Check if a module is enabled with JavaScript

Question

How do I check if a module is enabled using JavaScript? I want to avoid unnecessary Ajax calls that cause 403 errors since the module is not enabled.

if (mymodule_exist) {
  // Make an Ajax call.
  jQuery.ajax({
    url: "/player/status",
    type: "POST",
    async: false,
    success: function(data) {
      player_value = data;
    }
  });
}

I am trying to do something like this. How do I do it efficiently?

Answer 1

You can check module is enabled or not using module_exists function... Ideally your .module which checks for above condition and sets variable for JavaScript file goes below..

See detailed steps below on adding this condition

• Create a folder called 'custom' in sites/all/modules
• Create a folder called 'mycustomjs' in above custom folder
• Create a file called 'mycustomjs.info' inside above folder with

below code

name = My Custom JS Alters
description = A custom module to interact with JS
core = 7.x
package = Custom

Create a file called mycustomjs.module inside 'mycustomjs' folder with below code

<?php

function mycustomjs_preprocess_page(&$vars) {
  $module = "MODULENAME"; // Change modulename to module you want to verify
  $does_module_enabled = module_exists($module);
  if ($does_module_enabled) {
    drupal_add_js(array('MODULENAME' => array('enabled' => TRUE)), 'setting');
  }
  else {
    drupal_add_js(array('MODULENAME' => array('enabled' => FALSE)), 'setting');
  }  
}

?>

For more information See the Creating Drupal 7.x modules if you're not sure

Answer 2

I can think of two ways:

• Send a JavaScript flag as settings, indicating the module is active:

  drupal_add_js(array('my_module' => array('enabled' => TRUE)), 'setting');
  

• If the module is enabled, modify the output in some way so the JavaScript code that makes the petition is included only when your module is enabled, or the contrary way, make sure that code is not included if your module is disabled: you will have to use another module or some kind of configuration. The exact way depends on the origin of the JavaScript code that makes the Ajax petitions.