Restrict Default Image to One Post Type

This is a solution I’m sharing since I couldn’t find a direct answer.

GOAL: Restrict the default image to a single post type

I modified code from janw.oostendorp, and it works. I’m adding it for future searchers.

function dfi_custom_posttypes( $dfi_id, $post_id ) {
	$post = get_post( $post_id );

	// remove null featured image ID for all post types except "post"
	if ( $post->post_type !== 'post' ) {
	    return null; // return no image selection.
	}

	return $dfi_id; // the original featured image id
}

add_filter( 'dfi_thumbnail_id', 'dfi_custom_posttypes', 10, 2 );

I’m not an advanced programmer, so if there’s a better way, please let me know.

Thanks for the great plugin.