Gallery Shortcode: using link attribute to link to a specific image size

Question

When [gallery link="file"] is used, it calls the original image file source.

It it possible to create a shortcode filter that links to a specific size, like:

[gallery link="medium"]

or

[gallery link="custom-size-name"] (referring to an additional image size created with add_image_size() in functions.php.)

Answer 1

I found something very close that works here:

http://oikos.org.uk/2011/09/tech-notes-using-resized-images-in-wordpress-galleries-and-lightboxes/

Answer 2

You obviously didn't look in the Codex before you asked this. Check out Gallery Shortcode from within the Codex. You can set the attribute size to whatever you want.

Answer 3

Short of de-registering the built in shortcode tag, copying the function and re-registering it with some modifications you could filter on wp_get_attachment_link. The problem is this affects everywhere that function is used.

Saying that it might not be such a bad thing:

add_filter( 'wp_get_attachment_link', 'my_attachment_link', 10, 6 );
function my_attachment_link( $link, $id, $size, $permalink, $icon, $text ) {
    if ( !is_admin() ) {
        // if we're linking to the file itself
        if ( ! $permalink )
            $link = preg_replace("/href=\'([^\']+)\'/", "href='" . wp_get_attachment_image_src( $id, 'my-custom-size', false ) . "'", $link );
    }
    return $link;
}

This will override any links generated to the original size file on the front end with a link to the size you specify in the second argument in wp_get_attachment_image_src().