how to install underscore.js in my angular application?

Question

I used yo-angular to generate my angularjs template with bootstrap/grunt/bower. I also want to use underscore in the app:

npm install underscore --save-dev

In the MainCtrl I am calling underscore.js just to see whether it works:

angular.module('yomanApp')
  .controller('MainCtrl', function ($scope) {
    $scope.awesomeThings = [
      'HTML5 Boilerplate',
      'AngularJS',
      'AngularJS'
    ];

    _.each([1,2,3],console.log);
  });

When I run the application with Chrome I get this errmsg in the console:

ReferenceError: _ is not defined
    at new <anonymous> (http://localhost:9000/scripts/controllers/main.js:18:5)
    at invoke (http://localhost:9000/bower_components/angular/angular.js:4203:17)
    at Object.instantiate (http://localhost:9000/bower_components/angular/angular.js:4211:27)
    at http://localhost:9000/bower_components/angular/angular.js:8501:28
    at link (http://localhost:9000/bower_components/angular-route/angular-route.js:975:26)
    at invokeLinkFn (http://localhost:9000/bower_components/angular/angular.js:8258:9)
    at nodeLinkFn (http://localhost:9000/bower_components/angular/angular.js:7768:11)
    at compositeLinkFn (http://localhost:9000/bower_components/angular/angular.js:7117:13)
    at publicLinkFn (http://localhost:9000/bower_components/angular/angular.js:6996:30)
    at $get.boundTranscludeFn (http://localhost:9000/bower_components/angular/angular.js:7135:16) <div ng-view="" class="ng-scope">

After this error I added the module to the app config: 'use strict';

/**
 * @ngdoc overview
 * @name yomanApp
 * @description
 * # yomanApp
 *
 * Main module of the application.
 */
angular
  .module('yomanApp', [
    'ngAnimate',
    'ngCookies',
    'ngResource',
    'ngRoute',
    'ngSanitize',
    'ngTouch',
    'underscore'

  ])
  .config(function ($routeProvider) {
    $routeProvider
      .when('/', {
        templateUrl: 'views/main.html',
        controller: 'MainCtrl'
      })
      .when('/about', {
        templateUrl: 'views/about.html',
        controller: 'AboutCtrl'
      })
      .when('/accordeon', {
        templateUrl: 'views/accordeon.html',
        controller: 'IssuesCtrl'
      })
      .otherwise({
        redirectTo: '/'
      });
  });

Now I am getting this error:

Uncaught Error: [$injector:modulerr] Failed to instantiate module yomanApp due to:
Error: [$injector:modulerr] Failed to instantiate module underscore due to:
Error: [$injector:nomod] Module 'underscore' is not available! You either misspelled the module name or forgot to load it. If registering a module ensure that you specify the dependencies as the second argument.

Last thing I tried was adding it to the index.html:

<script src="node_modules/underscore/underscore.js"></script>

This results in the same error as above. Also get a 404 for the underscore.js?? Is this a grunt configuration issue or anything else?

Answer 1

I tend to just use a constant for this type of thing. It's a simple approach and allows you to explicitly state your dependencies in your application.

Install with bower:

bower install underscore --save

Load the library before angular:

<script src="bower_components/underscore/underscore.js"></script>
<script src="bower_components/angular/angular.js"></script>
<script src="app/scripts/app.js"></script>

Define it as a constant (in app/scripts/app.js for example):

application.constant('_',
    window._
);

Then in your controllers/services:

application.controller('Ctrl', function($scope, _) {
    //Use underscore here like any other angular dependency
    var stooges = [{name: 'moe', age: 40}, {name: 'larry', age: 50}, {name: 'curly', age: 60}];
    $scope.names = _.pluck(stooges, 'name');
});

Answer 2

Create a module with the name of underscore a module and then you can pass it in your application and it will be accessible. Currently the underscore module is undefined and hence you are getting this errror.

Your app becomes like this:

    var underscore = angular.module('underscore', []);
        underscore.factory('_', function() {
            return window._; //Underscore should be loaded on the page
        });

       angular
      .module('yomanApp', [
        'ngAnimate',
        'ngCookies',
        'ngResource',
        'ngRoute',
        'ngSanitize',
        'ngTouch',
        'underscore'

      ])
      .config(function ($routeProvider) {
        $routeProvider
          .when('/', {
            templateUrl: 'views/main.html',
            controller: 'MainCtrl'
          })
          .when('/about', {
            templateUrl: 'views/about.html',
            controller: 'AboutCtrl'
          })
          .when('/accordeon', {
            templateUrl: 'views/accordeon.html',
            controller: 'IssuesCtrl'
          })
          .otherwise({
            redirectTo: '/'
          });
      })
.controller('MainCtrl', function ($scope, _) {
    $scope.awesomeThings = [
      'HTML5 Boilerplate',
      'AngularJS',
      'AngularJS'
    ];

    _.each([1,2,3],console.log);
  });