function get_lastpostmodified with feed updates on custom post types

[Frumph]

Trying to figure out how to add_filter to the get_ladpostmodified so that when custom-post-types are updated it will recognize the feed is updated.

However from what I can see in that plugin the filter only allows you to modify the return data from the wpdb and not the actual sql statement?

Any advice?

[Utkarsh]

How about

 add_filter('get_lastpostmodified', 'my_lastpostmodified');
function my_lastpostmodified()
{
    global $wpdb;
    $add_seconds_server = date('Z');
    return $wpdb->get_var("SELECT  DATE_ADD(post_modified_gmt, INTERVAL '$add_seconds_server' SECOND) FROM $wpdb->posts WHERE post_status = 'publish' ORDER  BY post_modified_gmt DESC LIMIT 1");
} 
  

[Frumph]

^ awesome, however does this add to the wp_cache_set so that the feed retains it's cache'ing or will this happen every feed load?

[Utkarsh]

^ awesome, however does this add to the wp_cache_set so that the feed retains it's cache'ing or will this happen every feed load?

 add_filter('get_lastpostmodified', 'my_lastpostmodified');
function my_lastpostmodified()
{
    $lastpostmodified = wp_cache_get( "lastpostmodified:custom:server", 'timeinfo' );
    if ( $lastpostmodified ) return $lastpostmodified;
    global $wpdb;
    $add_seconds_server = date('Z');
    $lastpostmodified = $wpdb->get_var("SELECT  DATE_ADD(post_modified_gmt, INTERVAL '$add_seconds_server' SECOND) FROM $wpdb->posts WHERE post_status = 'publish' ORDER  BY post_modified_gmt DESC LIMIT 1");
    wp_cache_set( "lastpostmodified:custom:server", $lastpostmodified, 'timeinfo' );
    return $lastpostmodified;
} 
  

[Frumph]

That is great Utkarsh thank you, would make a great blog post on adding custom post types to feeds if you made one ;)