enmi-conf.org: comparison wp/wp-includes/media.php

equal deleted inserted replaced

-:be944660c56a
+:3d72ae0968f4
 	 * @param string|int[] $size  Requested image size. Can be any registered image size name, or
 	 *                            an array of width and height values in pixels (in that order).
 	 */
 	$class = apply_filters( 'get_image_tag_class', $class, $id, $align, $size );
-	$html = '<img src="' . esc_attr( $img_src ) . '" alt="' . esc_attr( $alt ) . '" ' . $title . $hwstring . 'class="' . $class . '" />';
+	$html = '<img src="' . esc_url( $img_src ) . '" alt="' . esc_attr( $alt ) . '" ' . $title . $hwstring . 'class="' . $class . '" />';
 	/**
 	 * Filters the HTML content for the image tag.
 	 *
 	 * @since 2.6.0
 *
 * @since 5.3.0
 * @uses wp_get_additional_image_sizes()
 * @uses get_intermediate_image_sizes()
 *
-* @return array Associative array of the registered image sub-sizes.
+* @return array[] Associative array of arrays of image sub-size information,
+*                 keyed by image size name.
 */
 function wp_get_registered_image_subsizes() {
 	$additional_sizes = wp_get_additional_image_sizes();
 	$all_sizes        = array();
 			'alt'   => trim( strip_tags( get_post_meta( $attachment_id, '_wp_attachment_image_alt', true ) ) ),
 		);
 		// Add `loading` attribute.
 		if ( wp_lazy_loading_enabled( 'img', 'wp_get_attachment_image' ) ) {
-			$default_attr['loading'] = 'lazy';
+			$default_attr['loading'] = wp_get_loading_attr_default( 'wp_get_attachment_image' );
 		}
 		$attr = wp_parse_args( $attr, $default_attr );
 		// If the default value of `lazy` for the `loading` attribute is overridden
 * @return string|false Attachment URL or false if no image is available. If `$size` does not match
 *                      any registered image size, the original image URL will be returned.
 */
 function wp_get_attachment_image_url( $attachment_id, $size = 'thumbnail', $icon = false ) {
 	$image = wp_get_attachment_image_src( $attachment_id, $size, $icon );
-	return isset( $image['0'] ) ? $image['0'] : false;
+	return isset( $image[0] ) ? $image[0] : false;
 }
 /**
 * Get the attachment path relative to the upload directory.
 *
 		 * images to avoid making individual database calls.
 		 */
 		_prime_post_caches( $attachment_ids, false, true );
 	}
-	foreach ( $images as $image => $attachment_id ) {
+	// Iterate through the matches in order of occurrence as it is relevant for whether or not to lazy-load.
-		$filtered_image = $image;
+	foreach ( $matches as $match ) {
+		// Filter an image match.
-		// Add 'width' and 'height' attributes if applicable.
+		if ( isset( $images[ $match[0] ] ) ) {
-		if ( $attachment_id > 0 && false === strpos( $filtered_image, ' width=' ) && false === strpos( $filtered_image, ' height=' ) ) {
+			$filtered_image = $match[0];
-			$filtered_image = wp_img_tag_add_width_and_height_attr( $filtered_image, $context, $attachment_id );
+			$attachment_id  = $images[ $match[0] ];
-		}
+			// Add 'width' and 'height' attributes if applicable.
-		// Add 'srcset' and 'sizes' attributes if applicable.
+			if ( $attachment_id > 0 && false === strpos( $filtered_image, ' width=' ) && false === strpos( $filtered_image, ' height=' ) ) {
-		if ( $attachment_id > 0 && false === strpos( $filtered_image, ' srcset=' ) ) {
+				$filtered_image = wp_img_tag_add_width_and_height_attr( $filtered_image, $context, $attachment_id );
-			$filtered_image = wp_img_tag_add_srcset_and_sizes_attr( $filtered_image, $context, $attachment_id );
+			}
-		}
+			// Add 'srcset' and 'sizes' attributes if applicable.
-		// Add 'loading' attribute if applicable.
+			if ( $attachment_id > 0 && false === strpos( $filtered_image, ' srcset=' ) ) {
-		if ( $add_img_loading_attr && false === strpos( $filtered_image, ' loading=' ) ) {
+				$filtered_image = wp_img_tag_add_srcset_and_sizes_attr( $filtered_image, $context, $attachment_id );
-			$filtered_image = wp_img_tag_add_loading_attr( $filtered_image, $context );
+			}
-		}
+			// Add 'loading' attribute if applicable.
