wp_calculate_image_srcset() │ WP 4.4.0
A helper function to calculate the image sources to include in a 'srcset' attribute.
Возвращает
Строку|false
. The 'srcset' attribute value. False on error or when only one source exists.
Использование
wp_calculate_image_srcset( $size_array, $image_src, $image_meta, $attachment_id );
- $size_array(int[]) (обязательный)
An array of width and height values.
-
0(int)
The width in pixels. - 1(int)
The height in pixels.
-
- $image_src(строка) (обязательный)
- The 'src' of the image.
- $image_meta(массив) (обязательный)
- The image meta data as returned by wp_get_attachment_metadata().
- $attachment_id(int)
- The image attachment ID.
Список изменений
С версии 4.4.0 | Введена. |
Код wp_calculate_image_srcset() wp calculate image srcset WP 6.7.1
function wp_calculate_image_srcset( $size_array, $image_src, $image_meta, $attachment_id = 0 ) { /** * Pre-filters the image meta to be able to fix inconsistencies in the stored data. * * @since 4.5.0 * * @param array $image_meta The image meta data as returned by 'wp_get_attachment_metadata()'. * @param int[] $size_array { * An array of requested width and height values. * * @type int $0 The width in pixels. * @type int $1 The height in pixels. * } * @param string $image_src The 'src' of the image. * @param int $attachment_id The image attachment ID or 0 if not supplied. */ $image_meta = apply_filters( 'wp_calculate_image_srcset_meta', $image_meta, $size_array, $image_src, $attachment_id ); if ( empty( $image_meta['sizes'] ) || ! isset( $image_meta['file'] ) || strlen( $image_meta['file'] ) < 4 ) { return false; } $image_sizes = $image_meta['sizes']; // Get the width and height of the image. $image_width = (int) $size_array[0]; $image_height = (int) $size_array[1]; // Bail early if error/no width. if ( $image_width < 1 ) { return false; } $image_basename = wp_basename( $image_meta['file'] ); /* * WordPress flattens animated GIFs into one frame when generating intermediate sizes. * To avoid hiding animation in user content, if src is a full size GIF, a srcset attribute is not generated. * If src is an intermediate size GIF, the full size is excluded from srcset to keep a flattened GIF from becoming animated. */ if ( ! isset( $image_sizes['thumbnail']['mime-type'] ) || 'image/gif' !== $image_sizes['thumbnail']['mime-type'] ) { $image_sizes[] = array( 'width' => $image_meta['width'], 'height' => $image_meta['height'], 'file' => $image_basename, ); } elseif ( str_contains( $image_src, $image_meta['file'] ) ) { return false; } // Retrieve the uploads sub-directory from the full size image. $dirname = _wp_get_attachment_relative_path( $image_meta['file'] ); if ( $dirname ) { $dirname = trailingslashit( $dirname ); } $upload_dir = wp_get_upload_dir(); $image_baseurl = trailingslashit( $upload_dir['baseurl'] ) . $dirname; /* * If currently on HTTPS, prefer HTTPS URLs when we know they're supported by the domain * (which is to say, when they share the domain name of the current request). */ if ( is_ssl() && ! str_starts_with( $image_baseurl, 'https' ) ) { /* * Since the `Host:` header might contain a port, it should * be compared against the image URL using the same port. */ $parsed = parse_url( $image_baseurl ); $domain = isset( $parsed['host'] ) ? $parsed['host'] : ''; if ( isset( $parsed['port'] ) ) { $domain .= ':' . $parsed['port']; } if ( $_SERVER['HTTP_HOST'] === $domain ) { $image_baseurl = set_url_scheme( $image_baseurl, 'https' ); } } /* * Images that have been edited in WordPress after being uploaded will * contain a unique hash. Look for that hash and use it later to filter * out images that are leftovers from previous versions. */ $image_edited = preg_match( '/-e[0-9]{13}/', wp_basename( $image_src ), $image_edit_hash ); /** * Filters the maximum image width to be included in a 'srcset' attribute. * * @since 4.4.0 * * @param int $max_width The maximum image width to be included in the 'srcset'. Default '2048'. * @param int[] $size_array { * An array of requested width and height values. * * @type int $0 The width in pixels. * @type int $1 The height in pixels. * } */ $max_srcset_image_width = apply_filters( 'max_srcset_image_width', 2048, $size_array ); // Array to hold URL candidates. $sources = array(); /** * To make sure the ID matches our image src, we will check to see if any sizes in our attachment * meta match our $image_src. If no matches are found we don't return a srcset to avoid serving * an incorrect image. See #35045. */ $src_matched = false; /* * Loop through available images. Only use images that are resized * versions of the same edit. */ foreach ( $image_sizes as $image ) { $is_src = false; // Check if image meta isn't corrupted. if ( ! is_array( $image ) ) { continue; } // If the file name is part of the `src`, we've confirmed a match. if ( ! $src_matched && str_contains( $image_src, $dirname . $image['file'] ) ) { $src_matched = true; $is_src = true; } // Filter out images that are from previous edits. if ( $image_edited && ! strpos( $image['file'], $image_edit_hash[0] ) ) { continue; } /* * Filters out images that are wider than '$max_srcset_image_width' unless * that file is in the 'src' attribute. */ if ( $max_srcset_image_width && $image['width'] > $max_srcset_image_width && ! $is_src ) { continue; } // If the image dimensions are within 1px of the expected size, use it. if ( wp_image_matches_ratio( $image_width, $image_height, $image['width'], $image['height'] ) ) { // Add the URL, descriptor, and value to the sources array to be returned. $source = array( 'url' => $image_baseurl . $image['file'], 'descriptor' => 'w', 'value' => $image['width'], ); // The 'src' image has to be the first in the 'srcset', because of a bug in iOS8. See #35030. if ( $is_src ) { $sources = array( $image['width'] => $source ) + $sources; } else { $sources[ $image['width'] ] = $source; } } } /** * Filters an image's 'srcset' sources. * * @since 4.4.0 * * @param array $sources { * One or more arrays of source data to include in the 'srcset'. * * @type array $width { * @type string $url The URL of an image source. * @type string $descriptor The descriptor type used in the image candidate string, * either 'w' or 'x'. * @type int $value The source width if paired with a 'w' descriptor, or a * pixel density value if paired with an 'x' descriptor. * } * } * @param array $size_array { * An array of requested width and height values. * * @type int $0 The width in pixels. * @type int $1 The height in pixels. * } * @param string $image_src The 'src' of the image. * @param array $image_meta The image meta data as returned by 'wp_get_attachment_metadata()'. * @param int $attachment_id Image attachment ID or 0. */ $sources = apply_filters( 'wp_calculate_image_srcset', $sources, $size_array, $image_src, $image_meta, $attachment_id ); // Only return a 'srcset' value if there is more than one source. if ( ! $src_matched || ! is_array( $sources ) || count( $sources ) < 2 ) { return false; } $srcset = ''; foreach ( $sources as $source ) { $srcset .= str_replace( ' ', '%20', $source['url'] ) . ' ' . $source['value'] . $source['descriptor'] . ', '; } return rtrim( $srcset, ', ' ); }