locate_template( string|array $template_names, bool $load = false, bool $load_once = true, array $args = array() ): 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

$template_namesstring|array

Template file(s) to search for, in order.

$loadbooloptional

If true the template file will be loaded if it is found.Default: false

$load_oncebooloptional

Whether to require_once or require. Has no effect if $load is false.
Default true.Default: true

$argsarrayoptional

Additional arguments passed to the template.
Default empty array.Default: array()

Return value

string

The template filename if one is located.

Performance profile

How much work a call to locate_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_exists().

Scaling

Scales with input

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

Instructions

19–58

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 66.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

8

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

What it touches

• filesystemfilesystem accessfile_exists()called directly
• hookthird-party callbacksdo_action()one call below locate_template()

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

What one call costs · 16 distinct outcomes

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

Uses · 3

• wp_set_template_globals()Set up the globals used for template loading.
• is_child_theme()Whether a child theme is in use.
• load_template()Requires the template file with WordPress environment.

Used by · 8

• get_footer()Loads footer template.
• get_header()Loads header template.
• get_query_template()Retrieves path to a template.
• get_search_form()Displays search form.
• get_sidebar()Loads sidebar template.
• get_template_part()Loads a template part into a template.
• twentyfifteen_author_bio_template()Prevents `author-bio.php` partial template from interfering with rendering an author archive of a user with the `bio` username.
• twentythirteen_author_bio_template()Prevents `author-bio.php` partial template from interfering with rendering an author archive of a user with the `bio` username.

Source code

View on Trac ↗View on GitHub ↗

722function locate_template( $template_names, $load = false, $load_once = true, $args = array() ) {723	global $wp_stylesheet_path, $wp_template_path;724 725	if ( ! isset( $wp_stylesheet_path ) || ! isset( $wp_template_path ) ) {726		wp_set_template_globals();727	}728 729	$is_child_theme = is_child_theme();730 731	$located = '';732	foreach ( (array) $template_names as $template_name ) {733		if ( ! $template_name ) {734			continue;735		}736		if ( file_exists( $wp_stylesheet_path . '/' . $template_name ) ) {737			$located = $wp_stylesheet_path . '/' . $template_name;738			break;739		} elseif ( $is_child_theme && file_exists( $wp_template_path . '/' . $template_name ) ) {740			$located = $wp_template_path . '/' . $template_name;741			break;742		} elseif ( file_exists( ABSPATH . WPINC . '/theme-compat/' . $template_name ) ) {743			$located = ABSPATH . WPINC . '/theme-compat/' . $template_name;744			break;745		}746	}747 748	if ( $load && '' !== $located ) {749		load_template( $located, $load_once, $args );750	}751 752	return $located;753}

Changelog

Introduced in 2.7.0. 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/template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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