Why is my ajax request getting response 0?

Question

I\'ve setup the basic wordpress ajax example in my wp theme. The trigger is made by modernizr.js checking the media queries on the page.

jQuery(document).rea         


        

Answer 1

Add the "exit" end of the function as shown below, this will fix the return 0 with the response in WordPress on using the ajax request.

add_action('wp_ajax_nopriv_getStateList', 'getStateList');
add_action('wp_ajax_getStateList', 'getStateList');

function getStateList() {
    global $wpdb;
    $countryId = $_POST['countryId'];
    $results = $wpdb->get_results("SELECT id,name FROM regions where country_id ='".$countryId."' ");
    echo json_encode(array('status'=>200,'data'=>$results));
    exit;
}

Answer 2

Everything has to match here:

PHP

add_action('wp_ajax_my_action',        'my_action');
add_action('wp_ajax_nopriv_my_action', 'my_action');

function my_action() {}

JS

var data = {
    action: 'my_action',
    whatever: ajax_object.we_value 
};

Also, you're missing security checks and a better handling of the response.
Check this examples: [ 1 ] and [ 2 ].

Answer 3

Here is the full example to solve this issue:

JavaScript:

$(document).ready(function() {
    $("#submit").click(function(e) {
        var demo = 'demo';
        var ajaxurl = '<?php echo admin_url("admin-ajax.php", null); ?>';
        data = { action: "data_insert", demo: demo};     
        $.ajax({
            url: ajaxurl,
            data: data,
            dataType: 'json',
            type: 'post',
            success: function(response) {
              console.log(response);  
            }
        });
    });    
});

PHP:

add_action('wp_ajax_data_insert', 'data_insert');
add_action('wp_ajax_nopriv_data_insert', 'data_insert');
function data_insert() {
    $data = $_POST['demo'];
    echo json_encode($data);
    die();
}