-		if ( $filtered_image !== $image ) {
+			if ( $add_img_loading_attr && false === strpos( $filtered_image, ' loading=' ) ) {
-			$content = str_replace( $image, $filtered_image, $content );
+				$filtered_image = wp_img_tag_add_loading_attr( $filtered_image, $context );
-		}
+			}
-	}
+			/**
-	foreach ( $iframes as $iframe => $attachment_id ) {
+			 * Filters an img tag within the content for a given context.
-		$filtered_iframe = $iframe;
+			 *
+			 * @since 6.0.0
-		// Add 'loading' attribute if applicable.
+			 *
-		if ( $add_iframe_loading_attr && false === strpos( $filtered_iframe, ' loading=' ) ) {
+			 * @param string $filtered_image Full img tag with attributes that will replace the source img tag.
-			$filtered_iframe = wp_iframe_tag_add_loading_attr( $filtered_iframe, $context );
+			 * @param string $context        Additional context, like the current filter name or the function name from where this was called.
-		}
+			 * @param int    $attachment_id  The image attachment ID. May be 0 in case the image is not an attachment.
+			 */
-		if ( $filtered_iframe !== $iframe ) {
+			$filtered_image = apply_filters( 'wp_content_img_tag', $filtered_image, $context, $attachment_id );
-			$content = str_replace( $iframe, $filtered_iframe, $content );
+			if ( $filtered_image !== $match[0] ) {
+				$content = str_replace( $match[0], $filtered_image, $content );
+			}
+			/*
+			 * Unset image lookup to not run the same logic again unnecessarily if the same image tag is used more than
+			 * once in the same blob of content.
+			 */
+			unset( $images[ $match[0] ] );
+		}
+		// Filter an iframe match.
+		if ( isset( $iframes[ $match[0] ] ) ) {
+			$filtered_iframe = $match[0];
+			// Add 'loading' attribute if applicable.
+			if ( $add_iframe_loading_attr && false === strpos( $filtered_iframe, ' loading=' ) ) {
+				$filtered_iframe = wp_iframe_tag_add_loading_attr( $filtered_iframe, $context );
+			}
+			if ( $filtered_iframe !== $match[0] ) {
+				$content = str_replace( $match[0], $filtered_iframe, $content );
+			}
+			/*
+			 * Unset iframe lookup to not run the same logic again unnecessarily if the same iframe tag is used more
+			 * than once in the same blob of content.
+			 */
+			unset( $iframes[ $match[0] ] );
 		}
 	}
 	return $content;
 }
 * @param string $image   The HTML `img` tag where the attribute should be added.
 * @param string $context Additional context to pass to the filters.
 * @return string Converted `img` tag with `loading` attribute added.
 */
 function wp_img_tag_add_loading_attr( $image, $context ) {
+	// Get loading attribute value to use. This must occur before the conditional check below so that even images that
+	// are ineligible for being lazy-loaded are considered.
+	$value = wp_get_loading_attr_default( $context );
 	// Images should have source and dimension attributes for the `loading` attribute to be added.
 	if ( false === strpos( $image, ' src="' ) || false === strpos( $image, ' width="' ) || false === strpos( $image, ' height="' ) ) {
 		return $image;
 	}
 	 * Returning `true` will add the default value.
 	 *
 	 * @since 5.5.0
 	 *
 	 * @param string|bool $value   The `loading` attribute value. Returning a falsey value will result in
-	 *                             the attribute being omitted for the image. Default 'lazy'.
+	 *                             the attribute being omitted for the image.
 	 * @param string      $image   The HTML `img` tag to be filtered.
 	 * @param string      $context Additional context about how the function was called or where the img tag is.
 	 */
-	$value = apply_filters( 'wp_img_tag_add_loading_attr', 'lazy', $image, $context );
+	$value = apply_filters( 'wp_img_tag_add_loading_attr', $value, $image, $context );
 	if ( $value ) {
 		if ( ! in_array( $value, array( 'lazy', 'eager' ), true ) ) {
 			$value = 'lazy';
 		}
 	// visually hidden initially.
 	if ( false !== strpos( $iframe, ' data-secret="' ) ) {
 		return $iframe;
 	}
+	// Get loading attribute value to use. This must occur before the conditional check below so that even iframes that
+	// are ineligible for being lazy-loaded are considered.
