0 ) {
$max_width = min( intval( $content_width ), $max_width );
}
} elseif ( $size === 'large' ) {
/*
* We're inserting a large size image into the editor. If it's a really
* big image we'll scale it down to fit reasonably within the editor
* itself, and within the theme's content width if it's known. The user
* can resize it in the editor if they wish.
*/
$max_width = intval( get_option( 'large_size_w' ) );
$max_height = intval( get_option( 'large_size_h' ) );
if ( intval( $content_width ) > 0 ) {
$max_width = min( intval( $content_width ), $max_width );
}
} elseif ( ! empty( $_wp_additional_image_sizes ) && in_array( $size, array_keys( $_wp_additional_image_sizes ), true ) ) {
$max_width = intval( $_wp_additional_image_sizes[ $size ]['width'] );
$max_height = intval( $_wp_additional_image_sizes[ $size ]['height'] );
// Only in admin. Assume that theme authors know what they're doing.
if ( intval( $content_width ) > 0 && 'edit' === $context ) {
$max_width = min( intval( $content_width ), $max_width );
}
} else { // $size == 'full' has no constraint
$max_width = $width;
$max_height = $height;
}
/**
* Filters the maximum image size dimensions for the editor.
*
* @since 2.5.0
*
* @param array $max_image_size An array with the width as the first element,
* and the height as the second element.
* @param string|array $size Size of what the result image should be.
* @param string $context The context the image is being resized for.
* Possible values are 'display' (like in a theme)
* or 'edit' (like inserting into an editor).
*/
list( $max_width, $max_height ) = apply_filters( 'editor_max_image_size', array( $max_width, $max_height ), $size, $context );
return wp_constrain_dimensions( $width, $height, $max_width, $max_height );
}
/**
* Retrieve width and height attributes using given width and height values.
*
* Both attributes are required in the sense that both parameters must have a
* value, but are optional in that if you set them to false or null, then they
* will not be added to the returned string.
*
* You can set the value using a string, but it will only take numeric values.
* If you wish to put 'px' after the numbers, then it will be stripped out of
* the return.
*
* @since 2.5.0
*
* @param int|string $width Image width in pixels.
* @param int|string $height Image height in pixels.
* @return string HTML attributes for width and, or height.
*/
function image_hwstring( $width, $height ) {
$out = '';
if ( $width ) {
$out .= 'width="' . intval( $width ) . '" ';
}
if ( $height ) {
$out .= 'height="' . intval( $height ) . '" ';
}
return $out;
}
/**
* Scale an image to fit a particular size (such as 'thumb' or 'medium').
*
* Array with image url, width, height, and whether is intermediate size, in
* that order is returned on success is returned. $is_intermediate is true if
* $url is a resized image, false if it is the original.
*
* The URL might be the original image, or it might be a resized version. This
* function won't create a new resized copy, it will just return an already
* resized one if it exists.
*
* A plugin may use the {@see 'image_downsize'} filter to hook into and offer image
* resizing services for images. The hook must return an array with the same
* elements that are returned in the function. The first element being the URL
* to the new image that was resized.
*
* @since 2.5.0
*
* @param int $id Attachment ID for image.
* @param array|string $size Optional. Image size to scale to. Accepts any valid image size,
* or an array of width and height values in pixels (in that order).
* Default 'medium'.
* @return false|array Array containing the image URL, width, height, and boolean for whether
* the image is an intermediate size. False on failure.
*/
function image_downsize( $id, $size = 'medium' ) {
$is_image = wp_attachment_is_image( $id );
/**
* Filters whether to preempt the output of image_downsize().
*
* Passing a truthy value to the filter will effectively short-circuit
* down-sizing the image, returning that value as output instead.
*
* @since 2.5.0
*
* @param bool $downsize Whether to short-circuit the image downsize. Default false.
* @param int $id Attachment ID for image.
* @param array|string $size Size of image. Image size or array of width and height values (in that order).
* Default 'medium'.
*/
$out = apply_filters( 'image_downsize', false, $id, $size );
if ( $out ) {
return $out;
}
$img_url = wp_get_attachment_url( $id );
$meta = wp_get_attachment_metadata( $id );
$width = 0;
$height = 0;
$is_intermediate = false;
$img_url_basename = wp_basename( $img_url );
// If the file isn't an image, attempt to replace its URL with a rendered image from its meta.
// Otherwise, a non-image type could be returned.
if ( ! $is_image ) {
if ( ! empty( $meta['sizes'] ) ) {
$img_url = str_replace( $img_url_basename, $meta['sizes']['full']['file'], $img_url );
$img_url_basename = $meta['sizes']['full']['file'];
$width = $meta['sizes']['full']['width'];
$height = $meta['sizes']['full']['height'];
} else {
return false;
}
}
// try for a new style intermediate size
$intermediate = image_get_intermediate_size( $id, $size );
if ( $intermediate ) {
$img_url = str_replace( $img_url_basename, $intermediate['file'], $img_url );
$width = $intermediate['width'];
$height = $intermediate['height'];
$is_intermediate = true;
} elseif ( $size === 'thumbnail' ) {
// fall back to the old thumbnail
$thumb_file = wp_get_attachment_thumb_file( $id );
$info = null;
if ( $thumb_file ) {
$info = getimagesize( $thumb_file );
}
if ( $thumb_file && $info ) {
$img_url = str_replace( $img_url_basename, wp_basename( $thumb_file ), $img_url );
$width = $info[0];
$height = $info[1];
$is_intermediate = true;
}
}
if ( ! $width && ! $height && isset( $meta['width'], $meta['height'] ) ) {
// any other type: use the real image
$width = $meta['width'];
$height = $meta['height'];
}
if ( $img_url ) {
// we have the actual image size, but might need to further constrain it if content_width is narrower
list( $width, $height ) = image_constrain_size_for_editor( $width, $height, $size );
return array( $img_url, $width, $height, $is_intermediate );
}
return false;
}
/**
* Register a new image size.
