Title: Bug? post_gallery filter parameter always empty string Last modified: August 19, 2016 --- # Bug? post_gallery filter parameter always empty string * Resolved [cannibalsmith](https://wordpress.org/support/users/cannibalsmith/) * (@cannibalsmith) * [17 years, 1 month ago](https://wordpress.org/support/topic/bug-post_gallery-filter-parameter-always-empty-string/) * In `functions.php` of my custom theme: * ``` function custom_gallery($attr) { /* .. */ } add_action('post_gallery', 'custom_gallery'); ``` * The `$attr` is always an empty string. But it should be an array. When I look at the `wp-includes/media.php` line 597: * ``` function gallery_shortcode($attr) { global $post; // Allow plugins/themes to override the default gallery template. $output = apply_filters('post_gallery', '', $attr); ``` * It seems to be a bug. [But then again…](http://core.trac.wordpress.org/ticket/6954) * What to do? How do I obtain proper `$attr` value? Viewing 3 replies - 1 through 3 (of 3 total) * [esmi](https://wordpress.org/support/users/esmi/) * (@esmi) * [17 years, 1 month ago](https://wordpress.org/support/topic/bug-post_gallery-filter-parameter-always-empty-string/#post-1041791) * The `$attr` value comes from the gallery shortcode. If you look around 10 lines further down in `wp-includes/media.php`, you’ll see: * ``` extract(shortcode_atts(array( 'order' => 'ASC', 'orderby' => 'menu_order ID', 'id' => $post->ID, 'itemtag' => 'dl', 'icontag' => 'dt', 'captiontag' => 'dd', 'columns' => 3, 'size' => 'thumbnail' ), $attr)); ``` * So your custom_gallery function could use exactly the same `extract` function but you can now insert your own gallery ordering and markup etc. I use a similar custom gallery function to output the final gallery as an unordered list and stop the gallery CSS from being rendered within the `` of a page (which** is** a bug). * [Justin Tadlock](https://wordpress.org/support/users/greenshady/) * (@greenshady) * [17 years, 1 month ago](https://wordpress.org/support/topic/bug-post_gallery-filter-parameter-always-empty-string/#post-1041919) * The current gallery code in WP is correct. You should be using the filter hook to customize the gallery: * ``` add_filter( 'post_gallery', 'my_gallery_shortcode', 10, 2 ); function my_gallery_shortcode( $output, $attr ) { /* Custom gallery shortcode. */ } ``` * Thread Starter [cannibalsmith](https://wordpress.org/support/users/cannibalsmith/) * (@cannibalsmith) * [17 years, 1 month ago](https://wordpress.org/support/topic/bug-post_gallery-filter-parameter-always-empty-string/#post-1042003) * Thanks, greenshady. My mistake was not passing `$accepted_args` to `add_filter`. Viewing 3 replies - 1 through 3 (of 3 total) The topic ‘Bug? post_gallery filter parameter always empty string’ is closed to new replies. ## Tags * [gallery](https://wordpress.org/support/topic-tag/gallery/) * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/) * 3 replies * 3 participants * Last reply from: [cannibalsmith](https://wordpress.org/support/users/cannibalsmith/) * Last activity: [17 years, 1 month ago](https://wordpress.org/support/topic/bug-post_gallery-filter-parameter-always-empty-string/#post-1042003) * Status: resolved ## Topics ### Topics with no replies ### Non-support topics ### Resolved topics ### Unresolved topics ### All topics