get_adjacent_post WordPress
/*
* Replacement for get_adjacent_post()
*
* This supports only the custom post types you identify and does not
* look at categories anymore. This allows you to go from one custom post type
* to another which was not possible with the default get_adjacent_post().
* Orig: wp-includes/link-template.php
*
* @param string $direction: Can be either 'prev' or 'next'
* @param multi $post_types: Can be a string or an array of strings
*/
function mod_get_adjacent_post($direction = 'prev', $post_types = 'post') {
global $post, $wpdb;
if(empty($post)) return NULL;
if(!$post_types) return NULL;
if(is_array($post_types)){
$txt = '';
for($i = 0; $i <= count($post_types) - 1; $i++){
$txt .= "'".$post_types[$i]."'";
if($i != count($post_types) - 1) $txt .= ', ';
}
$post_types = $txt;
}
$current_post_date = $post->post_date;
$join = '';
$in_same_cat = FALSE;
$excluded_categories = '';
$adjacent = $direction == 'prev' ? 'previous' : 'next';
$op = $direction == 'prev' ? '<' : '>';
$order = $direction == 'prev' ? 'DESC' : 'ASC';
$join = apply_filters( "get_{$adjacent}_post_join", $join, $in_same_cat, $excluded_categories );
$where = apply_filters( "get_{$adjacent}_post_where", $wpdb->prepare("WHERE p.post_date $op %s AND p.post_type IN({$post_types}) AND p.post_status = 'publish'", $current_post_date), $in_same_cat, $excluded_categories );
$sort = apply_filters( "get_{$adjacent}_post_sort", "ORDER BY p.post_date $order LIMIT 1" );
$query = "SELECT p.* FROM $wpdb->posts AS p $join $where $sort";
$query_key = 'adjacent_post_' . md5($query);
$result = wp_cache_get($query_key, 'counts');
if ( false !== $result )
return $result;
$result = $wpdb->get_row("SELECT p.* FROM $wpdb->posts AS p $join $where $sort");
if ( null === $result )
$result = '';
wp_cache_set($query_key, $result, 'counts');
return $result;
}
Innocent Ibis
