Render library specification
| Renderer consistency | |
|---|---|
| Project state | Specification |
| Tracker issue | https://tracker.moodle.org/browse/MDL-45770 |
| Discussion | https://moodle.org/mod/forum/discuss.php?d=261202 |
| Assignee | Damyon, Sam |
Note: This page is a work-in-progress. Feedback and suggested improvements are welcome. Please join the discussion on moodle.org or use the page comments.
Project Goals
- Add an element library to Moodle (A page in Moodle listing all of the renderables and how they look in the current theme)
- Add a complete set of core renderables that should be capable of completely rendering every new user interface
- Update the Output API documentation
- Create a output guide documentation including best practices.
Benefits
- Make it easier to create user interfaces.
- Make it easier to style the user interface.
- Make it easier for themers to customise the user interface.
- Better facilitate frontend frameworks in Themes.
- Better facilitate usable and accessible design.
- Give Moodle a more consistent look and feel.
- Improve site performance by reducing the CSS footprint.
Understanding renderers in Moodle
Renderers have been around since Moodle 2.0 and are now the requirement when writing any code that produces output. Renderers come in many shapes and forms depending upon the developers take on how output should be produced.
When renderables were introduced - the API was designed to make it easy for existing code to be updated to make use of renderers and renderables. A renderable is an interface with no methods, so any existing class could be made to implement renderable. This means that the renderable class can be a mixture of data and methods that perform logic associated with the module. This also means that the renderer can call those methods on the renderable class - effectively using the API of the module. The problem with this - is that it complicates the renderer and makes it harder to override in a theme - the themer requires knowledge about the API for the module. Some renderables in core are built as separate classes - only used for the purpose of supplying data to the renderer - here there is a clear separation of the logic - and the properties of the renderable are made up of only simple types that can be checked for in the renderer - e.g. access checks are done in advance and the result is put into a boolean in the renderable. The current renderers / renderables in Moodle are a mixture of these styles.
Because there is no mandated organisation, nor has there ever been, there is immense variation in what constitutes content to a renderer.
One of the upsides to our current render system is that you are not limited to having a single renderer for a component, you can make use of language capabilities and the output framework and create layers of renderers to cut back code duplication and to aid in preparing a base for consistent structuring and output.
Into the equation we add targets and subtypes. Targets allow us to create both standard renderers and renderers specific to the needs of the output method. Standard being HTML, without output methods including CLI, AJAX, HTML email and plain text email.
People have never being constrained as to how they implement a renderer. We've being happy enough to simply guide them towards using renderers because of the benefits they provide and while there are numerous benefits there are two fundamental benefits:
- A change in thinking
- It requires developers to think about their code organisation. Renderers were introduced in a time before Object Orientation was used in Moodle, and logic and output were tightly intermingled in most code. Renderers were about separating logic and design and while what was created was not always perfect it was always an improvement.
- An extensible approach to output
- The render system allows for the overriding of renderers to occur. Theme designers can overwrite any renderer in their theme. The more that renderers that get implement the more of Moodle you can customise.
Understanding themes
Themes are without a doubt the most widely customised plugin provided by Moodle. But we are currently struggling with several problems with renderers and themes as they are being implemented currently.
1. There is no strict relationship between the HTML generated by a renderable, and the accompanying CSS that is required to make it display properly. The HTML is coded in the renderer - and then the CSS is added, either directly to the styles.css for the plugin in an unorganised way - or directly in the CSS in the theme - again in a loosely organised way. There is no systematic way to determine if any line of CSS is still in use - and there is no simple way to find the CSS that requires updating when the HTML is updated.
2. The CSS framework (bootstrap 2, bootstrap 3, zurb, pureio) specific attributes for renderables are currently being hardcoded in the HTML generated by the renderables. This prevents themers from using a different framework without creating an impossible amount of work to overwrite every renderer in Moodle.
So what is the problem
There are several. Lets be blunt about this. This specification is not a single task. It is about improving the state of output in Moodle and there are going to be several steps in achieving this. On a positive note these steps can in many cases be broken down into granular tasks that can be worked on asynchronously. First lets understand some of the major problems:
- We have no established best practices, nor even documentation on what constitutes a good renderer, or considerations that should be paid mind in planning and designing of code.
- We have no established style guide, nor pattern library, nor element library, nor anything that could be referenced when someone starts building a new user interface - or creating a new theme.
