Scripts and styles

Plugins and themes load their own JavaScript and CSS through the enqueue functions rather than printing <script> tags. The point is deduplication: two plugins that both want the same library end up with one copy, in the right order, instead of two.

The functions

JavaScript

osc_register_script($id, $url, $dependencies = null);  // declare it exists
osc_enqueue_script($id);                               // actually load it
osc_unregister_script($id);                            // undeclare
osc_remove_script($id);                                // declared, but do not load
osc_enqueue_script_code($code, $dependencies = null, $id = null); // inline

CSS

osc_register_style($id, $url, $dependencies = null);
osc_enqueue_style($id, $url = null);                   // url optional if registered
osc_remove_style($id);

Registering says this asset exists, at this URL, and needs these things first. Enqueuing says this page needs it. Register once; enqueue wherever it is needed.

Where to hook

function myplugin_assets()
{
    osc_register_script(
        'myplugin-widget',
        osc_base_url() . 'oc-content/plugins/myplugin/js/widget.js'
    );
    osc_enqueue_script('myplugin-widget');

    osc_enqueue_style(
        'myplugin-css',
        osc_base_url() . 'oc-content/plugins/myplugin/css/widget.css'
    );
}

osc_add_hook('init', 'myplugin_assets');        // public site
osc_add_hook('init_admin', 'myplugin_assets');  // admin panel

jQuery is not loaded for you

This is the change that catches ported Osclass plugins.

Since 6.4, core no longer ships or registers jquery, jquery-ui or jquery-validate. A theme or plugin that uses them must ship its own copy.

The front end loads nothing by default, and the admin panel registers Bootstrap 5, not jQuery:

Registered in the admin	Depends on
bootstrap5	popper
popper	none
sortablejs	none
admin-osc, admin-ui-osc, admin-categories, admin-location	core admin behaviour

If your code needs jQuery, ship it and register it yourself:

osc_register_script('jquery', osc_base_url() . 'oc-content/plugins/myplugin/js/jquery.min.js');
osc_register_script('myplugin-widget', $url, 'jquery');
osc_enqueue_script('myplugin-widget');   // pulls jquery in first

Better: most of what plugins used jQuery for (selectors, fetch, class toggling, event delegation) is a few lines of plain JavaScript in a browser from the last decade. Dropping the dependency makes your plugin lighter and removes a class of version conflicts entirely.

Naming

The $id is a global namespace shared with every other plugin on the install.

• Prefix ids with your plugin folder: myplugin-widget, not widget.
• For a third-party library, use the library’s ordinary name: fancybox, chartjs, flatpickr. Two plugins registering the same library under the same id load it once; register it as my_strange_name and the visitor downloads it twice.

Location autocomplete without writing JavaScript

A theme that needs a country, region or city field does not have to write its own autocomplete. Core binds every input[data-ac] on the page to its own endpoints. Render the input, and nothing else.

<input type="text" name="city" id="city"
       data-ac="location_cities"
       data-ac-url="<?php echo osc_esc_html(osc_base_url(true)); ?>"
       data-ac-target="#cityId"
       data-ac-scope="#regionId"
       data-ac-scope-param="region">
<input type="hidden" name="cityId" id="cityId">

Attribute	What it is
data-ac	The endpoint: location_countries, location_regions or location_cities.
data-ac-url	Where to post. Always osc_base_url(true).
data-ac-target	Selector of the hidden input that receives the chosen row’s id.
data-ac-scope	Selector whose value narrows the search: the region, for a city.
data-ac-scope-param	The parameter name that value is sent as.
data-ac-clears	Comma-separated selectors emptied when this field changes.

The endpoints match on the first letters of a name and return {id, value} rows.

If your theme already ships its own binder, it wins the race and core’s becomes a no-op for that field, so adopting this is safe and can be done one field at a time.

Cache-busting

Append a version to your asset URL so an update actually reaches returning visitors instead of sitting behind their browser cache. Core does this with osc_asset_url_versioned().