*
* Cropping behavior for the image size is dependent on the value of $crop:
* 1. If false (default), images will be scaled, not cropped.
* 2. If an array in the form of array( x_crop_position, y_crop_position ):
* - x_crop_position accepts 'left' 'center', or 'right'.
* - y_crop_position accepts 'top', 'center', or 'bottom'.
* Images will be cropped to the specified dimensions within the defined crop area.
* 3. If true, images will be cropped to the specified dimensions using center positions.
*
* @since 2.9.0
*
* @global array $_wp_additional_image_sizes Associative array of additional image sizes.
*
* @param string $name Image size identifier.
* @param int $width Optional. Image width in pixels. Default 0.
* @param int $height Optional. Image height in pixels. Default 0.
* @param bool|array $crop Optional. Whether to crop images to specified width and height or resize.
* An array can specify positioning of the crop area. Default false.
*/
function add_image_size( $name, $width = 0, $height = 0, $crop = false ) {
global $_wp_additional_image_sizes;
$_wp_additional_image_sizes[ $name ] = array(
'width' => absint( $width ),
'height' => absint( $height ),
'crop' => $crop,
);
}
/**
* Check if an image size exists.
*
* @since 3.9.0
*
* @param string $name The image size to check.
* @return bool True if the image size exists, false if not.
*/
function has_image_size( $name ) {
$sizes = wp_get_additional_image_sizes();
return isset( $sizes[ $name ] );
}
/**
* Remove a new image size.
*
* @since 3.9.0
*
* @global array $_wp_additional_image_sizes
*
* @param string $name The image size to remove.
* @return bool True if the image size was successfully removed, false on failure.
*/
function remove_image_size( $name ) {
global $_wp_additional_image_sizes;
if ( isset( $_wp_additional_image_sizes[ $name ] ) ) {
unset( $_wp_additional_image_sizes[ $name ] );
return true;
}
return false;
}
/**
* Registers an image size for the post thumbnail.
*
* @since 2.9.0
*
* @see add_image_size() for details on cropping behavior.
*
* @param int $width Image width in pixels.
* @param int $height Image height in pixels.
* @param bool|array $crop Optional. Whether to crop images to specified width and height or resize.
* An array can specify positioning of the crop area. Default false.
*/
function set_post_thumbnail_size( $width = 0, $height = 0, $crop = false ) {
add_image_size( 'post-thumbnail', $width, $height, $crop );
}
/**
* Gets an img tag for an image attachment, scaling it down if requested.
*
* The {@see 'get_image_tag_class'} filter allows for changing the class name for the
* image without having to use regular expressions on the HTML content. The
* parameters are: what WordPress will use for the class, the Attachment ID,
* image align value, and the size the image should be.
*
* The second filter, {@see 'get_image_tag'}, has the HTML content, which can then be
* further manipulated by a plugin to change all attribute values and even HTML
* content.
*
* @since 2.5.0
*
* @param int $id Attachment ID.
* @param string $alt Image Description for the alt attribute.
* @param string $title Image Description for the title attribute.
* @param string $align Part of the class name for aligning the image.
* @param string|array $size Optional. Registered image size to retrieve a tag for. Accepts any
* valid image size, or an array of width and height values in pixels
* (in that order). Default 'medium'.
* @return string HTML IMG element for given image attachment
*/
function get_image_tag( $id, $alt, $title, $align, $size = 'medium' ) {
list( $img_src, $width, $height ) = image_downsize( $id, $size );
$hwstring = image_hwstring( $width, $height );
$title = $title ? 'title="' . esc_attr( $title ) . '" ' : '';
$class = 'align' . esc_attr( $align ) . ' size-' . esc_attr( $size ) . ' wp-image-' . $id;
/**
* Filters the value of the attachment's image tag class attribute.
*
* @since 2.6.0
*
* @param string $class CSS class name or space-separated list of classes.
* @param int $id Attachment ID.
* @param string $align Part of the class name for aligning the image.
* @param string|array $size Size of image. Image size or array of width and height values (in that order).
* Default 'medium'.
*/
$class = apply_filters( 'get_image_tag_class', $class, $id, $align, $size );
$html = '';
/**
* Filters the HTML content for the image tag.
*
* @since 2.6.0
*
* @param string $html HTML content for the image.
* @param int $id Attachment ID.
* @param string $alt Alternate text.
* @param string $title Attachment title.
* @param string $align Part of the class name for aligning the image.
* @param string|array $size Size of image. Image size or array of width and height values (in that order).
* Default 'medium'.
*/
return apply_filters( 'get_image_tag', $html, $id, $alt, $title, $align, $size );
}
/**
* Calculates the new dimensions for a down-sampled image.
*
* If either width or height are empty, no constraint is applied on
* that dimension.
*
* @since 2.5.0
*
* @param int $current_width Current width of the image.
* @param int $current_height Current height of the image.
* @param int $max_width Optional. Max width in pixels to constrain to. Default 0.
* @param int $max_height Optional. Max height in pixels to constrain to. Default 0.
* @return array First item is the width, the second item is the height.
