How to check if a directive or controller is avail

Question

In angularjs, given a module, how do you check if a directive/controller exists given a module.

I have a module and I want to know if some particular directives have been loaded. Below is some sample code:

var module = angular.module('myModule');
//check if controller exists
if (module.hasController('my.first.controller')){
   //do something
}
if (module.hasDirective('my.first.directive')){
   //do something
}

I have implemented this in a way. Looking for a better way of doing it if it is available by default.

Is this possible? If so, how do you do this?

Answer 1

Use this code to check if a service exists.

$injector.has('myServiceName')

To check if a directive exists, you must add a Directive suffix after the directive name:

$injector.has('myDirectiveNameDirective')

Answer 2

    var controllers = [];

    _.each(app._invokeQueue, function(value, index) {
        if (value[0] !== '$controllerProvider') {
            return;
        }

        controllers.push(value[2][0]);
    });

    if (controllers.indexOf('controller-i-want') === - 1) {
        // controller is undefined
    }

Answer 3

Solved the problem by writing a wrapper function that is called to load the controllers and stuff and at such I'm able to tell when each directive is loaded.

Answer 4

I found some working code here

angular.service('ControllerChecker', ['$controller', function($controller) {
    return {
        exists: function(controllerName) {
            if(typeof window[controllerName] == 'function') {
                return true;
            }
            try {
                $controller(controllerName);
                return true;
            } catch (error) {
                return !(error instanceof TypeError);
            }
        }
    };
}]);

JSFiddle: http://jsfiddle.net/fracz/HB7LU/6780/