WordPress admin-ajax returns “0” on the Viewer-Facing Side

Question

I'm pretty new in Wordpress plugins, so I have a question for you guys. I have a problem with admin-ajax call on the viewer-facing side of site. I'm using shortcodes in wordpress posts, to make a link, which must call ajax action. Unfortunately admin-ajax.php returns 0 every single time. Take a look on my code and maybe you can help me to discover what i'm doing wrong.

PHP side:

class myClass {

    public function __construct() {
        if (defined('DOING_AJAX')) {
            add_action( 'wp_ajax_myAction', array($this, 'myCallback') );
            add_action( 'wp_ajax_nopriv_myAction', array($this, 'myCallback') );
        }
    }

    public function myCallback() {
        echo "test";
        die();
    }
}

and there is Ajax call in Javascript:

jQuery(document).ready(function($) {
    var link = $('a.myLink');
    link.on('click', function(e) {
        $.ajax({
            url: 'http://127.0.0.1/myapp/wp-admin/admin-ajax.php',
            type: 'POST',
            data: 'myAction',
            success:function(data) {
                console.log(data);
            },
            error: function(error) {
                console.log(error);
            }
        });   
    });
});

Do you have some ideas why that code isn't working and admin-ajax.php returns "0"?

Answer 1

Try to use the ajax call in this format :

jQuery(document).ready(function($) {
    var link = $('a.myLink');
    link.on('click', function(e) {
       var details = {
            'action': 'myAction'
        };

        $.ajax({
            url: 'http://127.0.0.1/myapp/wp-admin/admin-ajax.php',
            type: 'POST',
            data: details,  // data format
            success:function(data) {
                console.log(data);
            },
            error: function(error) {
                console.log(error);
            }
        });   
    });
});

hope it helps...

Answer 2

Solved! Two things:

data: 'myAction'

replaced by

data: {
    action: 'myAction'
}

and in main plugin file I had

if ( is_admin() ) {
    // there should be new myClass() too
} else {
    $class = new myClass();
}

thanks for suggestions!

Answer 3

Try with Enque JQuery Form Plugin Before Your Ajax request.

add_action('wp_print_scripts','include_jquery_form_plugin');
function include_jquery_form_plugin(){
        wp_enqueue_script( 'jquery' );
        wp_enqueue_script( 'jquery-form',array('jquery'),false,true ); 
}