- Inconsistency - because of a lack of best practice documentation and examples, there is huge variation in the design of our different modules. Different modules exhibit different problems such as a mixing of logic and output and code duplication.
- Developers are encouraged to push functionality boundaries in order to take it places observed in other projects or to challenge oneself. While consistency is often talked about it is rarely observed when designing output. We end up with numerous "similar" looking widgets all functioning slightly differently and consequently there is a feeling that this is the way to achieve a new fresh look. (E.g. we have multiple implementations of a "toolbar" - one in Atto and one in EditPDF).
- Existing renderer implementations vary widely and in many cases contain logic they should not. Access checks, database queries, object manipulations. All of which should not be present as it introduces muddling of concepts and logic that must be duplicated and then maintained for anyone overriding renderers.
- Themers have a mammoth task at present in applying a consistent style to Moodle, or in choosing to implement a new frontend framework (bootstrap, foundation, pureio etc). Our lack of organisation in the output leaves a lot to be desired. Having the theme responsible for choosing a frontend framework is the right way to handle this, however backend Moodle doesn't support themeing as well as it should be/could be.
- On top of the above it introduces a need to override several renderers should you want to create a consistent style and because of inconsistent renderer implementations this can easily lead to a maintenance nightmare. E.g. the user_picture renderable is not used in mod_forum - so there is no way to override it there.
- JavaScript introduces problems of its own. We are doing more and more with JavaScript these days. However there is a heavy dependence on the output that gets produced and the JavaScript enhancing it. In a lot of cases the relationship is ill defined and due to the complexity and structure of the JavaScript overriding the output structure of the rendered component is completely impossible for all but the most experienced developers.
- Inline with the above we lack good examples and documentation on how to deliver output templates for JavaScript User Interfaces as well as the creation, and manipulation of HTML structures that are enhanced by JavaScript.
Identified issues
There is a general trend in the problems noted, when looking at output we lack organisation, documentation, and consistency across the board. However the actual issues we are focusing on in this spec can be identified as below:
- Lack of a style guide / element library / pattern library.
- Leading to inconsistent output and style.
- Increased workload due to usability and accessibility thinking and testing needing to occur repetitively.
- Increased workload due to multilang (rtl) support usually coming after the designs of new output.
- Inconsistent renderer implementations.
- Lack of best practices.
- Lacking plus outdated documentation.
- Logic-full renderers greatly hinder theming.
- An unnecessarily increased requirement to understand both PHP and Moodle code as each renderer differs and are usually poorly documented.
- No abstraction from CSS framework.
- Without organised structure classes are applied in a chaotic fashion leading to the requirement to duplicate core styles.
- As there is no core styles newly created output widgets need to be styled in all base themes leaving chance of design regressions occurring in predominantly major upgrades but occasionally minor releases as well.
- Inconsistent output structure ensures CSS quickly balloons as styles need to be both created and copied to several areas.
- Poor linking between UI components and the JavaScript.
- Ill-defined link between output and the JavaScript enhancing it.
- No common technique to template UIs generated by javascript
Manageable Tasks
The following are the major tasks we have identified so far. These tasks can be though of as Epic's, or tasks for which we will create subtasks (if this output specification itself becomes an Epic). Within this section will include notes and implementation ideas on the major tasks we've identified.
- Choose an output methodology and begin defining core elements
- Create an element library and accompanying style guide
- Create a style guide document
- Define and document renderer best practices
- Update the JavaScript documentation
- Update renderer documentation
- Update theme documentation and theme tutorials
- Progressively convert renderers
Define the elements that make up Moodle
There are several tasks that will go into this, but the first and most important will be deciding upon an organisational methodology. Some way to compartmentalise the Moodle output. At present a reducing granularity system is looking the most appealing. Go and read Atomic Design written by Brad Frost - it describes very well the type of compartmentalisation we are proposing.
Once a system has being chosen the following tasks can be tackled:
- Identify the layers we require.
- Define the boundaries and responsibilities of those layers.
- Identify the initial set of elements, likely the finest granularity first as I imagine starting at the bottom and working up will be the best way to proceed.
Further elements (those relating to Moodle will be defined as part of the element library work).
