/**
* Retrieve the URL for an attachment.
*
* @since 2.1.0
*
* @global string $pagenow
*
* @param int $post_id Optional. Attachment ID. Default 0.
* @return string|false Attachment URL, otherwise false.
*/
function wp_get_attachment_url($post_id = 0)
{
$post_id = (int) $post_id;
if (!($post = get_post($post_id))) {
return false;
}
if ('attachment' != $post->post_type) {
return false;
}
$url = '';
// Get attached file.
if ($file = get_post_meta($post->ID, '_wp_attached_file', true)) {
// Get upload directory.
if (($uploads = wp_upload_dir()) && false === $uploads['error']) {
// Check that the upload base exists in the file location.
if (0 === strpos($file, $uploads['basedir'])) {
// Replace file location with url location.
$url = str_replace($uploads['basedir'], $uploads['baseurl'], $file);
} elseif (false !== strpos($file, 'wp-content/uploads')) {
// Get the directory name relative to the basedir (back compat for pre-2.7 uploads)
$url = trailingslashit($uploads['baseurl'] . '/' . _wp_get_attachment_relative_path($file)) . basename($file);
} else {
// It's a newly-uploaded file, therefore $file is relative to the basedir.
$url = $uploads['baseurl'] . "/{$file}";
}
}
}
/*
* If any of the above options failed, Fallback on the GUID as used pre-2.7,
* not recommended to rely upon this.
*/
if (empty($url)) {
$url = get_the_guid($post->ID);
}
// On SSL front-end, URLs should be HTTPS.
if (is_ssl() && !is_admin() && 'wp-login.php' !== $GLOBALS['pagenow']) {
$url = set_url_scheme($url);
}
/**
* Filter the attachment URL.
*
* @since 2.1.0
*
* @param string $url URL for the given attachment.
* @param int $post_id Attachment ID.
*/
$url = apply_filters('wp_get_attachment_url', $url, $post->ID);
if (empty($url)) {
return false;
}
return $url;
}
/**
* A helper function to calculate the image sources to include in a 'srcset' attribute.
*
* @since 4.4.0
*
* @param array $size_array Array of width and height values in pixels (in that order).
* @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 $attachment_id Optional. The image attachment ID to pass to the filter. Default 0.
* @return string|bool The 'srcset' attribute value. False on error or when only one source exists.
*/
function wp_calculate_image_srcset($size_array, $image_src, $image_meta, $attachment_id = 0)
{
/**
* Let plugins pre-filter the image meta to be able to fix inconsistencies in the stored data.
*
* @param array $image_meta The image meta data as returned by 'wp_get_attachment_metadata()'.
* @param array $size_array Array of width and height values in pixels (in that order).
* @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'])) {
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['full'] = array('width' => $image_meta['width'], 'height' => $image_meta['height'], 'file' => $image_basename);
} elseif (strpos($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);
}
$image_baseurl = _wp_upload_dir_baseurl();
$image_baseurl = trailingslashit($image_baseurl) . $dirname;
// Calculate the image aspect ratio.
$image_ratio = $image_height / $image_width;
/*
* 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);
/**
* Filter 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 '1600'.
* @param array $size_array Array of width and height values in pixels (in that order).
*/
$max_srcset_image_width = apply_filters('max_srcset_image_width', 1600, $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 mathces 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 $image) {
// If the file name is part of the `src`, we've confirmed a match.
if (!$src_matched && false !== strpos($image_src, $dirname . $image['file'])) {
$src_matched = true;
}
// Filter out images that are from previous edits.
if ($image_edited && !strpos($image['file'], $image_edit_hash[0])) {
continue;
}
/*
* Filter out images that are wider than '$max_srcset_image_width' unless
* that file is in the 'src' attribute.
*/
if ($max_srcset_image_width && $image['width'] > $max_srcset_image_width && false === strpos($image_src, $image['file'])) {
continue;
}
// Calculate the new image ratio.
if ($image['width']) {
$image_ratio_compare = $image['height'] / $image['width'];
} else {
$image_ratio_compare = 0;
}
// If the new ratio differs by less than 0.002, use it.
if (abs($image_ratio - $image_ratio_compare) < 0.002) {
// Add the URL, descriptor, and value to the sources array to be returned.
$sources[$image['width']] = array('url' => $image_baseurl . $image['file'], 'descriptor' => 'w', 'value' => $image['width']);
}
}
/**
* Filter 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 Array of width and height values in pixels (in that order).
