locate_block_template( string $template, string $type, string[] $templates ): string

Description

Compatibility

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

Parameters

$templatestring

Path to the template. See locate_template().

$typestring

Sanitized filename without extension.

$templatesstring[]

A list of template candidates, in descending order of priority.

Return value

string

The path to the Site Editor template canvas file, or the fallback PHP template.

Performance profile

How much work a call to locate_block_template() 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

Heavy

Reads or writes the filesystem via file_get_contents().

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

10–89

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 118.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• filesystemfilesystem accessfile_get_contents()called directly
• hookthird-party callbacksapply_filters()one call below locate_block_template()

Further down the call graph this can also reach option, query, cache, serialize 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 · 21 distinct outcomes

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

Uses · 12

• current_theme_supports()Checks a theme's support for a given feature.
• get_stylesheet_directory()Retrieves stylesheet directory path for the active theme.
• get_template_directory()Retrieves template directory path for the active theme.
• resolve_block_template()Returns the correct 'wp_template' to render for the request template type.
• is_user_logged_in()Determines whether the current visitor is a logged in user.
• wp_render_empty_block_template_warning()Renders a warning screen for empty block templates.
• _get_block_template_file()Retrieves the template file from the theme for a given slug.
• wp_send_json_success()Sends a JSON response back to an Ajax request, indicating success.
• wp_send_json_error()Sends a JSON response back to an Ajax request, indicating failure.
• __()Retrieves the translation of $text.
• add_action()Adds a callback function to an action hook.
• remove_action()Removes a callback function from an action hook.

Used by · 1

• get_query_template()Retrieves path to a template.

Source code

View on Trac ↗View on GitHub ↗

62function locate_block_template( $template, $type, array $templates ) {63	global $_wp_current_template_content, $_wp_current_template_id;64 65	if ( ! current_theme_supports( 'block-templates' ) ) {66		return $template;67	}68 69	if ( $template ) {70		/*71		 * locate_template() has found a PHP template at the path specified by $template.72		 * That means that we have a fallback candidate if we cannot find a block template73		 * with higher specificity.74		 *75		 * Thus, before looking for matching block themes, we shorten our list of candidate76		 * templates accordingly.77		 */78 79		// Locate the index of $template (without the theme directory path) in $templates.80		$relative_template_path = str_replace(81			array( get_stylesheet_directory() . '/', get_template_directory() . '/' ),82			'',83			$template84		);85		$index                  = array_search( $relative_template_path, $templates, true );86 87		// If the template hierarchy algorithm has successfully located a PHP template file,88		// we will only consider block templates with higher or equal specificity.89		$templates = array_slice( $templates, 0, $index + 1 );90	}91 92	$block_template = resolve_block_template( $type, $templates, $template );93 94	if ( $block_template ) {95		$_wp_current_template_id = $block_template->id;96 97		if ( empty( $block_template->content ) ) {98			if ( is_user_logged_in() ) {99				$_wp_current_template_content = wp_render_empty_block_template_warning( $block_template );100			} else {101				if ( $block_template->has_theme_file ) {102					// Show contents from theme template if user is not logged in.103					$theme_template               = _get_block_template_file( 'wp_template', $block_template->slug );104					$_wp_current_template_content = file_get_contents( $theme_template['path'] );105				} else {106					$_wp_current_template_content = $block_template->content;107				}108			}109		} elseif ( ! empty( $block_template->content ) ) {110			$_wp_current_template_content = $block_template->content;111		}112		if ( isset( $_GET['_wp-find-template'] ) ) {113			wp_send_json_success( $block_template );114		}115	} else {116		if ( $template ) {117			return $template;118		}119 120		if ( 'index' === $type ) {121			if ( isset( $_GET['_wp-find-template'] ) ) {122				wp_send_json_error( array( 'message' => __( 'No matching template found.' ) ) );123			}124		} else {125			return ''; // So that the template loader keeps looking for templates.126		}127	}128 129	// Add hooks for template canvas.130	// Add viewport meta tag.131	add_action( 'wp_head', '_block_template_viewport_meta_tag', 0 );132 133	// Render title tag with content, regardless of whether theme has title-tag support.134	remove_action( 'wp_head', '_wp_render_title_tag', 1 );    // Remove conditional title tag rendering...135	add_action( 'wp_head', '_block_template_render_title_tag', 1 ); // ...and make it unconditional.136 137	// This file will be included instead of the theme's template file.138	return ABSPATH . WPINC . '/template-canvas.php';139}

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 6.8.8 tag, from src/wp-includes/block-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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