Element library and style guide
Draft docs for element library tool: Element_Library
Add an admin tool that can show a categorised list of renderable objects for each plugin/and core - filled with test data. The goal of this tool is to:
- Provide a page for themers to check that their new theme correctly displays all the renderables
- Provide a page for developers to see all the reusable renderables (in a well defined structure) they can use when building their own pages
The tasks here will be:
- Spec the element library tool with regard to our chosen element methodology.
- Create the element library tool.
- Establish a definition method of elements, and compositions of elements as renderables.
- Define the core elements from the task above in code somehow and verify the element library tool reveals them.
- Finally define a comprehensive list of low level widgets we can add to core as renderables. This is a library of components that should be used by other renderers (by compositing them). E.g. list, table, warning, grid. These renderables should be structured into layers, starting from renderables that cannot be broken into smaller parts, up to widgets made of smaller renderables, up to layouts (and possibly up to entire pages). Sources for this list should come from:
- Existing CSS Frameworks (bootstrap, pureio) (but must be framework agnostic)
- Existing renderables in Moodle that we see as “perfect” already (maybe there are some)
- Existing patterns in Moodle that we do over and over but don’t have a renderable for yet
On top of this there is functionality that would be great to add to it:
- Validate that the renderer/renderable follows best practice (no DB queries, complex types, complex logic)
- Provide responsive testing immediately within the tool. Adjusting the viewing area on queue to allow both developers and designers to experience how the individual renderables respond in varying presentation medias.
- Provide language direction testing immediately within the tool. Like the above allow designers and developers to quickly experience a renderable in a different language directions.
- Renderable linear reporting. So that you can see which other renderables make use of this renderable and which renderables get used by this renderable. This will be hugely helpful in judging impact when themeing.
Thoughts on naming
We will need to define useful names for the different categories of renderables so that we can effectively organise them and provide guidelines for writing each type - the names are a small part of this solution but will possibly be a point for contention. Different frameworks have different names for these things and people will prefer something that sounds like something they are already using.
(draft!) Categories for renderables - taken straight from Atomic design
http://bradfrostweb.com/blog/post/atomic-web-design/
- Atoms == Tiny reusable elements that cannot be broken down into smaller elements
- Molecules == Relatively simple combinations of atoms built for reuse
- Organisms == Organisms are groups of molecules joined together to form a relatively complex, distinct section of an interface.
- Templates == Layout files in a theme
- Pages == The actual pages in Moodle
Refs for categorizing patterns
- http://bradfrostweb.com/blog/post/atomic-web-design/
- http://oocss.org/
- http://alistapart.com/blog/post/getting-started-with-pattern-libraries
- http://style.codeforamerica.org/
Style guide
This has two real advantages.
- First assuming this will be developed initially while defining the elements that will make up Moodle output and will aid us in verifying what we are doing. If it can be easily documented then we are on the right track. If we start encountering to many conditions and or too much variation then we are drifting off track.
- When defining new elements we are able to use our style guide to do so and it'll provide us measure of how Moodle output evolves.
Define and document renderer best practices
This will be tricky and no doubt how we decide to define a best practice will have to have regard for the output methodology we choose.
Update the JavaScript documentation
Discuss and agree on a best practice for writing JS that depends on HTML structures in the DOM (e.g. progressive enhancement - or just ids for action listeners) (perhaps a specific renderable for a JS region)
Update renderer documentation
This will of course need to be done after the element library and renderer best practices but should be pretty simple at that point.
- Read and rate each of the existing docs pages (see related links below)
- Write new complete docs for everyone (at Output API)
- Cross link old docs to the new ones
Update theme documentation and theme tutorials
There are likely the most well documented plugin type within Moodle. There are good specification docs, good 2.0 conversion docs and good tutorials on many aspects of theming. Many of these pages will need to be updated to reflect best practices and such after we start ticking off some of the other tasks.
Progressively convert renderers
This is the very last task really - but we will start work on it in parallel with creating the new set of core renderables (to prove the design is usable). There is no deadline for this to be complete - and it will take a long time to convert all the existing renderers (and code not using renderers).
Notes on renderers / renderables
Proposed improvements to the docs on renderers / renderables. First - the docs need an overhaul to more clearly explain how renderers / renderables work for core devs, plugin devs and themers. There needs to be clearer guidelines for the things that can be done in a renderable, and in a renderer.
