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I am relatively new to jQuery and AJAX in particular. I have a small issue with the return value always being 0, though I think this is actually the success message and it's not returning anything.

I have scoured the Google-verse and I have the die() function on the PHP callback and I believe the add_actions are correct.

I am working on a local host, though I doubt that affects it and this is all in the admin, not front end. I also checked that the js is enqueued and localised.

I get a 200 OK message in the chrome developer area.

I also tested out the basic AJAX from http://codex.wordpress.org/AJAX_in_Plugins and it also returned 0, which makes me wonder if it is something other than the code outlined below.

Right now I am just trying to make it send something back to the jQuery. Any help would be appreciated.

The jQuery

    jQuery('.cl_link_buttons').val('id').click(function() {

            var currentid = jQuery(this).attr('id');


            jQuery.ajax ( data = {
                action: 'cleanlinks_ajax_get_post_data',
                url: ajaxurl,
                type: 'POST',
                dataType: 'text',
                "currentid" : currentid


            jQuery.post(ajaxurl, data, function(response) {

                var dataz = response;
                alert( dataz );
                console.log (dataz); //show json in console


            return false;

    }); //end click event
}); //end doc ready


add_action("wp_ajax_cleanlinks_ajax_get_post_data", "cleanlinks_ajax_get_post_data");
add_action("wp_ajax_nopriv_cleanlinks_ajax_get_post_data", "cleanlinks_ajax_get_post_data");

function cleanlinks_ajax_get_post_data() {

$from_ajax =  $_POST['currentid'];

echo "do" . $from_ajax . "something";


share|improve this question
Have you verified that ajaxurl is set properly? –  Andrew Bartel Apr 27 '13 at 15:14
Does your browser console show any errors? If so, what are they? –  s_ha_dum Apr 27 '13 at 15:17
jQuery('.cl_link_buttons').val('id').click(function() looks odd. –  toscho Apr 27 '13 at 15:26
Andrew, yes I believe it is correct, the request url in Chrome Inspector is showing domain/wp-admin/admin-ajax.php –  Apina Apr 27 '13 at 17:08
@s_ha_dum No errors showing –  Apina Apr 27 '13 at 17:10

6 Answers 6

A 0 response means either that the action is not set (in the ajax data) or that the action's callback function cannot be found.

share|improve this answer
Yeah, this is the correct answer. All adding die() to the end does, is terminate the script. That answer is technically correct if you're seeing 0 appended to the END of the output, however if all you get is '0', then it means nothing was returned, and you have an error as described in this answer. –  Hybrid Web Dev May 11 '14 at 20:26

What you have to do is add die();at the end of your function.

See it here: http://codex.wordpress.org/AJAX_in_Plugins

It worked for me.

share|improve this answer
This is the answer to the WP AJAX 0 problem. –  BenRacicot Mar 26 '14 at 15:59

I got same problem. And solved it. You must send "action" variable like in example:

var dataString = {lat: '55.56', lng: '25.35', action:'report_callback'};
        url: "http://domain.net/wp-admin/admin-ajax.php",  
        type: "POST",
        //some times you cant try this method for sending action variable
        //action : 'report_callback',
        success: function(data){ 

        error: function() {

Because in wp-admin/admin-ajax.php is handler for action variable:

if ( empty( $_REQUEST['action'] ) ) {...}
Line 26
share|improve this answer
The OP does send an action parameter. While this may have worked for you it was not the problem here. –  s_ha_dum May 11 '14 at 20:19

Try running this code on the console

jQuery.post(ajaxurl, {action:'cleanlinks_ajax_get_post_data'}, function(response) {
     console.log (response);

I can see many things wrong about your JavaScript code and that might be the reason.

share|improve this answer
Well it is coming up with a lot of things I dont fully understand. What I do understand: ReadyState 4, status 200, responseText "0". And then it comes up with the response 0. If there something in specific I should be looking for here? If there are issues with the code, please point them out and I can look into them, I am still learning jQuery. –  Apina Apr 27 '13 at 17:34
do you have your site running live? –  Omar Abid Apr 27 '13 at 17:35
No, it's localhost –  Apina Apr 27 '13 at 17:36
Hard to tell. Could you try running console.info(ajaxurl); and see what it gives? –  Omar Abid Apr 27 '13 at 17:37
/wp-admin/admin-ajax.php is the response edit -- /wp-admin/admin-ajax.php undefined –  Apina Apr 27 '13 at 17:45
up vote -2 down vote accepted

So I worked it out. It was not the jQuery as such though I have improved that, it was the placement of the call back function. I moved it over to the main plugin file and it worked.

share|improve this answer
can you show how did you do it ? –  Francisco Corrales Morales Jan 27 '14 at 20:39
I am having this same issue, could you show how you fixed this? –  Jeremy Mar 8 '14 at 18:31
Another answer is here: wordpress.stackexchange.com/a/131397 @Jeremy –  Francisco Corrales Morales Mar 26 '14 at 16:22

Try adding an if statement:

function my_function(){
$id = $_POST['variation_id'];

    if(isset($_POST['variation_id'])) { 

//your coded function


}// end function
share|improve this answer
How would that solve the problem? Note the accepted answer and the original code. –  toscho Sep 23 '13 at 2:28

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