*/
function wp_constrain_dimensions( $current_width, $current_height, $max_width = 0, $max_height = 0 ) {
if ( ! $max_width && ! $max_height ) {
return array( $current_width, $current_height );
}
$width_ratio = 1.0;
$height_ratio = 1.0;
$did_width = false;
$did_height = false;
if ( $max_width > 0 && $current_width > 0 && $current_width > $max_width ) {
$width_ratio = $max_width / $current_width;
$did_width = true;
}
if ( $max_height > 0 && $current_height > 0 && $current_height > $max_height ) {
$height_ratio = $max_height / $current_height;
$did_height = true;
}
// Calculate the larger/smaller ratios
$smaller_ratio = min( $width_ratio, $height_ratio );
$larger_ratio = max( $width_ratio, $height_ratio );
if ( (int) round( $current_width * $larger_ratio ) > $max_width || (int) round( $current_height * $larger_ratio ) > $max_height ) {
// The larger ratio is too big. It would result in an overflow.
$ratio = $smaller_ratio;
} else {
// The larger ratio fits, and is likely to be a more "snug" fit.
$ratio = $larger_ratio;
}
// Very small dimensions may result in 0, 1 should be the minimum.
$w = max( 1, (int) round( $current_width * $ratio ) );
$h = max( 1, (int) round( $current_height * $ratio ) );
// Sometimes, due to rounding, we'll end up with a result like this: 465x700 in a 177x177 box is 117x176... a pixel short
// We also have issues with recursive calls resulting in an ever-changing result. Constraining to the result of a constraint should yield the original result.
// Thus we look for dimensions that are one pixel shy of the max value and bump them up
// Note: $did_width means it is possible $smaller_ratio == $width_ratio.
if ( $did_width && $w === $max_width - 1 ) {
$w = $max_width; // Round it up
}
// Note: $did_height means it is possible $smaller_ratio == $height_ratio.
if ( $did_height && $h === $max_height - 1 ) {
$h = $max_height; // Round it up
}
/**
* Filters dimensions to constrain down-sampled images to.
*
* @since 4.1.0
*
* @param array $dimensions The image width and height.
* @param int $current_width The current width of the image.
* @param int $current_height The current height of the image.
* @param int $max_width The maximum width permitted.
* @param int $max_height The maximum height permitted.
*/
return apply_filters( 'wp_constrain_dimensions', array( $w, $h ), $current_width, $current_height, $max_width, $max_height );
}
/**
* Retrieves calculated resize dimensions for use in WP_Image_Editor.
*
* Calculates dimensions and coordinates for a resized image that fits
* within a specified width and height.
*
* Cropping behavior is dependent on the value of $crop:
* 1. If false (default), images will not be cropped.
* 2. If an array in the form of array( x_crop_position, y_crop_position ):
* - x_crop_position accepts 'left' 'center', or 'right'.
* - y_crop_position accepts 'top', 'center', or 'bottom'.
* Images will be cropped to the specified dimensions within the defined crop area.
* 3. If true, images will be cropped to the specified dimensions using center positions.
*
* @since 2.5.0
*
* @param int $orig_w Original width in pixels.
* @param int $orig_h Original height in pixels.
* @param int $dest_w New width in pixels.
* @param int $dest_h New height in pixels.
* @param bool|array $crop Optional. Whether to crop image to specified width and height or resize.
* An array can specify positioning of the crop area. Default false.
* @return false|array False on failure. Returned array matches parameters for `imagecopyresampled()`.
*/
function image_resize_dimensions( $orig_w, $orig_h, $dest_w, $dest_h, $crop = false ) {
if ( $orig_w <= 0 || $orig_h <= 0 ) {
return false;
}
// at least one of dest_w or dest_h must be specific
if ( $dest_w <= 0 && $dest_h <= 0 ) {
return false;
}
/**
* Filters whether to preempt calculating the image resize dimensions.
*
* Passing a non-null value to the filter will effectively short-circuit
* image_resize_dimensions(), returning that value instead.
*
* @since 3.4.0
*
* @param null|mixed $null Whether to preempt output of the resize dimensions.
* @param int $orig_w Original width in pixels.
* @param int $orig_h Original height in pixels.
* @param int $dest_w New width in pixels.
* @param int $dest_h New height in pixels.
* @param bool|array $crop Whether to crop image to specified width and height or resize.
* An array can specify positioning of the crop area. Default false.
*/
$output = apply_filters( 'image_resize_dimensions', null, $orig_w, $orig_h, $dest_w, $dest_h, $crop );
if ( null !== $output ) {
return $output;
}
if ( $crop ) {
// crop the largest possible portion of the original image that we can size to $dest_w x $dest_h
$aspect_ratio = $orig_w / $orig_h;
$new_w = min( $dest_w, $orig_w );
$new_h = min( $dest_h, $orig_h );
if ( ! $new_w ) {
$new_w = (int) round( $new_h * $aspect_ratio );
}
if ( ! $new_h ) {
$new_h = (int) round( $new_w / $aspect_ratio );
}
$size_ratio = max( $new_w / $orig_w, $new_h / $orig_h );
$crop_w = round( $new_w / $size_ratio );
$crop_h = round( $new_h / $size_ratio );
if ( ! is_array( $crop ) || count( $crop ) !== 2 ) {
$crop = array( 'center', 'center' );
}
list( $x, $y ) = $crop;
if ( 'left' === $x ) {
$s_x = 0;
} elseif ( 'right' === $x ) {
$s_x = $orig_w - $crop_w;
} else {
$s_x = floor( ( $orig_w - $crop_w ) / 2 );
}
if ( 'top' === $y ) {
$s_y = 0;
} elseif ( 'bottom' === $y ) {
$s_y = $orig_h - $crop_h;
} else {
$s_y = floor( ( $orig_h - $crop_h ) / 2 );
}
} else {
// don't crop, just resize using $dest_w x $dest_h as a maximum bounding box
$crop_w = $orig_w;
$crop_h = $orig_h;
$s_x = 0;
$s_y = 0;
list( $new_w, $new_h ) = wp_constrain_dimensions( $orig_w, $orig_h, $dest_w, $dest_h );
}
// if the resulting image would be the same size or larger we don't want to resize it
if ( $new_w >= $orig_w && $new_h >= $orig_h && intval( $dest_w ) !== intval( $orig_w ) && intval( $dest_h ) !== intval( $orig_h ) ) {
return false;
}
// the return array matches the parameters to imagecopyresampled()
// int dst_x, int dst_y, int src_x, int src_y, int dst_w, int dst_h, int src_w, int src_h
return array( 0, 0, (int) $s_x, (int) $s_y, (int) $new_w, (int) $new_h, (int) $crop_w, (int) $crop_h );
}
/**
* Resizes an image to make a thumbnail or intermediate size.