Goals for renderers - should be devoid of logic for these reasons:
- Theme overridden renderers do not need to be updated when logic is changed
- Themers can override renderers without understanding all the logic
- Renderables can be filled with mock data for display in the element library
A "good renderer" is:
- Receives some “data” through a renderable
- Produces some “output”
- Where “output” is some HTML and any javascript init calls
- Can use basic PHP functions/loops, like for(), foreach(), count()
A "good renderer" is not:
- nasty php logic (or even non-nasty php logic)
- access checks
- non-trivial function calls
- using any Moodle functions not related to output
- calling the database
A “renderable” is:
- All the data required to generate the output.
- Properties should be simple data types only, or renderables, or array of those
Evaluations of some existing renderers / renderables
Existing renderer styles - because there are few rules/guidelines for how renderers should be written - there are differing examples of renderers in core. Looking at the 3 of the better maintained modules to see how they are implemented will be useful in evaluating the benefits of any stricter rules for renderers.
Assign
Contains a list of renderables (in renderables.php) and a single renderer. The logic is mostly out of the renderer methods (pre-calculated and added as data to the renderer). There are some cases when renderables could be broken down further - e.g. the expand/collapse on the submission history (mod/assign/yui/src/history/js/history.js). Also the assignment sub-plugins do not use renderers (and they should).
Quiz
Uses a lot of renderers - but not renderables. The renderer methods directly call methods of the business logic to determine what to display. e.g. "attemptobj->get_access_manager(time())->attempt_must_be_in_popup()". This is not terrible for a themer trying to override a renderer method because the calls are mostly simple - but it is a grey area for when this becomes business logic in the renderer (and would e.g. need updating to fix bugs etc). If we want to add these renderer methods to the element library - it would require a way to pass mock business logic classes to the renderer methods (and a way for the generator to return a renderer and a method - instead of only a renderable).
Workshop
Very nice renderers and renderables in workshop. Would only need updating to re-use core renderables instead of using html_writer directly - and adding the existing renderables to the element library.
Badges
Mix of renderer methods and renderables. This is similar to quiz where the renderer is calling lots of methods of the business model in the renderer methods and has the same effect (harder to override, maintain etc). To add these renderer methods to the element library would require the same sort of changes as mentioned in quiz.
Example of forum post renderer using composition
This is not a real example (yet), it's just a demonstration of the type of renderers we should be aiming for (using composition etc). This structure would be created in the render_form_post method of the forum renderer. This method would receive a forum_post renderable containing only data - and build up this structure of smaller renderable components, then return the result of calling render(x) on each of the smaller renderables.
Initial thoughts on renderables and what we should provide (Draft)
This list is not intended to be the final list - it is more of a scoping exercise. One of the tasks from this project is to decide on the full set of required renderables. There are several renderables within Moodle that have being included in this table and we will need to look closely at how they fit within our chosen model and whether they are still required.
| Name | Description | Source (links) |
|---|---|---|
| action_menu | UI component for a drop down edit menu | Existing renderable (should be renamed "menu") |
| action_menu_link | UI component for a menu item in an action menu | Existing renderable |
| action_menu_filler | UI component for a filler menu item in an action menu | Existing renderable |
| action_menu_link_primary | UI component for a primary menu item in an action menu | Existing renderable |
| action_menu_link_secondary | UI component for a secondary menu item in an action menu | Existing renderable |
| action_link | Link with alt text, and an icon | Existing renderable |
| single_button | A form with a single button | Existing renderable |
| confirm | A form with a message and cancel/confirm buttons | Existing renderable |
| single_select | A form with a single drop down list that submits on change | Existing renderable |
| url_select | A navigation element consisting of a single drop down list of urls that navigates on change | Existing renderable |
| doc_link | A link to the Moodle docs | Existing renderer method |
| pix_icon | A small icon | Existing renderable |
| emoticon_icon | A small emoticon | Existing renderable |
| heading_with_help | A page heading with a link to help docs | Existing renderer method |
| help_icon | A help icon that opens a help popup when clicked | Existing renderable |
| help_icon_scale | A help icon that opens a help popup when clicked | Existing renderable |
| user_picture | A user profile picture which links to their profile | Existing renderable |