+	$value = wp_get_loading_attr_default( $context );
 	// Iframes should have source and dimension attributes for the `loading` attribute to be added.
 	if ( false === strpos( $iframe, ' src="' ) || false === strpos( $iframe, ' width="' ) || false === strpos( $iframe, ' height="' ) ) {
 		return $iframe;
 	}
 	 * Returning `true` will add the default value.
 	 *
 	 * @since 5.7.0
 	 *
 	 * @param string|bool $value   The `loading` attribute value. Returning a falsey value will result in
-	 *                             the attribute being omitted for the iframe. Default 'lazy'.
+	 *                             the attribute being omitted for the iframe.
 	 * @param string      $iframe  The HTML `iframe` tag to be filtered.
 	 * @param string      $context Additional context about how the function was called or where the iframe tag is.
 	 */
-	$value = apply_filters( 'wp_iframe_tag_add_loading_attr', 'lazy', $iframe, $context );
+	$value = apply_filters( 'wp_iframe_tag_add_loading_attr', $value, $iframe, $context );
 	if ( $value ) {
 		if ( ! in_array( $value, array( 'lazy', 'eager' ), true ) ) {
 			$value = 'lazy';
 		}
 * 'width', 'caption', and 'class'.
 *
 * @since 2.6.0
 * @since 3.9.0 The `class` attribute was added.
 * @since 5.1.0 The `caption_id` attribute was added.
+* @since 5.9.0 The `$content` parameter default value changed from `null` to `''`.
 *
 * @param array  $attr {
 *     Attributes of the caption shortcode.
 *
 *     @type string $id         ID of the image and caption container element, i.e. `<figure>` or `<div>`.
 *                              'aligncenter', alignright', 'alignnone'.
 *     @type int    $width      The width of the caption, in pixels.
 *     @type string $caption    The caption text.
 *     @type string $class      Additional class name(s) added to the caption container.
 * }
-* @param string $content Shortcode content.
+* @param string $content Optional. Shortcode content. Default empty string.
 * @return string HTML content to display the caption.
 */
-function img_caption_shortcode( $attr, $content = null ) {
+function img_caption_shortcode( $attr, $content = '' ) {
 	// New-style shortcode with the caption inside the shortcode with the link and image tags.
 	if ( ! isset( $attr['caption'] ) ) {
 		if ( preg_match( '#((?:<a [^>]+>\s*)?<img [^>]+>(?:\s*</a>)?)(.*)#is', $content, $matches ) ) {
 			$content         = $matches[1];
 			$attr['caption'] = trim( $matches[2] );
 	$attached_file = get_attached_file( $attachment->ID );
 	if ( isset( $meta['filesize'] ) ) {
 		$bytes = $meta['filesize'];
 	} elseif ( file_exists( $attached_file ) ) {
-		$bytes = filesize( $attached_file );
+		$bytes = wp_filesize( $attached_file );
 	} else {
 		$bytes = '';
 	}
 	if ( $bytes ) {
 * @global WP_Locale $wp_locale     WordPress date and time locale object.
 *
 * @param array $args {
 *     Arguments for enqueuing media scripts.
 *
-*     @type int|WP_Post A post object or ID.
+*     @type int|WP_Post $post A post object or ID.
 * }
 */
 function wp_enqueue_media( $args = array() ) {
 	// Enqueue me just once per page, please.
 	if ( did_action( 'wp_enqueue_media' ) ) {
 		'returnToLibrary'             => __( '&#8592; Go to library' ),
 		'allMediaItems'               => __( 'All media items' ),
 		'allDates'                    => __( 'All dates' ),
 		'noItemsFound'                => __( 'No items found.' ),
 		'insertIntoPost'              => $post_type_object->labels->insert_into_item,
-		'unattached'                  => __( 'Unattached' ),
+		'unattached'                  => _x( 'Unattached', 'media items' ),
 		'mine'                        => _x( 'Mine', 'media items' ),
 		'trash'                       => _x( 'Trash', 'noun' ),
 		'uploadedToThisPost'          => $post_type_object->labels->uploaded_to_this_item,
 		'warnDelete'                  => __( "You are about to permanently delete this item from your site.\nThis action cannot be undone.\n 'Cancel' to stop, 'OK' to delete." ),
 		'warnBulkDelete'              => __( "You are about to permanently delete these items from your site.\nThis action cannot be undone.\n 'Cancel' to stop, 'OK' to delete." ),
 		'warnBulkTrash'               => __( "You are about to trash these items.\n  'Cancel' to stop, 'OK' to delete." ),
 		'bulkSelect'                  => __( 'Bulk select' ),
 		'trashSelected'               => __( 'Move to Trash' ),
 		'restoreSelected'             => __( 'Restore from Trash' ),
 		'deletePermanently'           => __( 'Delete permanently' ),
+		'errorDeleting'               => __( 'Error in deleting the attachment.' ),
 		'apply'                       => __( 'Apply' ),
 		'filterByDate'                => __( 'Filter by date' ),
 		'filterByType'                => __( 'Filter by type' ),
 		'searchLabel'                 => __( 'Search' ),
 		'searchMediaLabel'            => __( 'Search media' ),          // Backward compatibility pre-5.3.