*
* The returned array has the file size, the image width, and image height. The
* {@see 'image_make_intermediate_size'} filter can be used to hook in and change the
* values of the returned array. The only parameter is the resized file path.
*
* @since 2.5.0
*
* @param string $file File path.
* @param int $width Image width.
* @param int $height Image height.
* @param bool $crop Optional. Whether to crop image to specified width and height or resize.
* Default false.
* @return false|array False, if no image was created. Metadata array on success.
*/
function image_make_intermediate_size( $file, $width, $height, $crop = false ) {
if ( $width || $height ) {
$editor = wp_get_image_editor( $file );
if ( is_wp_error( $editor ) || is_wp_error( $editor->resize( $width, $height, $crop ) ) ) {
return false;
}
$resized_file = $editor->save();
if ( ! is_wp_error( $resized_file ) && $resized_file ) {
unset( $resized_file['path'] );
return $resized_file;
}
}
return false;
}
/**
* Helper function to test if aspect ratios for two images match.
*
* @since 4.6.0
*
* @param int $source_width Width of the first image in pixels.
* @param int $source_height Height of the first image in pixels.
* @param int $target_width Width of the second image in pixels.
* @param int $target_height Height of the second image in pixels.
* @return bool True if aspect ratios match within 1px. False if not.
*/
function wp_image_matches_ratio( $source_width, $source_height, $target_width, $target_height ) {
/*
* To test for varying crops, we constrain the dimensions of the larger image
* to the dimensions of the smaller image and see if they match.
*/
if ( $source_width > $target_width ) {
$constrained_size = wp_constrain_dimensions( $source_width, $source_height, $target_width );
$expected_size = array( $target_width, $target_height );
} else {
$constrained_size = wp_constrain_dimensions( $target_width, $target_height, $source_width );
$expected_size = array( $source_width, $source_height );
}
// If the image dimensions are within 1px of the expected size, we consider it a match.
$matched = ( abs( $constrained_size[0] - $expected_size[0] ) <= 1 && abs( $constrained_size[1] - $expected_size[1] ) <= 1 );
return $matched;
}
/**
* Retrieves the image's intermediate size (resized) path, width, and height.
*
* The $size parameter can be an array with the width and height respectively.
* If the size matches the 'sizes' metadata array for width and height, then it
* will be used. If there is no direct match, then the nearest image size larger
* than the specified size will be used. If nothing is found, then the function
* will break out and return false.
*
* The metadata 'sizes' is used for compatible sizes that can be used for the
* parameter $size value.
*
* The url path will be given, when the $size parameter is a string.
*
* If you are passing an array for the $size, you should consider using
* add_image_size() so that a cropped version is generated. It's much more
* efficient than having to find the closest-sized image and then having the
* browser scale down the image.
*
* @since 2.5.0
*
* @param int $post_id Attachment ID.
* @param array|string $size Optional. Image size. Accepts any valid image size, or an array
* of width and height values in pixels (in that order).
* Default 'thumbnail'.
* @return false|array $data {
* Array of file relative path, width, and height on success. Additionally includes absolute
* path and URL if registered size is passed to $size parameter. False on failure.
*
* @type string $file Image's path relative to uploads directory
* @type int $width Width of image
* @type int $height Height of image
* @type string $path Image's absolute filesystem path.
* @type string $url Image's URL.
* }
*/
function image_get_intermediate_size( $post_id, $size = 'thumbnail' ) {
$imagedata = wp_get_attachment_metadata( $post_id );
if ( ! $size || ! is_array( $imagedata ) || empty( $imagedata['sizes'] ) ) {
return false;
}
$data = array();
// Find the best match when '$size' is an array.
if ( is_array( $size ) ) {
$candidates = array();
if ( ! isset( $imagedata['file'] ) && isset( $imagedata['sizes']['full'] ) ) {
$imagedata['height'] = $imagedata['sizes']['full']['height'];
$imagedata['width'] = $imagedata['sizes']['full']['width'];
}
foreach ( $imagedata['sizes'] as $_size => $data ) {
// If there's an exact match to an existing image size, short circuit.
if ( intval( $data['width'] ) === intval( $size[0] ) && intval( $data['height'] ) === intval( $size[1] ) ) {
$candidates[ $data['width'] * $data['height'] ] = $data;
break;
}
// If it's not an exact match, consider larger sizes with the same aspect ratio.
if ( $data['width'] >= $size[0] && $data['height'] >= $size[1] ) {
// If '0' is passed to either size, we test ratios against the original file.
