block_editor_rest_api_preload( (string|string[])[] $preload_paths, WP_Block_Editor_Context $block_editor_context )

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$preload_paths(string|string[])[]

List of paths to preload.

$block_editor_contextWP_Block_Editor_Context

The current block editor context.

Performance profile

How much work a call to block_editor_rest_api_preload() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Light

Touches nothing outside its own arguments.

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

16–66

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 90.

Plugin surface

2 hooks

Third-party callbacks on 'block_editor_rest_api_preload_paths', 'block_editor_preload_paths' run inside this call, and their cost is not bounded by anything here.

Called by

0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

• hookthird-party callbacksapply_filters()called directly

Further down the call graph this can also reach option, cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 2 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost block_editor_rest_api_preload() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 2

2 hooks fire while block_editor_rest_api_preload() runs, in this order:

1. 1
   apply_filters( block_editor_rest_api_preload_paths )filterline 691 (+11 into the body)

   Filters the array of REST API paths that will be used to preloaded common data for the block editor.

2. 2
   do_action( block_editor_preload_paths )filter_deprecatedline 707 (+27 into the body)

   Filters the array of paths that will be preloaded.

Uses · 5

• apply_filters()Calls the callback functions that have been added to a filter hook.
• apply_filters_deprecated()Fires functions attached to a deprecated filter hook.
• str_starts_with()Polyfill for `str_starts_with()` function added in PHP 8.0.
• wp_add_inline_script()Adds extra code to a registered script.
• wp_json_encode()Encodes a variable into JSON, with some confidence checks.

Source code

View on Trac ↗View on GitHub ↗

680function block_editor_rest_api_preload( array $preload_paths, $block_editor_context ) {681	global $post, $wp_scripts, $wp_styles;682 683	/**684	 * Filters the array of REST API paths that will be used to preloaded common data for the block editor.685	 *686	 * @since 5.8.0687	 *688	 * @param (string|string[])[]     $preload_paths        Array of paths to preload.689	 * @param WP_Block_Editor_Context $block_editor_context The current block editor context.690	 */691	$preload_paths = apply_filters( 'block_editor_rest_api_preload_paths', $preload_paths, $block_editor_context );692 693	if ( ! empty( $block_editor_context->post ) ) {694		$selected_post = $block_editor_context->post;695 696		/**697		 * Filters the array of paths that will be preloaded.698		 *699		 * Preload common data by specifying an array of REST API paths that will be preloaded.700		 *701		 * @since 5.0.0702		 * @deprecated 5.8.0 Use the {@see 'block_editor_rest_api_preload_paths'} filter instead.703		 *704		 * @param (string|string[])[] $preload_paths Array of paths to preload.705		 * @param WP_Post             $selected_post Post being edited.706		 */707		$preload_paths = apply_filters_deprecated( 'block_editor_preload_paths', array( $preload_paths, $selected_post ), '5.8.0', 'block_editor_rest_api_preload_paths' );708	}709 710	if ( empty( $preload_paths ) ) {711		return;712	}713 714	/*715	 * Ensure the global $post, $wp_scripts, and $wp_styles remain the same after716	 * API data is preloaded.717	 * Because API preloading can call the_content and other filters, plugins718	 * can unexpectedly modify the global $post or enqueue assets which are not719	 * intended for the block editor.720	 */721	$backup_global_post = ! empty( $post ) ? clone $post : $post;722	$backup_wp_scripts  = ! empty( $wp_scripts ) ? clone $wp_scripts : $wp_scripts;723	$backup_wp_styles   = ! empty( $wp_styles ) ? clone $wp_styles : $wp_styles;724 725	foreach ( $preload_paths as &$path ) {726		if ( is_string( $path ) && ! str_starts_with( $path, '/' ) ) {727			$path = '/' . $path;728			continue;729		}730 731		if ( is_array( $path ) && is_string( $path[0] ) && ! str_starts_with( $path[0], '/' ) ) {732			$path[0] = '/' . $path[0];733		}734	}735 736	unset( $path );737 738	$preload_data = array_reduce(739		$preload_paths,740		'rest_preload_api_request',741		array()742	);743 744	// Restore the global $post, $wp_scripts, and $wp_styles as they were before API preloading.745	$post       = $backup_global_post;746	$wp_scripts = $backup_wp_scripts;747	$wp_styles  = $backup_wp_styles;748 749	wp_add_inline_script(750		'wp-api-fetch',751		sprintf(752			'wp.apiFetch.use( wp.apiFetch.createPreloadingMiddleware( %s ) );',753			wp_json_encode( $preload_data, JSON_HEX_TAG | JSON_UNESCAPED_SLASHES )754		),755		'after'756	);757}

Changelog

Introduced in 5.8.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/block-editor.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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