 	if ( ! $post ) {
 		return array();
 	}
-	if ( ! has_shortcode( $post->post_content, 'gallery' ) ) {
+	if ( ! has_shortcode( $post->post_content, 'gallery' ) && ! has_block( 'gallery', $post->post_content ) ) {
 		return array();
 	}
 	$galleries = array();
 	if ( preg_match_all( '/' . get_shortcode_regex() . '/s', $post->post_content, $matches, PREG_SET_ORDER ) ) {
 							'src' => array_values( array_unique( $srcs ) ),
 						)
 					);
 				}
 			}
+		}
+	}
+	if ( has_block( 'gallery', $post->post_content ) ) {
+		$post_blocks = parse_blocks( $post->post_content );
+		while ( $block = array_shift( $post_blocks ) ) {
+			$has_inner_blocks = ! empty( $block['innerBlocks'] );
+			// Skip blocks with no blockName and no innerHTML.
+			if ( ! $block['blockName'] ) {
+				continue;
+			}
+			// Skip non-Gallery blocks.
+			if ( 'core/gallery' !== $block['blockName'] ) {
+				// Move inner blocks into the root array before skipping.
+				if ( $has_inner_blocks ) {
+					array_push( $post_blocks, ...$block['innerBlocks'] );
+				}
+				continue;
+			}
+			// New Gallery block format as HTML.
+			if ( $has_inner_blocks && $html ) {
+				$block_html  = wp_list_pluck( $block['innerBlocks'], 'innerHTML' );
+				$galleries[] = '<figure>' . implode( ' ', $block_html ) . '</figure>';
+				continue;
+			}
+			$srcs = array();
+			// New Gallery block format as an array.
+			if ( $has_inner_blocks ) {
+				$attrs = wp_list_pluck( $block['innerBlocks'], 'attrs' );
+				$ids   = wp_list_pluck( $attrs, 'id' );
+				foreach ( $ids as $id ) {
+					$url = wp_get_attachment_url( $id );
+					if ( is_string( $url ) && ! in_array( $url, $srcs, true ) ) {
+						$srcs[] = $url;
+					}
+				}
+				$galleries[] = array(
+					'ids' => implode( ',', $ids ),
+					'src' => $srcs,
+				);
+				continue;
+			}
+			// Old Gallery block format as HTML.
+			if ( $html ) {
+				$galleries[] = $block['innerHTML'];
+				continue;
+			}
+			// Old Gallery block format as an array.
+			$ids = ! empty( $block['attrs']['ids'] ) ? $block['attrs']['ids'] : array();
+			// If present, use the image IDs from the JSON blob as canonical.
+			if ( ! empty( $ids ) ) {
+				foreach ( $ids as $id ) {
+					$url = wp_get_attachment_url( $id );
+					if ( is_string( $url ) && ! in_array( $url, $srcs, true ) ) {
+						$srcs[] = $url;
+					}
+				}
+				$galleries[] = array(
+					'ids' => implode( ',', $ids ),
+					'src' => $srcs,
+				);
+				continue;
+			}
+			// Otherwise, extract srcs from the innerHTML.
+			preg_match_all( '#src=([\'"])(.+?)\1#is', $block['innerHTML'], $found_srcs, PREG_SET_ORDER );
+			if ( ! empty( $found_srcs[0] ) ) {
+				foreach ( $found_srcs as $src ) {
+					if ( isset( $src[2] ) && ! in_array( $src[2], $srcs, true ) ) {
+						$srcs[] = $src[2];
+					}
+				}
+			}
+			$galleries[] = array( 'src' => $srcs );
 		}
 	}
 	/**
 	 * Filters the list of all found galleries in the given post.
