<?php
/**
* Server-side rendering of the `core/accordion-item` block.
*
* @package WordPress
* @since 6.9.0
*
* @param array{ openByDefault: bool } $attributes The block attributes.
* @param string $content The block content.
* @return string Returns the updated markup.
*/
function block_core_accordion_item_render( array $attributes, string $content ): string {
if ( '' === $content ) {
return $content;
}
$p = new WP_HTML_Tag_Processor( $content );
$unique_id = wp_unique_id( 'accordion-item-' );
// Initialize the state of the item on the server using a closure,
// since we need to get derived state based on the current context.
wp_interactivity_state(
'core/accordion',
array(
'isOpen' => function () {
$context = wp_interactivity_get_context();
return $context['openByDefault'];
},
)
);
if ( $p->next_tag( array( 'class_name' => 'wp-block-accordion-item' ) ) ) {
$open_by_default = $attributes['openByDefault'] ? 'true' : 'false';
$p->set_attribute( 'data-wp-context', '{ "id": "' . $unique_id . '", "openByDefault": ' . $open_by_default . ' }' );
$p->set_attribute( 'data-wp-class--is-open', 'state.isOpen' );
$p->set_attribute( 'data-wp-init', 'callbacks.initAccordionItems' );
$p->set_attribute( 'data-wp-on-window--hashchange', 'callbacks.hashChange' );
if ( $p->next_tag( array( 'class_name' => 'wp-block-accordion-heading__toggle' ) ) ) {
$p->set_attribute( 'data-wp-on--click', 'actions.toggle' );
$p->set_attribute( 'id', $unique_id );
$p->set_attribute( 'aria-controls', $unique_id . '-panel' );
$p->set_attribute( 'data-wp-bind--aria-expanded', 'state.isOpen' );
if ( $p->next_tag( array( 'class_name' => 'wp-block-accordion-panel' ) ) ) {
$p->set_attribute( 'id', $unique_id . '-panel' );
$p->set_attribute( 'aria-labelledby', $unique_id );
$p->set_attribute( 'data-wp-bind--hidden', 'state.isHidden' );
$p->set_attribute( 'data-wp-on--beforematch', 'actions.handleBeforeMatch' );
// Only modify content if all directives have been set.
$content = $p->get_updated_html();
}
}
}
/*
* If an Accordion Item is collapsed by default, ensure any contained IMG has fetchpriority=low to deprioritize it
* from contending with resources in the critical rendering path. In contrast, remove the loading attribute to
* prevent the image from not being available when the item is expanded.
*/
if ( ! $attributes['openByDefault'] ) {
$processor = new WP_HTML_Tag_Processor( $content );
while ( $processor->next_tag( 'IMG' ) ) {
$processor->set_attribute( 'fetchpriority', 'low' );
}
$content = $processor->get_updated_html();
}
return $content;
}
/**
* Registers the `core/accordion-item` block on server.
*
* @since 6.9.0
*/
function register_block_core_accordion_item() {
register_block_type_from_metadata(
__DIR__ . '/accordion-item',
array(
'render_callback' => 'block_core_accordion_item_render',
)
);
}
add_action( 'init', 'register_block_core_accordion_item' );