wp_resource_hints()

Description

Hooks fired · 1

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

1. 1
   apply_filters( wp_resource_hints )filterline 3674 (+35 into the body)

   Filters domains and URLs for resource hints of the given relation type.

Uses · 5

• wp_dependencies_unique_hosts()Retrieves a list of unique hosts of all enqueued scripts and styles.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• esc_url()Checks and cleans a URL.
• wp_parse_url()A wrapper for PHP's parse_url() function that handles consistency in the return values across PHP versions.
• esc_attr()Escaping for HTML attributes.

Source

View on Trac ↗View on GitHub ↗

3639function wp_resource_hints() {3640	$hints = array(3641		'dns-prefetch' => wp_dependencies_unique_hosts(),3642		'preconnect'   => array(),3643		'prefetch'     => array(),3644		'prerender'    => array(),3645	);3646 3647	foreach ( $hints as $relation_type => $urls ) {3648		$unique_urls = array();3649 3650		/**3651		 * Filters domains and URLs for resource hints of the given relation type.3652		 *3653		 * @since 4.6.03654		 * @since 4.7.0 The `$urls` parameter accepts arrays of specific HTML attributes3655		 *              as its child elements.3656		 *3657		 * @param array  $urls {3658		 *     Array of resources and their attributes, or URLs to print for resource hints.3659		 *3660		 *     @type array|string ...$0 {3661		 *         Array of resource attributes, or a URL string.3662		 *3663		 *         @type string $href        URL to include in resource hints. Required.3664		 *         @type string $as          How the browser should treat the resource3665		 *                                   (`script`, `style`, `image`, `document`, etc).3666		 *         @type string $crossorigin Indicates the CORS policy of the specified resource.3667		 *         @type float  $pr          Expected probability that the resource hint will be used.3668		 *         @type string $type        Type of the resource (`text/html`, `text/css`, etc).3669		 *     }3670		 * }3671		 * @param string $relation_type The relation type the URLs are printed for. One of3672		 *                              'dns-prefetch', 'preconnect', 'prefetch', or 'prerender'.3673		 */3674		$urls = apply_filters( 'wp_resource_hints', $urls, $relation_type );3675 3676		foreach ( $urls as $key => $url ) {3677			$atts = array();3678 3679			if ( is_array( $url ) ) {3680				if ( isset( $url['href'] ) ) {3681					$atts = $url;3682					$url  = $url['href'];3683				} else {3684					continue;3685				}3686			}3687 3688			$url = esc_url( $url, array( 'http', 'https' ) );3689 3690			if ( ! $url ) {3691				continue;3692			}3693 3694			if ( isset( $unique_urls[ $url ] ) ) {3695				continue;3696			}3697 3698			if ( in_array( $relation_type, array( 'preconnect', 'dns-prefetch' ), true ) ) {3699				$parsed = wp_parse_url( $url );3700 3701				if ( empty( $parsed['host'] ) ) {3702					continue;3703				}3704 3705				if ( 'preconnect' === $relation_type && ! empty( $parsed['scheme'] ) ) {3706					$url = $parsed['scheme'] . '://' . $parsed['host'];3707				} else {3708					// Use protocol-relative URLs for dns-prefetch or if scheme is missing.3709					$url = '//' . $parsed['host'];3710				}3711			}3712 3713			$atts['rel']  = $relation_type;3714			$atts['href'] = $url;3715 3716			$unique_urls[ $url ] = $atts;3717		}3718

History

Introduced in 4.6.0. 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 7.0.4 tag, from src/wp-includes/general-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.