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

Question

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!

Answer 1

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
    });