Angular getting unknown provider error when injecting service into controller

Question

I'm working on a project that uses IIFE, a concept that I'm still beginning to grasp. My service seems to be fine, I'm using some Jasmine to determine that it is being defined, but when I try to inject it into my controller I get this error:

Unknown provider: StudentsServiceProvider <- StudentsService <- StudentsController

here is the controller in question:

(function() {
    'use strict';

    angular
        .module('ngInterview.students')
        .controller('StudentsController', StudentsController);

    StudentsController.$inject = ['StudentsService'];
    function StudentsController(StudentsService) {

        /**
         * Model
         */

        var vm = this;

        /**
         * Initialization
         */

        activate();

        /**
         * Implementations
         */

        function activate() {
            // Initialization code goes here
            vm.students = StudentsService.getStudents();
        }
    }
})();

And here is the service, just in case I messed up in there somehow:

(function() {
    'use strict';

    angular
        .module('ngInterview.api.students')
        .service('StudentsService', StudentsService);

    StudentsService.$inject = ['$http'];
    function StudentsService($http) {

        /**
         * Exposed functions
         */

        this.getName = getName; // This function serves no purpose. It's just here as an example.

        this.getStudents = function() {
            return $http({
                url: "CUSTOM_URL_HERE",
                method: "GET"
            }).then(function successCallback(res) {
                return res;
            }, function errorCallback(res) {
                return this.getStudents();
            });
        }

        /**
         * Implementations
         */

        function getName() {
            return 'studentsService';
        }
    }
})();

All of the files listed above are included in the index.html. If I take out the references to StudentsService, I get no errors and all of the files get instantiated correctly.

Answer 1

Since the service StudentsService is in another module, you have to inject the 'ngInterview.api.students' module in the main module, as below:

angular
  .module('ngInterview.students', ['ngInterview.api.students'])