if ( 0 === $size[0] || 0 === $size[1] ) {
$same_ratio = wp_image_matches_ratio( $data['width'], $data['height'], $imagedata['width'], $imagedata['height'] );
} else {
$same_ratio = wp_image_matches_ratio( $data['width'], $data['height'], $size[0], $size[1] );
}
if ( $same_ratio ) {
$candidates[ $data['width'] * $data['height'] ] = $data;
}
}
}
if ( ! empty( $candidates ) ) {
// Sort the array by size if we have more than one candidate.
if ( 1 < count( $candidates ) ) {
ksort( $candidates );
}
$data = array_shift( $candidates );
/*
* When the size requested is smaller than the thumbnail dimensions, we
* fall back to the thumbnail size to maintain backward compatibility with
* pre 4.6 versions of WordPress.
*/
} elseif ( ! empty( $imagedata['sizes']['thumbnail'] ) && $imagedata['sizes']['thumbnail']['width'] >= $size[0] && $imagedata['sizes']['thumbnail']['width'] >= $size[1] ) {
$data = $imagedata['sizes']['thumbnail'];
} else {
return false;
}
// Constrain the width and height attributes to the requested values.
list( $data['width'], $data['height'] ) = image_constrain_size_for_editor( $data['width'], $data['height'], $size );
} elseif ( ! empty( $imagedata['sizes'][ $size ] ) ) {
$data = $imagedata['sizes'][ $size ];
}
// If we still don't have a match at this point, return false.
if ( empty( $data ) ) {
return false;
}
// include the full filesystem path of the intermediate file
if ( empty( $data['path'] ) && ! empty( $data['file'] ) && ! empty( $imagedata['file'] ) ) {
$file_url = wp_get_attachment_url( $post_id );
$data['path'] = path_join( dirname( $imagedata['file'] ), $data['file'] );
$data['url'] = path_join( dirname( $file_url ), $data['file'] );
}
/**
* Filters the output of image_get_intermediate_size()
*
* @since 4.4.0
*
* @see image_get_intermediate_size()
*
* @param array $data Array of file relative path, width, and height on success. May also include
* file absolute path and URL.
* @param int $post_id The post_id of the image attachment
* @param string|array $size Registered image size or flat array of initially-requested height and width
* dimensions (in that order).
*/
return apply_filters( 'image_get_intermediate_size', $data, $post_id, $size );
}
/**
* Gets the available intermediate image sizes.
*
* @since 3.0.0
*
* @return array Returns a filtered array of image size strings.
*/
function get_intermediate_image_sizes() {
$default_sizes = array( 'thumbnail', 'medium', 'medium_large', 'large' );
$additional_sizes = wp_get_additional_image_sizes();
if ( ! empty( $additional_sizes ) ) {
$default_sizes = array_merge( $default_sizes, array_keys( $additional_sizes ) );
}
/**
* Filters the list of intermediate image sizes.
*
* @since 2.5.0
*
* @param array $default_sizes An array of intermediate image sizes. Defaults
* are 'thumbnail', 'medium', 'medium_large', 'large'.
*/
return apply_filters( 'intermediate_image_sizes', $default_sizes );
}
/**
* Returns a normalized list of all currently registered image sub-sizes.
*
* @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.
*/
function wp_get_registered_image_subsizes() {
$additional_sizes = wp_get_additional_image_sizes();
$all_sizes = array();
foreach ( get_intermediate_image_sizes() as $size_name ) {
$size_data = array(
'width' => 0,
'height' => 0,
'crop' => false,
);
if ( isset( $additional_sizes[ $size_name ]['width'] ) ) {
// For sizes added by plugins and themes.
$size_data['width'] = intval( $additional_sizes[ $size_name ]['width'] );
} else {
// For default sizes set in options.
$size_data['width'] = intval( get_option( "{$size_name}_size_w" ) );
}
if ( isset( $additional_sizes[ $size_name ]['height'] ) ) {
$size_data['height'] = intval( $additional_sizes[ $size_name ]['height'] );
} else {
$size_data['height'] = intval( get_option( "{$size_name}_size_h" ) );
}
if ( empty( $size_data['width'] ) && empty( $size_data['height'] ) ) {
// This size isn't set.
continue;
}
if ( isset( $additional_sizes[ $size_name ]['crop'] ) ) {
$size_data['crop'] = $additional_sizes[ $size_name ]['crop'];
} else {
$size_data['crop'] = get_option( "{$size_name}_crop" );
}
if ( ! is_array( $size_data['crop'] ) || empty( $size_data['crop'] ) ) {
$size_data['crop'] = (bool) $size_data['crop'];
}
$all_sizes[ $size_name ] = $size_data;
}
return $all_sizes;
}
/**
* Retrieve an image to represent an attachment.
*
* A mime icon for files, thumbnail or intermediate size for images.
*
* The returned array contains four values: the URL of the attachment image src,
* the width of the image file, the height of the image file, and a boolean
* representing whether the returned array describes an intermediate (generated)
* image size or the original, full-sized upload.
*
* @since 2.5.0
*
* @param int $attachment_id Image attachment ID.
* @param string|array $size Optional. Image size. Accepts any valid image size, or an array of width
* and height values in pixels (in that order). Default 'thumbnail'.
* @param bool $icon Optional. Whether the image should be treated as an icon. Default false.
* @return false|array Returns an array (url, width, height, is_intermediate), or false, if no image is available.
