AngularJs has "Services" and "Factories" just for problems like yours.These are used to have something global between Controllers, Directives, Other Services or any other angularjs components..You can defined functions, store data, make calculate functions or whatever you want inside Services and use them in AngularJs Components as Global.like
angular.module('MyModule', [...])
.service('MyService', ['$http', function($http){
return {
users: [...],
getUserFriends: function(userId){
return $http({
method: 'GET',
url: '/api/user/friends/' + userId
});
}
....
}
}])
if you need more
Find More About Why We Need AngularJs Services and Factories