wp_ajax function return the html page

Question

I´m trying to do a plugin feature : download a file by a button click using wp_ajax feature.

I already used wp_ajax but in this case I did not find my error. When I click on the button, it runs correctly the js file, but return the html page instead to call getPrivateFileByAjax().

JS

jQuery( function($) {
    $(document).ready( function() {
        $(".download-file").on( "click", function( event ) {
            var file_name = $(this).attr("data-file");
            var data = {
                'action': "getPrivateFileByAjax",
                'file_name' : file_name
            };
            $.post( wgs_ajax_object.ajaxurl, data, function( response ) {
                console.dir( response );
            });
        });
    });
});

My Shortcode page

class FileDownloadsShortcode extends Shortcode {

    public function check_page() {
        global $post;

         if( !empty( $post ) && has_shortcode( $post->post_content, $this->tag ) ){
            add_action('wp_enqueue_scripts', array( $this , 'set_scripts'));
        }
    }

    public function set_scripts() {

        //Javascripts
        wp_enqueue_script( "downloadsscript", "path-to-my-js.js" );
        wp_localize_script( 'downloadsscript', 'wgs_ajax_object',
             array( 'ajax_url' => admin_url( 'admin-ajax.php' ) ) 
        );
    }

}

Admin init file

class Admin extends FooPlugin {

    public function __construct() {
         parent::__construct();
         add_action( "wp_ajax_getPrivateFileByAjax", array( $this, "getPrivateFileByAjax" ) );
         add_action( "wp_ajax_nopriv_getPrivateFileByAjax", array( $this, "getPrivateFileByAjax" ) );
     }

     public static function getPrivateFileByAjax(){
        echo "test";
        wp_die();
     }

}

Answer 1

My error was in my JS file.

I had to write wgs_ajax_object.ajax_url instead of wgs_ajax_object.ajaxurl