wp_get_attachment_thumb_url( int $post_id = 0 ): string|false

Compatibility

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

Parameters

$post_idintoptional

Attachment ID. Default is the ID of the global $post.Default: 0

Return value

string|false

Thumbnail URL on success, false on failure.

Performance profile

How much work a call to wp_get_attachment_thumb_url() 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

Touches nothing outside its own arguments.

Scaling

Constant

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

Instructions

11–16

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 17.

Plugin surface

1 hook

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

Called by

1

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

What it touches

• hookthird-party callbacksapply_filters()called directly

Further down the call graph this can also reach cache, query, option, 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 · 2 distinct outcomes

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

Hooks and filters fired · 1

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

1. 1
   apply_filters( wp_get_attachment_thumb_url )filterline 7011 (+21 into the body)

   Filters the attachment thumbnail URL.

Uses · 2

• wp_get_attachment_image_url()Gets the URL of an image attachment.
• apply_filters()Calls the callback functions that have been added to a filter hook.

Used by · 1

• get_attachment_icon_src()Retrieve icon URL and Path.

Source code

View on Trac ↗View on GitHub ↗

6990function wp_get_attachment_thumb_url( $post_id = 0 ) {6991	$post_id = (int) $post_id;6992 6993	/*6994	 * This uses image_downsize() which also looks for the (very) old format $image_meta['thumb']6995	 * when the newer format $image_meta['sizes']['thumbnail'] doesn't exist.6996	 */6997	$thumbnail_url = wp_get_attachment_image_url( $post_id, 'thumbnail' );6998 6999	if ( empty( $thumbnail_url ) ) {7000		return false;7001	}7002 7003	/**7004	 * Filters the attachment thumbnail URL.7005	 *7006	 * @since 2.1.07007	 *7008	 * @param string $thumbnail_url URL for the attachment thumbnail.7009	 * @param int    $post_id       Attachment ID.7010	 */7011	return apply_filters( 'wp_get_attachment_thumb_url', $thumbnail_url, $post_id );7012}

Changelog

Introduced in 2.1.0. 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/post.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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