 		// Mimic the native return format.
 		if ( $width && $height ) {
 			return array(
 				$width,
 				$height,
-				IMAGETYPE_WEBP, // phpcs:ignore PHPCompatibility.Constants.NewConstants.imagetype_webpFound
+				IMAGETYPE_WEBP,
 				sprintf(
 					'width="%d" height="%d"',
 					$width,
 					$height
 				),
 	// The image could not be parsed.
 	return false;
 }
 /**
-* Extracts meta information about a webp file: width, height and type.
+* Extracts meta information about a WebP file: width, height, and type.
 *
 * @since 5.8.0
 *
 * @param string $filename Path to a WebP file.
-* @return array $webp_info {
+* @return array {
 *     An array of WebP image information.
 *
-*     @type array $size {
+*     @type int|false    $width  Image width on success, false on failure.
-*         @type int|false    $width  Image width on success, false on failure.
+*     @type int|false    $height Image height on success, false on failure.
-*         @type int|false    $height Image height on success, false on failure.
+*     @type string|false $type   The WebP type: one of 'lossy', 'lossless' or 'animated-alpha'.
-*         @type string|false $type   The WebP type: one of 'lossy', 'lossless' or 'animated-alpha'.
+*                                False on failure.
-*                                    False on failure.
+* }
-*     }
 */
 function wp_get_webp_info( $filename ) {
 	$width  = false;
 	$height = false;
 	$type   = false;
 	if ( 'image/webp' !== wp_get_image_mime( $filename ) ) {
 		return compact( 'width', 'height', 'type' );
 	}
-	try {
+	$magic = file_get_contents( $filename, false, null, 0, 40 );
-		$handle = fopen( $filename, 'rb' );
-		if ( $handle ) {
+	if ( false === $magic ) {
-			$magic = fread( $handle, 40 );
+		return compact( 'width', 'height', 'type' );
-			fclose( $handle );
+	}
-			// Make sure we got enough bytes.
+	// Make sure we got enough bytes.
-			if ( strlen( $magic ) < 40 ) {
+	if ( strlen( $magic ) < 40 ) {
-				return compact( 'width', 'height', 'type' );
+		return compact( 'width', 'height', 'type' );
-			}
+	}
-			// The headers are a little different for each of the three formats.
+	// The headers are a little different for each of the three formats.
-			// Header values based on WebP docs, see https://developers.google.com/speed/webp/docs/riff_container.
+	// Header values based on WebP docs, see https://developers.google.com/speed/webp/docs/riff_container.
-			switch ( substr( $magic, 12, 4 ) ) {
+	switch ( substr( $magic, 12, 4 ) ) {
-				// Lossy WebP.
+		// Lossy WebP.
-				case 'VP8 ':
+		case 'VP8 ':
-					$parts  = unpack( 'v2', substr( $magic, 26, 4 ) );
+			$parts  = unpack( 'v2', substr( $magic, 26, 4 ) );
-					$width  = (int) ( $parts[1] & 0x3FFF );
+			$width  = (int) ( $parts[1] & 0x3FFF );
-					$height = (int) ( $parts[2] & 0x3FFF );
+			$height = (int) ( $parts[2] & 0x3FFF );
-					$type   = 'lossy';
+			$type   = 'lossy';
-					break;
+			break;
-				// Lossless WebP.
+		// Lossless WebP.
-				case 'VP8L':
+		case 'VP8L':
-					$parts  = unpack( 'C4', substr( $magic, 21, 4 ) );
+			$parts  = unpack( 'C4', substr( $magic, 21, 4 ) );
-					$width  = (int) ( $parts[1] | ( ( $parts[2] & 0x3F ) << 8 ) ) + 1;
+			$width  = (int) ( $parts[1] | ( ( $parts[2] & 0x3F ) << 8 ) ) + 1;
-					$height = (int) ( ( ( $parts[2] & 0xC0 ) >> 6 ) | ( $parts[3] << 2 ) | ( ( $parts[4] & 0x03 ) << 10 ) ) + 1;
+			$height = (int) ( ( ( $parts[2] & 0xC0 ) >> 6 ) | ( $parts[3] << 2 ) | ( ( $parts[4] & 0x03 ) << 10 ) ) + 1;
-					$type   = 'lossless';
+			$type   = 'lossless';
-					break;
+			break;
-				// Animated/alpha WebP.
+		// Animated/alpha WebP.
-				case 'VP8X':
+		case 'VP8X':
-					// Pad 24-bit int.
+			// Pad 24-bit int.
-					$width = unpack( 'V', substr( $magic, 24, 3 ) . "\x00" );
+			$width = unpack( 'V', substr( $magic, 24, 3 ) . "\x00" );
-					$width = (int) ( $width[1] & 0xFFFFFF ) + 1;
+			$width = (int) ( $width[1] & 0xFFFFFF ) + 1;
-					// Pad 24-bit int.
