Title: How do you overwrite a core function?
Last modified: August 19, 2016

---

# How do you overwrite a core function?

 *  [Spencer Hill](https://wordpress.org/support/users/ws5f3dj7/)
 * (@ws5f3dj7)
 * [15 years, 11 months ago](https://wordpress.org/support/topic/how-do-you-overwrite-a-core-function/)
 * Heya,
    I need to overwrite this function, can someone tell me what I’m doing 
   wrong because this isn’t working:
 *     ```
       // THIS FUNCTION OVERWRITES THE ONE THAT ORIGINATES IN WP-INCLUDES/LINK-TEMPLATE.PHP AT LINE 298 TO REMOVE THE FILENAME FROM THE END OF THE "Post URL" BUTTON
       function modified_get_attachment_link($id = false) {
       	global $post, $wp_rewrite;
   
       	$link = false;
   
       	if ( ! $id)
       		$id = (int) $post->ID;
   
       	$object = get_post($id);
       	if ( $wp_rewrite->using_permalinks() && ($object->post_parent > 0) && ($object->post_parent != $id) ) {
       		$parent = get_post($object->post_parent);
       		if ( 'page' == $parent->post_type )
       			$parentlink = _get_page_link( $object->post_parent ); // Ignores page_on_front
       		else
       			$parentlink = get_permalink( $object->post_parent );
   
       		if ( is_numeric($object->post_name) || false !== strpos(get_option('permalink_structure'), '%category%') )
       			$name = 'attachment/' . $object->post_name; // <permalink>/<int>/ is paged so we use the explicit attachment marker
       		else
       			$name = $object->post_name;
   
       		if ( strpos($parentlink, '?') === false )
       			$link = user_trailingslashit( trailingslashit($parentlink) );
       	}
   
       	if ( ! $link )
       		$link = home_url( "/?attachment_id=$id" );
   
       	return apply_filters('attachment_link', $link, $id);
       }
   
       add_filter('get_attachment_link', 'modified_get_attachment_link', 1, 2);
       ```
   

Viewing 4 replies - 1 through 4 (of 4 total)

 *  [surfgatinho](https://wordpress.org/support/users/surfgatinho/)
 * (@surfgatinho)
 * [15 years, 3 months ago](https://wordpress.org/support/topic/how-do-you-overwrite-a-core-function/#post-1557656)
 * Hi,
 * Did you ever work this out. I’ve just spent a day banging my head against the
   wall trying to overwrite exactly the same function. Trying to make gallery thumbs
   into page links.
 * Would really appreciate it if you could help.
 * Thanks
 *  [yetimade2](https://wordpress.org/support/users/yetimade2/)
 * (@yetimade2)
 * [15 years, 2 months ago](https://wordpress.org/support/topic/how-do-you-overwrite-a-core-function/#post-1557659)
 * I’ve been trying to overwrite this for two hours.
 * remove_all_filters(‘the_attachment_link’, ‘wp_get_attachment_link’);
    remove_all_actions(‘
   the_attachment_link’, ‘wp_get_attachment_link’); remove_action(‘the_attachment_link’,‘
   wp_get_attachment_link’); remove_action(‘wp_get_attachment_link’);
 * I’ve tried EVERYTHING. Nothing works.
 * So, if anyone answers to this, it will help both of us.
 * – JC
 *  [yetimade2](https://wordpress.org/support/users/yetimade2/)
 * (@yetimade2)
 * [15 years, 2 months ago](https://wordpress.org/support/topic/how-do-you-overwrite-a-core-function/#post-1557660)
 * See, sorta similar.
 * Should work, but doesn’t.
 *     ```
       //deactivate WordPress function
       remove_all_actions( 'wp_get_attachment_link' );
       //activate own function
       add_action('yetimade_wp_get_attachment_link');
       //the own renamed function
       function yetimade_wp_get_attachment_link($id = 0, $size = 'thumbnail', $permalink = false, $icon = false, $text = false) {
       	$id = intval($id);
       	$_post = & get_post( $id );
   
       	if ( ('attachment' != $_post->post_type) || !$url = wp_get_attachment_url($_post->ID) )
       		return __('Missing Attachment');
   
       	if ( $permalink )
       		$url = get_attachment_link($_post->ID);
   
       	$post_title = esc_attr($_post->post_title);
   
       	if ( $text ) {
       		$link_text = esc_attr($text);
       	} elseif ( ( is_int($size) && $size != 0 ) or ( is_string($size) && $size != 'none' ) or $size != false ) {
       		$link_text = wp_get_attachment_image($id, $size, $icon);
       	} else {
       		$link_text = '';
       	}
   
       	if( trim($link_text) == '' )
       		$link_text = $_post->post_title;
   
       	return apply_filters( 'wp_get_attachment_link', "$link_text", $id, $size, $permalink, $icon, $text );
       }
       ```
   
 * You guys get anywhere with yours?
 *  [nnh](https://wordpress.org/support/users/nnh/)
 * (@nnh)
 * [15 years, 1 month ago](https://wordpress.org/support/topic/how-do-you-overwrite-a-core-function/#post-1557663)
 * Hey,
 * I tried something like this for the media gallery and it works for me :
 *     ```
       add_filter('media_upload_gallery', 'fnc_dummy_redirect',0);
       function fnc_dummy_redirect()
       {
       	remove_all_filters( 'media_upload_gallery');
               my_overrided_media_upload_gallery_function();
       }
       ```
   
 * Not a beautiful solution, but at least the core files remain intact.
 * nnh

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘How do you overwrite a core function?’ is closed to new replies.

 * 4 replies
 * 4 participants
 * Last reply from: [nnh](https://wordpress.org/support/users/nnh/)
 * Last activity: [15 years, 1 month ago](https://wordpress.org/support/topic/how-do-you-overwrite-a-core-function/#post-1557663)
 * Status: not resolved

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