Scales an image to fit a particular size (such as ‘thumb’ or ‘medium’).
Description
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 ‘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 normally returned from the function.
Parameters
$idintrequired- Attachment ID for image.
$sizestring|int[]optional- Image size. Accepts any registered image size name, or an array of width and height values in pixels (in that order). Default
'medium'.Default:
'medium'
Source
* @type int $1 Image width in pixels. * @type int $2 Image height in pixels. * @type bool $3 Whether the image is a resized image. * } */ function image_downsize( $id, $size = 'medium' ) { $is_image = wp_attachment_is_image( $id ); /** * Filters whether to preempt the output of image_downsize(). * * Returning a truthy value from the filter will effectively short-circuit * down-sizing the image, returning that value instead. * * @since 2.5.0 * * @param bool|array $downsize Whether to short-circuit the image downsize. * @param int $id Attachment ID for image. * @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). */ $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']['full'] ) ) { $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 ( 'thumbnail' === $size && ! empty( $meta['thumb'] ) && is_string( $meta['thumb'] ) ) { // Fall back to the old thumbnail. $imagefile = get_attached_file( $id ); $thumbfile = str_replace( wp_basename( $imagefile ), wp_basename( $meta['thumb'] ), $imagefile ); if ( file_exists( $thumbfile ) ) { $info = wp_getimagesize( $thumbfile ); if ( $info ) { $img_url = str_replace( $img_url_basename, wp_basename( $thumbfile ), $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 ); Changelog
| Version | Description |
|---|---|
| 2.5.0 | Introduced. |
Add a function to select medium attachment images
Maybe you already know wp_get_attachment_thumb_url() ;. Now I’m showing how to do the same thing to return the url for the medium sized attachment.
$id is the ID of the attachment. This can be really useful for plugins like WP-Choose-Thumb. With this function you can get the medium sized previews.