url_to_postid( string $url ): int

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

$urlstring

Permalink to check.

Return value

int

Post ID, or 0 on failure.

Performance profile

How much work a call to url_to_postid() 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

Scales with input

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

Instructions

77–222

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 296.

Plugin surface

1 hook

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

Called by

7

7 places 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
• optionoption read or writeget_option()called directly
• querycontent queryget_post()called directly
• cacheobject cachewp_cache_get()one call below url_to_postid()
• serializeserialisationmaybe_unserialize()one call below url_to_postid()

Further down the call graph this can also reach transient. That is the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 22 distinct outcomes

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

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Hooks and filters fired · 1

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

1. 1
   apply_filters( url_to_postid )filterline 500 (+10 into the body)

   Filters the URL to derive the post ID from.

Uses · 15

• apply_filters()Calls the callback functions that have been added to a filter hook.
• home_url()Retrieves the URL for the current site where the front end is accessible.
• absint()Converts a value to non-negative integer.
• set_url_scheme()Sets the scheme for a URL.
• str_contains()Polyfill for `str_contains()` function added in PHP 8.0.
• get_option()Retrieves an option value based on an option name.
• get_post()Retrieves post data given a post ID or post object.
• trailingslashit()Appends a trailing slash.
• get_post_types()Gets a list of all registered post type objects.
• str_starts_with()Polyfill for `str_starts_with()` function added in PHP 8.0.
• get_page_by_path()Retrieves a page given its path.
• get_post_status_object()Retrieves a post status object by name.

Used by · 7

• WP_oEmbed_Controller::get_item()Callback for the embed API endpoint.
• get_oembed_response_data_for_url()Retrieves the oEmbed response data for a given URL.
• is_local_attachment()Determines whether an attachment URI is local and really an attachment.
• pingback()Pings back the links found in a post.
• wp_xmlrpc_server::pingback_extensions_getPingbacks()Retrieves an array of URLs that pingbacked the given URL.
• wp_xmlrpc_server::pingback_ping()Retrieves a pingback and registers it.
• wp_xmlrpc_server::wp_newComment()Creates a new comment.

Source code

View on Trac ↗View on GitHub ↗

490function url_to_postid( $url ) {491	global $wp_rewrite;492 493	/**494	 * Filters the URL to derive the post ID from.495	 *496	 * @since 2.2.0497	 *498	 * @param string $url The URL to derive the post ID from.499	 */500	$url = apply_filters( 'url_to_postid', $url );501 502	$url_host = parse_url( $url, PHP_URL_HOST );503 504	if ( is_string( $url_host ) ) {505		$url_host = str_replace( 'www.', '', $url_host );506	} else {507		$url_host = '';508	}509 510	$home_url_host = parse_url( home_url(), PHP_URL_HOST );511 512	if ( is_string( $home_url_host ) ) {513		$home_url_host = str_replace( 'www.', '', $home_url_host );514	} else {515		$home_url_host = '';516	}517 518	// Bail early if the URL does not belong to this site.519	if ( $url_host && $url_host !== $home_url_host ) {520		return 0;521	}522 523	// First, check to see if there is a 'p=N' or 'page_id=N' to match against.524	if ( preg_match( '#[?&](p|page_id|attachment_id)=(\d+)#', $url, $values ) ) {525		$id = absint( $values[2] );526		if ( $id ) {527			return $id;528		}529	}530 531	// Get rid of the #anchor.532	$url_split = explode( '#', $url );533	$url       = $url_split[0];534 535	// Get rid of URL ?query=string.536	$url_split = explode( '?', $url );537	$url       = $url_split[0];538 539	// Set the correct URL scheme.540	$scheme = parse_url( home_url(), PHP_URL_SCHEME );541	$url    = set_url_scheme( $url, $scheme );542 543	// Add 'www.' if it is absent and should be there.544	if ( str_contains( home_url(), '://www.' ) && ! str_contains( $url, '://www.' ) ) {545		$url = str_replace( '://', '://www.', $url );546	}547 548	// Strip 'www.' if it is present and shouldn't be.549	if ( ! str_contains( home_url(), '://www.' ) ) {550		$url = str_replace( '://www.', '://', $url );551	}552 553	if ( trim( $url, '/' ) === home_url() && 'page' === get_option( 'show_on_front' ) ) {554		$page_on_front = get_option( 'page_on_front' );555 556		if ( $page_on_front && get_post( $page_on_front ) instanceof WP_Post ) {557			return (int) $page_on_front;558		}559	}560 561	// Check to see if we are using rewrite rules.562	$rewrite = $wp_rewrite->wp_rewrite_rules();563 564	// Not using rewrite rules, and 'p=N' and 'page_id=N' methods failed, so we're out of options.565	if ( empty( $rewrite ) ) {566		return 0;567	}568 569	// Strip 'index.php/' if we're not using path info permalinks.

Changelog

Introduced in 1.0.0. 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 6.9.7 tag, from src/wp-includes/rewrite.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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