Controllers using same function

Question

I have a function that two controllers will be using, and instead of both of them having the same source code for the same function, I want it in one place and just inject the controller parameters (or perhaps the controller itself this). These three may exist in three separate files/modules.

.controller('FirstCtrl', function() {
 this.search = function(this) {
 find(this);
 };
});
.controller('SecondCtrl', function() {
 this.seek = function(this) {
 find(this);
 };
});
var find = function(controller) {
 .
 .
 .
};

Is this the best way? How about if I have services in my controllers like $http or $scope, and the function find would depend on these services? How do I inject these angular specific services to a plain JavaScript function not defined in an AngularJS module?

Answer 1

There are a few ways to do it; one may be:

.factory("findMixin", function() {
 return {
 find: function() {
 // your implementation; `this` will be the controller
 }
 };
})
.controller("SomeCtrl", ["$scope", "findMixin", function($scope, findMixin) {
 angular.extend(this, findMixin);
 // here `this`, i.e. the controller, has received the methods from the mixin
 ...
})

The same principle (angular.extend) can be applied to the $scope, if you want find to be mixed into the scope.

Answer 2

You can add a service:

.factory('find', [ function() {
 return function(controller, scope) {
 // ...
 };
}]);

And inject it into the controllers:

.controller('FirstCtrl', ['find', function(find) {
 this.search = function(this) {
 find(this);
 };
}]);
.controller('SecondCtrl', ['find', function(find) {
 this.seek = function(this) {
 find(this);
 };
}]);

• oikonomiyaki: Thanks. And how about when function find would need a service specific to the controller, say $scope? How do I go about doing that?
• Dennis Traub: @menorah84 You can inject the $scope into the service factory as well: .factory('find', ['$scope', function($scope) { ... }]);. I updated the answer.
• Marian Ban: as i know you can't inject $scope into a service or factory. The only scope you can inject is a $rootScope.
• Dennis Traub: @MajoB Ah yes, didn't think of that. But it should be as easy as sending the current scope as an argument.