*/
function wp_get_attachment_image_src( $attachment_id, $size = 'thumbnail', $icon = false ) {
// get a thumbnail or intermediate image if there is one
$image = image_downsize( $attachment_id, $size );
if ( ! $image ) {
$src = false;
if ( $icon ) {
$src = wp_mime_type_icon( $attachment_id );
if ( $src ) {
/** This filter is documented in wp-includes/post.php */
$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/media' );
$src_file = $icon_dir . '/' . wp_basename( $src );
@list( $width, $height ) = getimagesize( $src_file );
}
}
if ( $src && $width && $height ) {
$image = array( $src, $width, $height );
}
}
/**
* Filters the image src result.
*
* @since 4.3.0
*
* @param array|false $image Either array with src, width & height, icon src, or false.
* @param int $attachment_id Image attachment ID.
* @param string|array $size Size of image. Image size or array of width and height values
* (in that order). Default 'thumbnail'.
* @param bool $icon Whether the image should be treated as an icon. Default false.
*/
return apply_filters( 'wp_get_attachment_image_src', $image, $attachment_id, $size, $icon );
}
/**
* Get an HTML img element representing an image attachment
*
* While `$size` will accept an array, it is better to register a size with
* add_image_size() so that a cropped version is generated. It's much more
* efficient than having to find the closest-sized image and then having the
* browser scale down the image.
*
* @since 2.5.0
*
* @param int $attachment_id Image attachment ID.
* @param string|array $size Optional. Image size. Accepts any valid image size, or an array of width
* and height values in pixels (in that order). Default 'thumbnail'.
* @param bool $icon Optional. Whether the image should be treated as an icon. Default false.
* @param string|array $attr Optional. Attributes for the image markup. Default empty.
* @return string HTML img element or empty string on failure.
*/
function wp_get_attachment_image( $attachment_id, $size = 'thumbnail', $icon = false, $attr = '' ) {
$html = '';
$image = wp_get_attachment_image_src( $attachment_id, $size, $icon );
if ( $image ) {
list($src, $width, $height) = $image;
$hwstring = image_hwstring( $width, $height );
$size_class = $size;
if ( is_array( $size_class ) ) {
$size_class = join( 'x', $size_class );
}
$attachment = get_post( $attachment_id );
$default_attr = array(
'src' => $src,
'class' => "attachment-$size_class size-$size_class",
'alt' => trim( strip_tags( get_post_meta( $attachment_id, '_wp_attachment_image_alt', true ) ) ),
);
$attr = wp_parse_args( $attr, $default_attr );
// Generate 'srcset' and 'sizes' if not already present.
if ( empty( $attr['srcset'] ) ) {
$image_meta = wp_get_attachment_metadata( $attachment_id );
if ( is_array( $image_meta ) ) {
$size_array = array( absint( $width ), absint( $height ) );
$srcset = wp_calculate_image_srcset( $size_array, $src, $image_meta, $attachment_id );
$sizes = wp_calculate_image_sizes( $size_array, $src, $image_meta, $attachment_id );
if ( $srcset && ( $sizes || ! empty( $attr['sizes'] ) ) ) {
$attr['srcset'] = $srcset;
if ( empty( $attr['sizes'] ) ) {
$attr['sizes'] = $sizes;
}
}
}
}
/**
* Filters the list of attachment image attributes.
*
* @since 2.8.0
*
* @param array $attr Attributes for the image markup.
* @param WP_Post $attachment Image attachment post.
* @param string|array $size Requested size. Image size or array of width and height values
* (in that order). Default 'thumbnail'.
*/
$attr = apply_filters( 'wp_get_attachment_image_attributes', $attr, $attachment, $size );
$attr = array_map( 'esc_attr', $attr );
$html = rtrim( " $value ) {
$html .= " $name=" . '"' . $value . '"';
}
$html .= ' />';
}
return $html;
}
/**
* Get the URL of an image attachment.
*
* @since 4.4.0
*
* @param int $attachment_id Image attachment ID.
* @param string|array $size Optional. Image size to retrieve. Accepts any valid image size, or an array
* of width and height values in pixels (in that order). Default 'thumbnail'.
* @param bool $icon Optional. Whether the image should be treated as an icon. Default false.
* @return string|false Attachment URL or false if no image is available.
*/
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;
}
/**
* Get the attachment path relative to the upload directory.
*
* @since 4.4.1
* @access private
*
* @param string $file Attachment file name.
* @return string Attachment path relative to the upload directory.
*/
function _wp_get_attachment_relative_path( $file ) {
$dirname = dirname( $file );
if ( '.' === $dirname ) {
return '';
}
if ( false !== strpos( $dirname, 'wp-content/uploads' ) ) {
// Get the directory name relative to the upload directory (back compat for pre-2.7 uploads)
$dirname = substr( $dirname, strpos( $dirname, 'wp-content/uploads' ) + 18 );
$dirname = ltrim( $dirname, '/' );
}
return $dirname;
}
/**
* Get the image size as array from its meta data.
*
* Used for responsive images.
*
* @since 4.4.0
* @access private
*
* @param string $size_name Image size. Accepts any valid image size name ('thumbnail', 'medium', etc.).
* @param array $image_meta The image meta data.
* @return array|bool Array of width and height values in pixels (in that order)
* or false if the size doesn't exist.
*/
function _wp_get_image_size_from_meta( $size_name, $image_meta ) {
if ( $size_name === 'full' ) {
return array(
absint( $image_meta['width'] ),
absint( $image_meta['height'] ),
);
} elseif ( ! empty( $image_meta['sizes'][ $size_name ] ) ) {
return array(
absint( $image_meta['sizes'][ $size_name ]['width'] ),
absint( $image_meta['sizes'][ $size_name ]['height'] ),
);
}
return false;
}
/**
* Retrieves the value for an image attachment's 'srcset' attribute.