| container | A block level element used to surround something. Can have a class to allow specific targeting with CSS. | Existing renderable |
| error_text | An error to show to the user. | Existing renderable |
| notification | A message for the user | Existing renderable |
| continue_button | A message and a button to continue to the next page | Existing renderable |
| paging_bar | A list of next previous and specific page links | Existing renderable |
| skip_link_to | A link to a section on the page | Existing renderable |
| skip_link_target | A target for a matching skip_link_to call | Existing renderable |
| heading | A page heading | Existing renderable |
| box | A page section with a border | Existing renderable |
| rarrow | A right arrow | Existing renderable |
| larrow | A left arrow | Existing renderable |
| tabtree | A list of tabs | Existing renderable |
| tabobject | A single tab panel | Existing renderable |
| toolbar *new | A container for toolbar button groups | Bootstrap equiv btn-toolbar (needs aria support) |
| toolbar-group *new | A group of toolbar buttons | Bootstrap equiv btn-group (needs aria support) |
| toolbar-button *new | A toolbar button | Bootstrap equiv btn (needs aria support) |
| toolbar-menu *new | A toolbar button that opens a drop down menu | Bootstrap equiv nested btn-groups (needs aria support) |
| navbar *new | The navigation bar that shows at the top of the page | Bootstrap equiv navbar - There is an existing renderer method that needs converting into renderables |
| navbar_item *new | Items in the navigation bar that shows at the top of the page | Bootstrap equiv list item in a navbar - There is an existing renderer method that needs converting into renderables |
| navbar_item *new | Items in the navigation bar that shows at the top of the page | Bootstrap equiv list item in a navbar - There is an existing renderer method that needs converting into renderables |
| progress_bar *new | A bar showing progress of something | Bootstrap equiv progress_bar - There is an existing moodle class that needs converting to use renderables |
| progress_bar *new | A bar showing progress of something | Bootstrap equiv progress_bar - There is an existing moodle class that needs converting to use renderables |
| panel *new | A container with a heading and borders | Bootstrap equiv panel, panel-heading, panel-body, panel-footer |
| vertical-list *new | A vertical list of items | Bootstrap equiv - list-group |
| horizontal-list *new | A horizontal list of items | Bootstrap equiv - list-inline |
| Two column list *new | Short cut for a list of pairs with the left column fixed-width and right aligned | Similar to our current moodle forms |
| table (and cells headings etc) * new | We need to convert tablelib to use renderers to output all table elements | |
| forms (and labels, inputs etc) * new | We need to convert formslib to use renderers to output all form elements | |
| grids *new | We need to support renderables for a simple responsive grid system | Everything has grids... |
| floats *new | We need to support floating elements left and right | Bootstrap - pull-left, pull-right |
| clearfix *new | If we have this simple thing as a renderable we can avoid repeating the CSS | Bootstrap - clearfix |
| expandable *new | Initially shows only a summary with an expand button to show more details | mod_assign |
| dialog *new | Tie into M.core.dialogue so it can be adjusted in a renderer | aria |
| timer *new | There is an aria role for this - so we should make sure it is used correctly if required. | aria |
| tree *new | Reusable version of the nav tree | aria tree, tree-item, tree-grid etc |
| indent *new | (eg threaded forum post) | |
| media block *new | large media element side by side with some text | http://demo.patternlab.io/ |
| hero *new | content section with borders/oversized text etc designed to be a landing point | Bootstrap jumbotron |
Prototyping
We built a lot of prototypes here - trying to find the perfect solution - but even the most elegant PHP class design still means that the renderer is hard to build and understand.
List of corpses :)
https://github.com/samhemelryk/moodle/tree/output_prototype https://github.com/samhemelryk/moodle/tree/output_prototype2 https://github.com/samhemelryk/moodle/tree/output_prototype3 https://github.com/samhemelryk/moodle/tree/output_prototype5 https://github.com/samhemelryk/moodle/tree/output_prototype2 https://github.com/damyon/moodle/tree/MENU_RENDERABLE
We also tried to explain the importance of separating logic from renderer methods - but there were gray areas when people asked about simple capability checks, calling helper methods etc.
The new proposal is to add support for mustache templates to renderers and build support so they can be used from Javascript or PHP.
Mustache
What is Mustache and why does this hipster want to climb in my renderables ?
Mustache is a templating library designed to use "Logic-less templates". It is very popular with Javascript developers.
Side note: Handlebars is an alternative to mustache that builds on the mustache syntax with more features, but unfortunately the php implementation of handlebars is unreliable and does not conform to the specification (I tested). Handlebars also allows more logic to leak into the templates (function calls with params etc) and I found it led to more mess.
