Changeset 56612 for trunk/src/wp-includes/media.php

Timestamp:

09/18/2023 02:53:37 PM (22 months ago)

Author:

flixos90

Message:

Media: Enhance wp_get_loading_optimization_attributes() to support arbitrary context values.

The wp_get_loading_optimization_attributes() function, which was introduced in 6.3, based on the now deprecated wp_get_loading_attr_default() function introduced in 5.5, relies on a $context parameter based on which it may alter its behavior and the attributes returned. So far, it has only supported context values used within WordPress core.

This changeset decouples the behaviors of the function from specific contexts, allowing for more flexibility. Theme and plugin developers will be able to rely on their own context values when rendering images in non-standard ways, rather than being forced to use a core context, to get the loading optimization benefits the function provides.

As part of this change, a wp_loading_optimization_force_header_contexts filter is introduced, which allows filtering the map of context values and whether they should be considered header contexts, i.e. i.e. any image having one of these contexts will be assumed to appear above the fold.

Props mukesh27, costdev, flixos90.
Fixes #58894.

File:

• trunk/src/wp-includes/media.php (modified) (2 diffs)

trunk/src/wp-includes/media.php

@@ -5653 +5653 @@
      * high priority.
      */
-    switch ( $context ) {
-        case 'the_post_thumbnail':
-        case 'wp_get_attachment_image':
-        case 'widget_media_image':
-            if ( doing_filter( 'the_content' ) ) {
-                return $loading_attrs;
-            }
+    // TODO: Handle shortcode images together with the content (see https://core.trac.wordpress.org/ticket/58853).
+    if ( 'the_content' !== $context && 'do_shortcode' !== $context && doing_filter( 'the_content' ) ) {
+        return $loading_attrs;
     }
 
@@ -5710 +5706 @@
 
     if ( null === $maybe_in_viewport ) {
-        switch ( $context ) {
-            // Consider elements with these header-specific contexts to be in viewport.
-            case 'template_part_' . WP_TEMPLATE_PART_AREA_HEADER:
-            case 'get_header_image_tag':
-                $maybe_in_viewport    = true;
-                $maybe_increase_count = true;
-                break;
-            // Count main content elements and detect whether in viewport.
-            case 'the_content':
-            case 'the_post_thumbnail':
-            case 'do_shortcode':
-                // Only elements within the main query loop have special handling.
-                if ( ! is_admin() && in_the_loop() && is_main_query() ) {
-                    /*
-                     * Get the content media count, since this is a main query
-                     * content element. This is accomplished by "increasing"
-                     * the count by zero, as the only way to get the count is
-                     * to call this function.
-                     * The actual count increase happens further below, based
-                     * on the `$increase_count` flag set here.
-                     */
-                    $content_media_count = wp_increase_content_media_count( 0 );
-                    $increase_count      = true;
-
-                    // If the count so far is below the threshold, `loading` attribute is omitted.
-                    if ( $content_media_count < wp_omit_loading_attr_threshold() ) {
-                        $maybe_in_viewport = true;
-                    } else {
-                        $maybe_in_viewport = false;
-                    }
-                }
-                /*
-                 * For the 'the_post_thumbnail' context, the following case
-                 * clause needs to be considered as well, therefore skip the
-                 * break statement here if the viewport has not been
-                 * determined.
-                 */
-                if ( 'the_post_thumbnail' !== $context || null !== $maybe_in_viewport ) {
-                    break;
-                }
-            // phpcs:ignore Generic.WhiteSpace.ScopeIndent.Incorrect
-            // Consider elements before the loop as being in viewport.
-            case 'wp_get_attachment_image':
-            case 'widget_media_image':
-                if (
-                    // Only apply for main query but before the loop.
-                    $wp_query->before_loop && $wp_query->is_main_query()
-                    /*
-                     * Any image before the loop, but after the header has started should not be lazy-loaded,
-                     * except when the footer has already started which can happen when the current template
-                     * does not include any loop.
-                     */
-                    && did_action( 'get_header' ) && ! did_action( 'get_footer' )
-                ) {
-                    $maybe_in_viewport    = true;
-                    $maybe_increase_count = true;
-                }
-                break;
+        $header_enforced_contexts = array(
+            'template_part_' . WP_TEMPLATE_PART_AREA_HEADER => true,
+            'get_header_image_tag'                          => true,
+        );
+
+        /**
+         * Filters the header-specific contexts.
+         *
+         * @since 6.4.0
+         *
+         * @param array $default_header_enforced_contexts Map of contexts for which elements should be considered
+         *                                                in the header of the page, as $context => $enabled
+         *                                                pairs. The $enabled should always be true.
+         */
+        $header_enforced_contexts = apply_filters( 'wp_loading_optimization_force_header_contexts', $header_enforced_contexts );
+
+        // Consider elements with these header-specific contexts to be in viewport.
+        if ( isset( $header_enforced_contexts[ $context ] ) ) {
+            $maybe_in_viewport    = true;
+            $maybe_increase_count = true;
+        } elseif ( ! is_admin() && in_the_loop() && is_main_query() ) {
+            /*
+             * Get the content media count, since this is a main query
+             * content element. This is accomplished by "increasing"
+             * the count by zero, as the only way to get the count is
+             * to call this function.
+             * The actual count increase happens further below, based
+             * on the `$increase_count` flag set here.
+             */
+            $content_media_count = wp_increase_content_media_count( 0 );
+            $increase_count      = true;
+
+            // If the count so far is below the threshold, `loading` attribute is omitted.
+            if ( $content_media_count < wp_omit_loading_attr_threshold() ) {
+                $maybe_in_viewport = true;
+            } else {
+                $maybe_in_viewport = false;
+            }
+        } elseif (
+            // Only apply for main query but before the loop.
+            $wp_query->before_loop && $wp_query->is_main_query()
+            /*
+             * Any image before the loop, but after the header has started should not be lazy-loaded,
+             * except when the footer has already started which can happen when the current template
+             * does not include any loop.
+             */
+            && did_action( 'get_header' ) && ! did_action( 'get_footer' )
+            ) {
+            $maybe_in_viewport    = true;
+            $maybe_increase_count = true;
         }
     }