*
* @since 4.4.0
*
* @see wp_calculate_image_srcset()
*
* @param int $attachment_id Image attachment ID.
* @param array|string $size Optional. Image size. Accepts any valid image size, or an array of
* width and height values in pixels (in that order). Default 'medium'.
* @param array $image_meta Optional. The image meta data as returned by 'wp_get_attachment_metadata()'.
* Default null.
* @return string|bool A 'srcset' value string or false.
*/
function wp_get_attachment_image_srcset( $attachment_id, $size = 'medium', $image_meta = null ) {
$image = wp_get_attachment_image_src( $attachment_id, $size );
if ( ! $image ) {
return false;
}
if ( ! is_array( $image_meta ) ) {
$image_meta = wp_get_attachment_metadata( $attachment_id );
}
$image_src = $image[0];
$size_array = array(
absint( $image[1] ),
absint( $image[2] ),
);
return wp_calculate_image_srcset( $size_array, $image_src, $image_meta, $attachment_id );
}
/**
* 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.
*
* @since 4.5.0
*
* @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 = 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 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 || ! 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, ', ' );
}
/**
* Retrieves the value for an image attachment's 'sizes' attribute.
*
* @since 4.4.0
*
* @see wp_calculate_image_sizes()
*
* @param int $attachment_id Image attachment ID.
* @param array|string $size Optional. Image size. Accepts any valid image size, or an array of width
* and height values in pixels (in that order). Default 'medium'.
* @param array $image_meta Optional. The image meta data as returned by 'wp_get_attachment_metadata()'.
* Default null.
* @return string|bool A valid source size value for use in a 'sizes' attribute or false.
*/
function wp_get_attachment_image_sizes( $attachment_id, $size = 'medium', $image_meta = null ) {
$image = wp_get_attachment_image_src( $attachment_id, $size );
if ( ! $image ) {
return false;
}
if ( ! is_array( $image_meta ) ) {
$image_meta = wp_get_attachment_metadata( $attachment_id );
}
$image_src = $image[0];
$size_array = array(
absint( $image[1] ),
absint( $image[2] ),
);
return wp_calculate_image_sizes( $size_array, $image_src, $image_meta, $attachment_id );
}
/**
* Creates a 'sizes' attribute value for an image.
*
* @since 4.4.0
*
* @param array|string $size Image size to retrieve. Accepts any valid image size, or an array
* of width and height values in pixels (in that order). Default 'medium'.
* @param string $image_src Optional. The URL to the image file. Default null.
* @param array $image_meta Optional. The image meta data as returned by 'wp_get_attachment_metadata()'.
* Default null.
* @param int $attachment_id Optional. Image attachment ID. Either `$image_meta` or `$attachment_id`
* is needed when using the image size name as argument for `$size`. Default 0.
* @return string|bool A valid source size value for use in a 'sizes' attribute or false.
*/
function wp_calculate_image_sizes( $size, $image_src = null, $image_meta = null, $attachment_id = 0 ) {
$width = 0;
if ( is_array( $size ) ) {
$width = absint( $size[0] );
} elseif ( is_string( $size ) ) {
if ( ! $image_meta && $attachment_id ) {
$image_meta = wp_get_attachment_metadata( $attachment_id );
}
if ( is_array( $image_meta ) ) {
$size_array = _wp_get_image_size_from_meta( $size, $image_meta );
if ( $size_array ) {
$width = absint( $size_array[0] );
}
}
}
if ( ! $width ) {
return false;
}
// Setup the default 'sizes' attribute.
$sizes = sprintf( '(max-width: %1$dpx) 100vw, %1$dpx', $width );
/**
* Filters the output of 'wp_calculate_image_sizes()'.
*
* @since 4.4.0
*
* @param string $sizes A source size value for use in a 'sizes' attribute.
* @param array|string $size Requested size. Image size or array of width and height values
* in pixels (in that order).
* @param string|null $image_src The URL to the image file or null.
* @param array|null $image_meta The image meta data as returned by wp_get_attachment_metadata() or null.
* @param int $attachment_id Image attachment ID of the original image or 0.
*/
return apply_filters( 'wp_calculate_image_sizes', $sizes, $size, $image_src, $image_meta, $attachment_id );
}
/**
* Filters 'img' elements in post content to add 'srcset' and 'sizes' attributes.
*
* @since 4.4.0
*
* @see wp_image_add_srcset_and_sizes()
*
* @param string $content The raw post content to be filtered.
* @return string Converted content with 'srcset' and 'sizes' attributes added to images.
*/
function wp_make_content_images_responsive( $content ) {
if ( ! preg_match_all( '/]+>/', $content, $matches ) ) {
return $content;
}
$selected_images = array();
$attachment_ids = array();
foreach ( $matches[0] as $image ) {
if ( false === strpos( $image, ' srcset=' ) && preg_match( '/wp-image-([0-9]+)/i', $image, $class_id ) ) {
$attachment_id = absint( $class_id[1] );
if ( $attachment_id ) {
/*
* If exactly the same image tag is used more than once, overwrite it.
* All identical tags will be replaced later with 'str_replace()'.
*/
$selected_images[ $image ] = $attachment_id;
// Overwrite the ID when the same image is included more than once.
$attachment_ids[ $attachment_id ] = true;
}
}
}
if ( count( $attachment_ids ) > 1 ) {
/*
* Warm the object cache with post and meta information for all found
* images to avoid making individual database calls.
