load_template( string $_template_file, bool $load_once = true, array $args = array() )
- Since
- 1.5.0, 5.5.0
- Source
wp-includes/template.php:782
Description
The globals are set up for the template file to ensure that the WordPress environment is available from within the function. The query variables are also available.
Compatibility
- WordPress
- since 5.5.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$_template_filestring- Path to template file.
$load_oncebooloptional- Whether to require_once or require. Default true.Default:
true $argsarrayoptional- Additional arguments passed to the template.
Default empty array.Default:array()
Performance profile
How much work a call to load_template() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 34–44
- Plugin surface
- 2 hooks
- Called by
- 5
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 45.
Third-party callbacks on 'wp_before_load_template', 'wp_after_load_template' run inside this call, and their cost is not bounded by anything here.
5 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
do_action()called directly
Further down the call graph this can also reach option, cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.
What one call costs · 4 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost load_template() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!isset($s) | 34–35 | do_action(), do_action() |
isset($s) | 38–39 | esc_attr(), do_action(), do_action() |
!isset($s) | 39–40 | extract(), do_action(), do_action() |
isset($s) | 43–44 | extract(), esc_attr(), do_action(), do_action() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 45 instructions, 34–44 executed per call, 3 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Hooks and filters fired · 2
2 hooks fire while load_template() runs, in this order:
- do_action( wp_before_load_template )actionline 811 (+29 into the body)
Fires before a template file is loaded.
- do_action( wp_after_load_template )actionline 828 (+46 into the body)
Fires after a template file is loaded.
Uses · 2
- esc_attr()Escaping for HTML attributes.
- do_action()Calls the callback functions that have been added to an action hook.
Used by · 5
- do_feed_atom()Loads either Atom comment feed or Atom posts feed.
- do_feed_rdf()Loads the RDF RSS 0.91 Feed template.
- do_feed_rss()Loads the RSS 1.0 Feed Template.
- do_feed_rss2()Loads either the RSS2 comment feed or the RSS2 posts feed.
- locate_template()Retrieves the name of the highest priority template file that exists.
Source code
function load_template( $_template_file, $load_once = true, $args = array() ) { global $posts, $post, $wp_did_header, $wp_query, $wp_rewrite, $wpdb, $wp_version, $wp, $id, $comment, $user_ID; if ( is_array( $wp_query->query_vars ) ) { /* * This use of extract() cannot be removed. There are many possible ways that * templates could depend on variables that it creates existing, and no way to * detect and deprecate it. * * Passing the EXTR_SKIP flag is the safest option, ensuring globals and * function variables cannot be overwritten. */ // phpcs:ignore WordPress.PHP.DontExtract.extract_extract extract( $wp_query->query_vars, EXTR_SKIP ); } if ( isset( $s ) ) { $s = esc_attr( $s ); // @phpstan-ignore variable.undefined (It's extracted from query vars.) } /** * Fires before a template file is loaded. * * @since 6.1.0 * * @param string $_template_file The full path to the template file. * @param bool $load_once Whether to require_once or require. * @param array $args Additional arguments passed to the template. */ do_action( 'wp_before_load_template', $_template_file, $load_once, $args ); if ( $load_once ) { require_once $_template_file; } else { require $_template_file; } /** * Fires after a template file is loaded. * * @since 6.1.0 * * @param string $_template_file The full path to the template file. * @param bool $load_once Whether to require_once or require. * @param array $args Additional arguments passed to the template. */ do_action( 'wp_after_load_template', $_template_file, $load_once, $args );}Changelog
Introduced in 1.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
$args parameter was added.from the docblockAbout 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
- Something wrong on this page? Report it and it gets fixed in the next regeneration.