Question: How does it work in Moodle?
Answer: Really well! Say I have a renderable called "foobar". Instead of defining a function in my renderer named render_foobar($foobar), I just create a file in the templates folder for my plugin named foobar.mustache. A mustache template contains real HTML and mustache tags and nothing else. My new template will be rendered using the renderable as the context.
What Mustache Cannot Do
Well - things that resemble logic (and it's designed that way). Mustache is intentionally really strict about what you can and can't do in a template. The surprising thing is that it cannot do even simple calculations. You can't say "if now < due date" or "if can_access(blah)" or anything like that. Booleans need to be evaluated when the renderable is created and stored as data. This is what makes the templates free of logic and portable.
Mustache Examples
Old renderer method:
public function render_assign_grading_summary(assign_grading_summary $summary) {
// Create a table for the data.
$o = ;
$o .= $this->output->container_start('gradingsummary');
$o .= $this->output->heading(get_string('gradingsummary', 'assign'), 3);
$o .= $this->output->box_start('boxaligncenter gradingsummarytable');
$t = new html_table();
// Status.
if ($summary->teamsubmission) {
$this->add_table_row_tuple($t, get_string('numberofteams', 'assign'),
$summary->participantcount);
} else {
$this->add_table_row_tuple($t, get_string('numberofparticipants', 'assign'),
$summary->participantcount);
}
// Drafts count and dont show drafts count when using offline assignment.
if ($summary->submissiondraftsenabled && $summary->submissionsenabled) {
$this->add_table_row_tuple($t, get_string('numberofdraftsubmissions', 'assign'),
$summary->submissiondraftscount);
}
// Submitted for grading.
if ($summary->submissionsenabled) {
$this->add_table_row_tuple($t, get_string('numberofsubmittedassignments', 'assign'),
$summary->submissionssubmittedcount);
if (!$summary->teamsubmission) {
$this->add_table_row_tuple($t, get_string('numberofsubmissionsneedgrading', 'assign'),
$summary->submissionsneedgradingcount);
}
}
$time = time();
if ($summary->duedate) {
// Due date.
$duedate = $summary->duedate;
$this->add_table_row_tuple($t, get_string('duedate', 'assign'),
userdate($duedate));
// Time remaining.
$due = ;
if ($duedate - $time <= 0) {
$due = get_string('assignmentisdue', 'assign');
} else {
$due = format_time($duedate - $time);
}
$this->add_table_row_tuple($t, get_string('timeremaining', 'assign'), $due);
if ($duedate < $time) {
$cutoffdate = $summary->cutoffdate;
if ($cutoffdate) {
if ($cutoffdate > $time) {
$late = get_string('latesubmissionsaccepted', 'assign');
} else {
$late = get_string('nomoresubmissionsaccepted', 'assign');
}
$this->add_table_row_tuple($t, get_string('latesubmissions', 'assign'), $late);
}
}
}
// All done - write the table.
$o .= html_writer::table($t);
$o .= $this->output->box_end();
// Link to the grading page.
$o .= $this->output->container_start('submissionlinks');
$urlparams = array('id' => $summary->coursemoduleid, 'action'=>'grading');
$url = new moodle_url('/mod/assign/view.php', $urlparams);
$o .= $this->output->action_link($url, get_string('viewgrading', 'assign'));
$o .= $this->output->container_end();
// Close the container and insert a spacer.
$o .= $this->output->container_end();
return $o;
}
New mustache template:
Template:str.mod assign.gradingsummary
<tbody>
{{#submissionsenabled}}
{{#submissiondraftsenabled}}
Template:/submissiondraftsenabledTemplate:^teamsubmissionTemplate:/teamsubmissionTemplate:/submissionsenabled
{{#duedate}}
{{#late}}
Template:/late
Template:^late
Template:/late
{{#late}}
{{#latesubmissionaccepted}}
Template:/latesubmissionaccepted
Template:^latesubmissionaccepted
Template:/latesubmissionaccepted
Template:/lateTemplate:/duedate
</tbody>
{{#links}}
{{.}}
Template:/links
A themer could much more easily modify this HTML by copying the template into their themes templates directly and editing it, than by creating a renderer and changing php code.
Documents created as part of this spec
- Output element planning - Thoughts on initial elements that should be created.
- Renderer best practices
- Guide to creating output elements
- Element HTML and CSS guidelines
