/**
* Retrieves the value for an image attachment's 'srcset' attribute.
*
* @since 4.4.0
*
* @param int $attachment_id Image attachment ID.
* @param array|string $size Image size. Accepts any valid image size, or an array of width and height
* values in pixels (in that order). Default 'medium'.
* @return string|bool A 'srcset' value string or false.
*/
function wp_get_attachment_image_srcset($attachment_id, $size = 'medium')
{
$srcset_array = wp_get_attachment_image_srcset_array($attachment_id, $size);
// Only return a srcset value if there is more than one source.
if (count($srcset_array) <= 1) {
return false;
}
$srcset = '';
foreach ($srcset_array as $source) {
$srcset .= $source['url'] . ' ' . $source['value'] . $source['descriptor'] . ', ';
}
/**
* Filter the output of wp_get_attachment_image_srcset().
*
* @since 4.4.0
*
* @param string $srcset A source set formated for a `srcset` attribute.
* @param int $attachment_id Attachment ID for image.
* @param array|string $size Image size. Accepts any valid image size, or an array of width and height
* values in pixels (in that order). Default 'medium'.
*/
return apply_filters('wp_get_attachment_image_srcset', rtrim($srcset, ', '), $attachment_id, $size);
}
/**
* Retrieves the value for an image attachment's 'srcset' attribute.
*
* @since 4.4.0
*
* @param int $attachment_id Image attachment ID.
* @param string $size Optional. Name of image size. Default 'medium'.
* @return string|bool A 'srcset' value string or false.
*/
function wp_get_attachment_image_srcset($attachment_id, $size = 'medium')
{
$srcset_array = wp_get_attachment_image_srcset_array($attachment_id, $size);
// Only return a srcset value if there is more than one source.
if (count($srcset_array) <= 1) {
return false;
}
$srcset = '';
foreach ($srcset_array as $source) {
$srcset .= $source['url'] . ' ' . $source['value'] . $source['descriptor'] . ', ';
}
/**
* Filter the output of wp_get_attachment_image_srcset().
*
* @since 4.4.0
*
* @param string $srcset A source set formated for a `srcset` attribute.
* @param int $attachment_id Attachment ID for image.
* @param array|string $size Size of image, either array or string.
*/
return apply_filters('wp_get_attachment_image_srcset', rtrim($srcset, ', '), $attachment_id, $size);
}
/**
* @ticket 33641
*/
function test_wp_get_attachment_image_srcset_array_no_width()
{
// Filter image_downsize() output.
add_filter('wp_generate_attachment_metadata', array($this, '_test_wp_get_attachment_image_srcset_array_no_width_filter'));
$old_meta = get_post_meta(self::$large_id, '_wp_attachment_metadata', true);
$file = get_attached_file(self::$large_id);
$data = wp_generate_attachment_metadata(self::$large_id, $file);
wp_update_attachment_metadata(self::$large_id, $data);
$srcset = wp_get_attachment_image_srcset_array(self::$large_id, 'medium');
update_post_meta(self::$large_id, '_wp_attachment_metadata', $old_meta);
// The srcset should be false.
$this->assertFalse($srcset);
}