* @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 || count($sources) < 2) {
return false;
}
$srcset = '';
foreach ($sources as $source) {
$srcset .= $source['url'] . ' ' . $source['value'] . $source['descriptor'] . ', ';
}
return rtrim($srcset, ', ');
}
/**
* A helper function to calculate the image sources to include in a 'srcset' attribute.
*
* @since 4.4.0
*
* @param array $size_array Array of width and height values in pixels (in that order).
* @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 $attachment_id Optional. The image attachment ID to pass to the filter. Default 0.
* @return string|bool The 'srcset' attribute value. False on error or when only one source exists.
*/
function wp_calculate_image_srcset($size_array, $image_src, $image_meta, $attachment_id = 0)
{
/**
* Let plugins pre-filter the image meta to be able to fix inconsistencies in the stored data.
*
* @param array $image_meta The image meta data as returned by 'wp_get_attachment_metadata()'.
* @param array $size_array Array of width and height values in pixels (in that order).
* @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' => $image_basename);
} elseif (strpos($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']) . $dirname;
/*
* If currently on HTTPS, prefer HTTPS URLs when we know they're supported by the domain
* (which is to say, when they share the domain name of the current request).
*/
if (is_ssl() && 'https' !== substr($image_baseurl, 0, 5) && parse_url($image_baseurl, PHP_URL_HOST) === $_SERVER['HTTP_HOST']) {
$image_baseurl = set_url_scheme($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 '1600'.
* @param array $size_array Array of width and height values in pixels (in that order).
*/
$max_srcset_image_width = apply_filters('max_srcset_image_width', 1600, $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 (!$src_matched && false !== strpos($image_src, $dirname . $image['file'])) {
$src_matched = $is_src = true;
}
// Filter out images that are from previous edits.
if ($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 Array of width and height values in pixels (in that order).
* @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 || count($sources) < 2) {
return false;
}
$srcset = '';
foreach ($sources as $source) {
$srcset .= str_replace(' ', '%20', $source['url']) . ' ' . $source['value'] . $source['descriptor'] . ', ';
}
return rtrim($srcset, ', ');
}
/**
* Fix sources for large image
*
* @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 Array of width and height values in pixels (in that order).
* @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 $attachment_id Image attachment ID or 0.
*/
public function set_srcset($sources, $size_array, $image_src, $image_meta, $attachment_id)
{
if (!isset($size_array[0]) || 860 !== $size_array[0]) {
return $sources;
}
$image_sizes = $image_meta['sizes'];
$src_matched = 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);
}
$image_baseurl = _wp_upload_dir_baseurl();
$image_baseurl = trailingslashit($image_baseurl) . $dirname;
$image_edited = preg_match('/-e[0-9]{13}/', wp_basename($image_src), $image_edit_hash);
// Get the width and height of the image.
$image_width = (int) $size_array[0];
$image_height = (int) $size_array[1];
// Calculate the image aspect ratio.
$image_ratio = $image_height / $image_width;
/**
* Filter 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 '1600'.
* @param array $size_array Array of width and height values in pixels (in that order).
*/
$max_srcset_image_width = apply_filters('max_srcset_image_width', 1600, $size_array);
foreach ($image_sizes as $image) {
// If the file name is part of the `src`, we've confirmed a match.
if (!$src_matched && false !== strpos($image_src, $dirname . $image['file'])) {
$src_matched = true;
}
// Filter out images that are from previous edits.
if ($image_edited && !strpos($image['file'], $image_edit_hash[0])) {
continue;
}
/*
* Filter out images that are wider than '$max_srcset_image_width' unless
* that file is in the 'src' attribute.
*/
if ($max_srcset_image_width && $image['width'] > $max_srcset_image_width && false === strpos($image_src, $image['file'])) {
continue;
}
// Calculate the new image ratio.
if ($image['width']) {
$image_ratio_compare = $image['height'] / $image['width'];
} else {
$image_ratio_compare = 0;
}
// If the new ratio differs by less than 0.002, use it.
if (abs($image_ratio - $image_ratio_compare) < 0.005) {
// Add the URL, descriptor, and value to the sources array to be returned.
$sources[$image['width']] = array('url' => $image_baseurl . $image['file'], 'descriptor' => 'w', 'value' => $image['width']);
}
}
return $sources;
}
