==setType==

PARAM_* types are used to specify how a submitted variable should be cleaned. These should be used for get parameters such as id, course etc. which are used to load a page and also with setType(); method. Every form element should have a type specified except select, radio box and checkbox elements, these elements do a good job of cleaning themselves (only specified options are allowed as user input).

===Most Commonly Used PARAM_* Types===

These are the most commonly used PARAM_* types and their proper uses. More types can be seen in moodlelib.php starting around line 100.

* PARAM_CLEAN is deprecated and you should try to use a more specific type.
* PARAM_TEXT should be used for cleaning data that is expected to be plain text. It will strip all html tags. But will still let tags for multilang support through.
* PARAM_NOTAGS should be used for cleaning data that is expected to be plain text. It will strip *all* html type tags. It will still *not* let tags for multilang support through. This should be used for instance for email addresses where no multilang support is appropriate.
* PARAM_RAW means no cleaning whatsoever, it is used mostly for data from the html editor. Data from the editor is later cleaned before display using format_text() function. PARAM_RAW can also be used for data that is validated by some other way or printed by p() or s().
* PARAM_INT should be used for integers.
* PARAM_ACTION is an alias of PARAM_ALPHA and is used for hidden fields specifying form actions.

==References==

* [http://www.midnighthax.com/quickform.php PEAR HTML QuickForm Getting Started Guide] by Keith Edmunds of Midnighthax.com
* [http://pear.php.net/manual/en/package.html.html-quickform.php PEAR::HTML_QuickForm manual]

[[Category:Formslib]]
[[Category:Interfaces]]

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