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Nik So
Nik So

Reputation: 16821

Angular.js: Is .value() the proper way to set app wide constant and how to retrieve it in a controller

Hi there I was watching a couple of the angular.js videos and saw that the value() method was used to set a kind of module-wide constant. for example, one can set the Angular-UI library's config like so: (coffeescript)

angular.module('app',[])
.value "ui.config", 
  tinymce:
    theme: 'simple'
    width: '500'
    height: '300'

And my app is currently looking like this:

window.app = angular.module("app", [ 'ui'])

.config(["$routeProvider", ($routeProvider) ->
  $routeProvider
  .when "/users",
    templateUrl: "assets/templates/users/index.html"
    controller: IndexUsersCtrl

  .otherwise redirectTo: "/users"

])

.value 'csrf', $('meta[name="csrf-token"]').attr('content') #<---- attention here

IndexUsersCtrl = ($scope) ->
  $scope.users = gon.rabl
  console.log "I want to log the csrf value here" #<---- then attention
IndexUsersCtrl.$inject = ['$scope']

But I can't seem to get that value by tapping into the 'app' variable which is corresponding to the app module.

I read up here on ST and over on angularjs's google group that one way to share common code btwn controllers is through a service, will this concept apply here, too?

Thanks!

Upvotes: 90

Views: 96023

Answers (3)

Ben Lesh
Ben Lesh

Reputation: 108491

Module.value(key, value) is used to inject an editable value, Module.constant(key, value) is used to inject a constant value

The difference between the two isn't so much that you "can't edit a constant", it's more that you can't intercept a constant with $provide and inject something else.

// define a value
app.value('myThing', 'weee');

// define a constant
app.constant('myConst', 'blah');

// use it in a service
app.factory('myService', ['myThing', 'myConst', function(myThing, myConst){
   return {
       whatsMyThing: function() { 
          return myThing; //weee
       },
       getMyConst: function () {
          return myConst; //blah
       }
   };
}]);

// use it in a controller
app.controller('someController', ['$scope', 'myThing', 'myConst', 
    function($scope, myThing, myConst) {
        $scope.foo = myThing; //weee
        $scope.bar = myConst; //blah
    });

Upvotes: 150

Dan Doyon
Dan Doyon

Reputation: 6720

You need to reference csrf in your controller IndexUsersCtrl = ( $scope, csrf ) 

IndexUsersCtrl.$inject = [ '$scope', 'csrf' ]

Upvotes: 2

SnapShot
SnapShot

Reputation: 5544

I recently wanted to use this feature with Karma inside a test. As Dan Doyon points out the key is that you would inject a value just like a controller, service, etc. You can set .value to many different types - strings, arrays of objects, etc. For example:

myvalues.js a file containing value - make sure it is including in your karma conf file

var myConstantsModule = angular.module('test.models', []);
myConstantModule.value('dataitem', 'thedata');
// or something like this if needed
myConstantModule.value('theitems', [                                                                                                                                                                                                             
  {name: 'Item 1'},                                                                                                                                                                                                                         
  {name: 'Item 2'},                                                                                                                                                                                                                         
  {name: 'Item 3'}
]);

]);

test/spec/mytest.js - maybe this is a Jasmine spec file loaded by Karma

describe('my model', function() {
    var theValue;
    var theArray;
    beforeEach(module('test.models'));
    beforeEach(inject(function(dataitem,theitems) {
      // note that dataitem is just available
      // after calling module('test.models')
      theValue = dataitem;
      theArray = theitems;
    });
    it('should do something',function() {
      // now you can use the value in your tests as needed
      console.log("The value is " + theValue);
      console.log("The array is " + theArray);
    });
});

Upvotes: 4

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