+			// Pad 24-bit int.
-					$height = unpack( 'V', substr( $magic, 27, 3 ) . "\x00" );
+			$height = unpack( 'V', substr( $magic, 27, 3 ) . "\x00" );
-					$height = (int) ( $height[1] & 0xFFFFFF ) + 1;
+			$height = (int) ( $height[1] & 0xFFFFFF ) + 1;
-					$type   = 'animated-alpha';
+			$type   = 'animated-alpha';
-					break;
+			break;
-			}
-		}
-	} catch ( Exception $e ) {
 	}
 	return compact( 'width', 'height', 'type' );
 }
+/**
+* Gets the default value to use for a `loading` attribute on an element.
+*
+* This function should only be called for a tag and context if lazy-loading is generally enabled.
+*
+* The function usually returns 'lazy', but uses certain heuristics to guess whether the current element is likely to
+* appear above the fold, in which case it returns a boolean `false`, which will lead to the `loading` attribute being
+* omitted on the element. The purpose of this refinement is to avoid lazy-loading elements that are within the initial
+* viewport, which can have a negative performance impact.
+*
+* Under the hood, the function uses {@see wp_increase_content_media_count()} every time it is called for an element
+* within the main content. If the element is the very first content element, the `loading` attribute will be omitted.
+* This default threshold of 1 content element to omit the `loading` attribute for can be customized using the
+* {@see 'wp_omit_loading_attr_threshold'} filter.
+*
+* @since 5.9.0
+*
+* @param string $context Context for the element for which the `loading` attribute value is requested.
+* @return string|bool The default `loading` attribute value. Either 'lazy', 'eager', or a boolean `false`, to indicate
+*                     that the `loading` attribute should be skipped.
+*/
+function wp_get_loading_attr_default( $context ) {
+	// Only elements with 'the_content' or 'the_post_thumbnail' context have special handling.
+	if ( 'the_content' !== $context && 'the_post_thumbnail' !== $context ) {
+		return 'lazy';
+	}
+	// Only elements within the main query loop have special handling.
+	if ( is_admin() || ! in_the_loop() || ! is_main_query() ) {
+		return 'lazy';
+	}
+	// Increase the counter since this is a main query content element.
+	$content_media_count = wp_increase_content_media_count();
+	// If the count so far is below the threshold, return `false` so that the `loading` attribute is omitted.
+	if ( $content_media_count <= wp_omit_loading_attr_threshold() ) {
+		return false;
+	}
+	// For elements after the threshold, lazy-load them as usual.
+	return 'lazy';
+}
+/**
+* Gets the threshold for how many of the first content media elements to not lazy-load.
+*
+* This function runs the {@see 'wp_omit_loading_attr_threshold'} filter, which uses a default threshold value of 1.
+* The filter is only run once per page load, unless the `$force` parameter is used.
+*
+* @since 5.9.0
+*
+* @param bool $force Optional. If set to true, the filter will be (re-)applied even if it already has been before.
+*                    Default false.
+* @return int The number of content media elements to not lazy-load.
+*/
+function wp_omit_loading_attr_threshold( $force = false ) {
+	static $omit_threshold;
+	// This function may be called multiple times. Run the filter only once per page load.
+	if ( ! isset( $omit_threshold ) || $force ) {
+		/**
+		 * Filters the threshold for how many of the first content media elements to not lazy-load.
+		 *
+		 * For these first content media elements, the `loading` attribute will be omitted. By default, this is the case
+		 * for only the very first content media element.
+		 *
+		 * @since 5.9.0
+		 *
+		 * @param int $omit_threshold The number of media elements where the `loading` attribute will not be added. Default 1.
+		 */
+		$omit_threshold = apply_filters( 'wp_omit_loading_attr_threshold', 1 );
+	}
+	return $omit_threshold;
+}
+/**
+* Increases an internal content media count variable.
+*
+* @since 5.9.0
+* @access private
+*
+* @param int $amount Optional. Amount to increase by. Default 1.
+* @return int The latest content media count, after the increase.
+*/
+function wp_increase_content_media_count( $amount = 1 ) {
+	static $content_media_count = 0;
+	$content_media_count += $amount;
+	return $content_media_count;
+}

changeset 19	3d72ae0968f4
parent 18	be944660c56a
child 21	48c4eec2b7e6