*/
_prime_post_caches( array_keys( $attachment_ids ), false, true );
}
foreach ( $selected_images as $image => $attachment_id ) {
$image_meta = wp_get_attachment_metadata( $attachment_id );
$content = str_replace( $image, wp_image_add_srcset_and_sizes( $image, $image_meta, $attachment_id ), $content );
}
return $content;
}
/**
* Adds 'srcset' and 'sizes' attributes to an existing 'img' element.
*
* @since 4.4.0
*
* @see wp_calculate_image_srcset()
* @see wp_calculate_image_sizes()
*
* @param string $image An HTML 'img' element to be filtered.
* @param array $image_meta The image meta data as returned by 'wp_get_attachment_metadata()'.
* @param int $attachment_id Image attachment ID.
* @return string Converted 'img' element with 'srcset' and 'sizes' attributes added.
*/
function wp_image_add_srcset_and_sizes( $image, $image_meta, $attachment_id ) {
// Ensure the image meta exists.
if ( empty( $image_meta['sizes'] ) ) {
return $image;
}
$image_src = preg_match( '/src="([^"]+)"/', $image, $match_src ) ? $match_src[1] : '';
list( $image_src ) = explode( '?', $image_src );
// Return early if we couldn't get the image source.
if ( ! $image_src ) {
return $image;
}
// Bail early if an image has been inserted and later edited.
if ( preg_match( '/-e[0-9]{13}/', $image_meta['file'], $img_edit_hash ) &&
strpos( wp_basename( $image_src ), $img_edit_hash[0] ) === false ) {
return $image;
}
$width = preg_match( '/ width="([0-9]+)"/', $image, $match_width ) ? (int) $match_width[1] : 0;
$height = preg_match( '/ height="([0-9]+)"/', $image, $match_height ) ? (int) $match_height[1] : 0;
if ( ! $width || ! $height ) {
/*
* If attempts to parse the size value failed, attempt to use the image meta data to match
* the image file name from 'src' against the available sizes for an attachment.
*/
$image_filename = wp_basename( $image_src );
if ( $image_filename === wp_basename( $image_meta['file'] ) ) {
$width = (int) $image_meta['width'];
$height = (int) $image_meta['height'];
} else {
foreach ( $image_meta['sizes'] as $image_size_data ) {
if ( $image_filename === $image_size_data['file'] ) {
$width = (int) $image_size_data['width'];
$height = (int) $image_size_data['height'];
break;
}
}
}
}
if ( ! $width || ! $height ) {
return $image;
}
$size_array = array( $width, $height );
$srcset = wp_calculate_image_srcset( $size_array, $image_src, $image_meta, $attachment_id );
if ( $srcset ) {
// Check if there is already a 'sizes' attribute.
$sizes = strpos( $image, ' sizes=' );
if ( ! $sizes ) {
$sizes = wp_calculate_image_sizes( $size_array, $image_src, $image_meta, $attachment_id );
}
}
if ( $srcset && $sizes ) {
// Format the 'srcset' and 'sizes' string and escape attributes.
$attr = sprintf( ' srcset="%s"', esc_attr( $srcset ) );
if ( is_string( $sizes ) ) {
$attr .= sprintf( ' sizes="%s"', esc_attr( $sizes ) );
}
// Add 'srcset' and 'sizes' attributes to the image markup.
$image = preg_replace( '/]+?)[\/ ]*>/', '', $image );
}
return $image;
}
/**
* Adds a 'wp-post-image' class to post thumbnails. Internal use only.
*
* Uses the {@see 'begin_fetch_post_thumbnail_html'} and {@see 'end_fetch_post_thumbnail_html'}
* action hooks to dynamically add/remove itself so as to only filter post thumbnails.
*
* @ignore
* @since 2.9.0
*
* @param array $attr Thumbnail attributes including src, class, alt, title.
* @return array Modified array of attributes including the new 'wp-post-image' class.
*/
function _wp_post_thumbnail_class_filter( $attr ) {
$attr['class'] .= ' wp-post-image';
return $attr;
}
/**
* Adds '_wp_post_thumbnail_class_filter' callback to the 'wp_get_attachment_image_attributes'
* filter hook. Internal use only.
*
* @ignore
* @since 2.9.0
*
* @param array $attr Thumbnail attributes including src, class, alt, title.
*/
function _wp_post_thumbnail_class_filter_add( $attr ) {
add_filter( 'wp_get_attachment_image_attributes', '_wp_post_thumbnail_class_filter' );
}
/**
* Removes the '_wp_post_thumbnail_class_filter' callback from the 'wp_get_attachment_image_attributes'
* filter hook. Internal use only.
*
* @ignore
* @since 2.9.0
*
* @param array $attr Thumbnail attributes including src, class, alt, title.
*/
function _wp_post_thumbnail_class_filter_remove( $attr ) {
remove_filter( 'wp_get_attachment_image_attributes', '_wp_post_thumbnail_class_filter' );
}
add_shortcode( 'wp_caption', 'img_caption_shortcode' );
add_shortcode( 'caption', 'img_caption_shortcode' );
/**
* Builds the Caption shortcode output.
*
* Allows a plugin to replace the content that would otherwise be returned. The
* filter is {@see 'img_caption_shortcode'} and passes an empty string, the attr
* parameter and the content parameter values.
*
* The supported attributes for the shortcode are 'id', 'caption_id', 'align',
* '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.
*
* @param array $attr {
* Attributes of the caption shortcode.
*
* @type string $id ID of the image and caption container element, i.e. `