Add Collapsible Categories v1 to Extensions

This page contains documentation for the discontinued 1.x.x versions of Collapsible Categories. Refer to the V2 documentation for the current version of Collapsible Categories.

Adding Collapsible Forum Categories to an existing extension is easy for an extension author to achieve.

Collapsible Categories (CC) is based around the structure of phpBB Prosilver’s forum category layout. That’s the element with the forabg class and the content to be hidden inside the element with the topiclist forums classes.

This guide will use the Welcome on Index (WOI) extension by Stoker as an example.

It should be just as easy to modify any other applicable extension, such as MChat or Shoutbox, by referencing this guide. The main modifications are:

• Add our template code to your template
• Add our php code to populate the new template variables
• Update the services.yml with the new dependency variables

The Template Code

CC’s template events are designed for the forumrow loop and can not be used by WOI. WOI displays a single (non-looped) forabg element on the index page, so we need to hard code some template code into the WOI index_body_mark_forums_before.html file, loosely based on what is in CC’s template events.

Add the following anchor point just before <div class="forabg"> so you have:

<a class="category<!-- IF S_FOO_HIDDEN --> hidden-category<!-- ENDIF -->" style="display: none; height: 0"></a>
<div class="forabg">

Notice that it has a custom variable S_FOO_HIDDEN. It can be renamed to whatever makes sense for your extension.

Next add the button code after the first closing <dl> tag, so you have something like:

<dl class="icon">
	<dt><div class="list-inner" style="width:90%;">{L_WELCOME_TO_MOD} {SITENAME}</div></dt>
</dl>
<a href="{U_FOO_COLLAPSE_URL}" 
    class="collapse-btn collapse-<!-- IF S_FOO_HIDDEN -->show<!-- ELSE -->hide<!-- ENDIF -->" 
    data-hidden="{S_FOO_HIDDEN}" 
    data-ajax="phpbb_collapse" 
    data-overlay="true" 
    title="{L_COLLAPSIBLE_CATEGORIES_TITLE}" 
    style="display: none; line-height: 0;"></a>

Notice the custom variables S_FOO_HIDDEN and U_FOO_COLLAPSE_URL which will need to be set next.

If the element being collapsed does not have both the classes topiclist forums then you must add the class collapsible to the element that is being collapsed/expanded. For example, the MCHAT extension would be changed to:

<div class="postbody mChatBodyFix collapsible">

The Event Listener

Now we need to assign the two template variables U_FOO_COLLAPSE_URL and S_FOO_HIDDEN.

We can use WOI’s main() function in the event.php class to assign these variables. We will also be needing the $template and CC’s $operator objects, so they need to be added to the class constructor as dependencies (if not already there). The $operator object from CC will need to be optional, so it should be defined at the end of the arguments list with a default value of null.

The constructor should look like:

public function __construct(
    \stoker\welcomeonindex\core\functions_welcomeonindex $functions,
    \phpbb\template\template $template,
    \phpbb\collapsiblecategories\operator\operator $operator = null
)
{
    $this->welcomeonindex_functions = $functions;
    $this->template = $template;
    $this->operator = $operator;
}

Now we can add the following code to WOI’s main() function:

if ($this->operator !== null)
{
    $fid = 'foo_1'; // can be any unique string to identify your extension's collapsible element
    $this->template->assign_vars(array(
        'S_FOO_HIDDEN'       => $this->operator->is_collapsed($fid),
        'U_FOO_COLLAPSE_URL' => $this->operator->get_collapsible_link($fid),
    ));
}

Notice that our code is wrapped in a conditional. This is very important and means that this code will only run if CC is installed and properly loaded.

The services.yml

Finally, the services.yml needs to be updated with the additional dependencies we added to the event class constructor. Special note should be paid to the CC operator class, which is made optional by adding a ? to it:

stoker.welcomeonindex.listener:
    class: stoker\welcomeonindex\event\listener
    arguments:
        - '@stoker.welcomeonindex.functions'
        - '@template'
        - '@?phpbb.collapsiblecategories.operator'
    tags:
        - { name: 'event.listener' }

With just those few minor modifications, CC will be integrated into WOI.