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I'm calling a "loop handler" kind of php file that opens a loop with WP_Query.

Inside the foreach loop I want to use the show_postdata function. I'm aware of the global $post aspect of this function. I tried placing the global $post everywhere in that php file without success though.

I get an error 500 server error with noch detailed error message in the catch part.

When I use the class to get data on the server inside a template it works.

This is my AJAX call:

    type       : "GET",
    data       : {numPosts : numPosts, postTypes : postTypes, template : template, postID : null, filterArgs : filterArgs, fields: fields, inclMeta : inclMeta, imgFields : imgFields },
    dataType   : "html",
    url        : bfApp.setWPUrl + "/bfLoopHandler.php",
    beforeSend : function(){
    success    : function(data){

        if (typeof(callbackSuccess) == "function") {

    error     : function(jqXHR, textStatus, errorThrown) {

        if (typeof(callbackError) == "function") {
            callbackError(jqXHR, textStatus, errorThrown);


This is an excerpt from the php file up to the point where show_postdata is called:

class bfLoop {
public function getData($postIDs, $postTypes, $numPosts, $filterArgs, $template, $fields, $inclMeta, $imgFields, $inclCats) {

    global $post;

    define('WP_USE_THEMES', false);
    $parse_uri = explode( 'wp-content', $_SERVER['SCRIPT_FILENAME'] );
    require_once( str_replace('index.php', '', $parse_uri[0]) . 'wp-load.php' );

    // Argumente setzen
    if ($postIDs == null || $postIDs == 0) {
        $args = array( 'post_type' => $postTypes, 
                       'post_status' => array('publish'),
                       'posts_per_page' => $numPosts, 
                       'meta_query' => $filterArgs,
                       'fields' => $idsOnly );
    } else {
        if (is_array($postIDs)) {
            $args = array(
            'post__in' => $postIDs,
            'post_type' => 'any');                  
        } else {
            $args = array(
            'p' => $postIDs,
            'post_type' => 'any');                

    $loop = new WP_Query( $args );  

        $retArray = array();

        $posts = $loop->get_posts();   
        foreach ( $posts as $post ) {

            try {
               setup_postdata( $post ); 
            } catch(Exception $e) {
                //return "AFTER";
                return "W:" . $e->getMessage();
            } ......
share|improve this question
Don't make AJAX calls like that in WordPress. The correct way to make AJAX calls within WordPress is here: codex.wordpress.org/AJAX_in_Plugins – cale_b Apr 30 '14 at 13:46
I know. This is existing code i have to work with. Is there a way regardless the "wrong" approach? – Matthias Max Apr 30 '14 at 13:54
Can you indicate in the code where it's not working? I think you'd still have better luck refactoring this into the correct method. You'll spend less time, the code will work right in the proper WP context, and it'll be right when you are done. – cale_b Apr 30 '14 at 14:19
The code works exactly up to the line with the show_postdata command. I have checked this with a sample return value. When using this class without AJAX it also works (instantiated inside a template). You might be right, but the idea to have the right line just at the right place is also interesting ;-) the whole theme I have here is not using WP typical architecture so its difficult to find the "starting point" of refactoring... – Matthias Max Apr 30 '14 at 14:30
So this is not a question anymore? – toscho Apr 30 '14 at 16:02
up vote 0 down vote accepted

Solved by getting author, post_date, permalink & excerpt manually without setup_postdata:

        $excerpt = myCustomExcerptFunction($post, 35);
        $post->post_excerpt = $excerpt;

        // Permalinks
        $post->post_permalink = get_post_permalink($post->ID);

        // Author
        $authorObjekt = get_userdata($post->post_author);
        $post->post_author_displayname = $authorObjekt->data->display_name;
        $post->post_author_nicename = $authorObjekt->data->user_nicename;

        // Date
        $post->post_date_wpformat = date_i18n( get_option( 'date_format' ), 
share|improve this answer

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