wp_localize_script not create variable in head section

Question

I try to make an ajax function in wordpress and I enqueued my script and declared my variables like this in functions.php:

function my_enqueue_scripts() {
    wp_enqueue_script(
        'load_post', 
        get_template_directory_uri() . '/js/load_post.js', 
        array( 'jquery' ), 
        '1.0', 
        1
    );
    wp_localize_script( 
        'load_post', 
        'wp_ajax',
        array( 
            'url' => admin_url( 'admin-ajax.php' ), 
            'nonce' => wp_create_nonce( 'ajax_nonce' )
        )
    );
}
add_action('wp_enqueue_scripts', 'my_enqueue_scripts');

load_post.js :

jQuery(document).ready(function($) { 

    jQuery('#next-container').click(function($) {

        var $container = jQuery('#isotope-container');
        var IDs = [];
        jQuery(".element").each(function($){ IDs.push(this.id); });

        jQuery('#next-container').html('loading');

        jQuery.ajax({
            type: 'POST',
            url: wp_ajax.url,
            dataType: 'html',
            data: {  action: 'load_post',  
                     ajax_nonce: wp_ajax.nonce,
                     post_ids: IDs,  
                  },  //{'post_ids[]': IDs },
            success: function(data) {
                    jQuery('#next-container').html(''); 
                    $container.isotope( 'insert', $(data)); 
                    }
        })
    })
})

However in my load_post.js I can't get wp_ajax variable. I don't see any variable added in the head section of my source code in google chrome or IE.

Where comes from my problem? Do I miss something?

Answer 1

Your code looks correct.
alert(wp_ajax.nonce); should display the nonce.
You can also verify the existence of the wp_ajax object via console.log(wp_ajax) in your browser's Javascript console.

wp_localize_script adds the object(s) to the footer (a call to wp_footer() should be present in the theme's footer.php file).
It'll look like so:

<script type="text/javascript">
    /* <![CDATA[ */
    var wp_ajax = {"url":"http://example.com","nonce":"123XYZ"};
    /* ]]> */
</script>