WP_Query::setup_postdata( WP_Post|object|int $post ): bool

Compatibility

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

Parameters

$postWP_Post|object|int

WP_Post instance or Post ID/object.

Return value

bool

True on success, false on failure.

Performance profile

How much work a call to WP_Query::setup_postdata() 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

Reaches the database via get_post().

Scaling

Constant

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

Instructions

14–49

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 51.

Plugin surface

1 hook

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

Called by

2

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

What it touches

• querycontent queryget_post()called directly
• hookthird-party callbacksdo_action_ref_array()called directly

Further down the call graph this can also reach option, 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 · 4 distinct outcomes

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

Hooks and filters fired · 1

One hook fires while WP_Query::setup_postdata() runs, in this order:

1. 1
   do_action( the_post )actionline 4860 (+35 into the body)

   Fires once the post data has been set up.

Uses · 3

• get_post()Retrieves post data given a post ID or post object.
• do_action_ref_array()Calls the callback functions that have been added to an action hook, specifying arguments in an array.
• WP_Query::generate_postdata()Generates post data.

Used by · 2

• WP_Query::reset_postdata()After looping through a nested query, this function restores the $post global to the current post in this query.
• WP_Query::the_post()Sets up the current post.

Source code

View on Trac ↗View on GitHub ↗

4825	public function setup_postdata( $post ) {4826		global $id, $authordata, $currentday, $currentmonth, $page, $pages, $multipage, $more, $numpages;4827 4828		if ( ! ( $post instanceof WP_Post ) ) {4829			$post = get_post( $post );4830		}4831 4832		if ( ! $post ) {4833			return false;4834		}4835 4836		$elements = $this->generate_postdata( $post );4837		if ( false === $elements ) {4838			return false;4839		}4840 4841		$id           = $elements['id'];4842		$authordata   = $elements['authordata'];4843		$currentday   = $elements['currentday'];4844		$currentmonth = $elements['currentmonth'];4845		$page         = $elements['page'];4846		$pages        = $elements['pages'];4847		$multipage    = $elements['multipage'];4848		$more         = $elements['more'];4849		$numpages     = $elements['numpages'];4850 4851		/**4852		 * Fires once the post data has been set up.4853		 *4854		 * @since 2.8.04855		 * @since 4.1.0 Introduced `$query` parameter.4856		 *4857		 * @param WP_Post  $post  The Post object (passed by reference).4858		 * @param WP_Query $query The current Query object (passed by reference).4859		 */4860		do_action_ref_array( 'the_post', array( &$post, &$this ) );4861 4862		return true;4863	}

Changelog

Introduced in 4.1.0. One change between 6.7.7 and 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 7.0.4 tag, from src/wp-includes/class-wp-query.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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