Injecting modules in Angular at runtime - javascript

I have this Angular (1.3.15) code:
var my_app = angular.module('my_app', ["ui.bootstrap", "toastr"]);
my_app.module("template/foo/bar.html", []).run([$templateCache, function($templateCache) { /* ... global template ... */ }]);
which injects bootstrap and toastr libraries and creates a template that I use in all my other JS files.
Now, not all files need ui.bootstrap, but given the fact that I placed it in my global.js file (which is loaded with every page, no matter wat), Angular is complaining about missing libraries (ui.bootstrap).
My question is: can I inject ui.bootstrap only in the controllers I need it and leave my gobal.js like this:
var my_app = angular.module('my_app', ["toastr"]);
Also, this applies to quite some other libraries I'm currently loading in my global JS file, not only ui.bootstrap.

One approach to this is to split your code into multiple modules by some rule. This way only the modules that need ui.bootstrap will have it as a dependency, other won't.
If that's still not clean enough for you then you might want to take a look at Browserify

Related

maintainable way of injecting dependencies in angularjs

I am wondering how can I inject dependencies in more readable way in angular. I am more interested in AMD(requirejs) way. Like following:
define(function (require) {
var ModuleOne = require("ModuleOne"),
ModuleTwo = require("ModuleTwo");
var ThisModule = (function () {
// code here
})();
return ThisModule;
});
Is it possible to inject dependencies above way in angularjs or is there any better way to do it then current way in angularjs?
From the Angular JS official website
Angular modules solve the problem of removing global state from the
application and provide a way of configuring the injector. As opposed
to AMD or require.js modules, Angular modules don't try to solve the
problem of script load ordering or lazy script fetching. These goals
are orthogonal and both module systems can live side by side and
fulfil their goals.
Hence, purpose of both the libraries(RequireJS and AngularJS) is totally different. The dependency injection system built into AngularJS deals with the objects needed in a component; while dependency management in RequireJS deals with the modules or, JavaScript files.
In requireJS, Objects of loaded modules are cached and they are served when same modules are requested again. On the other hand, AngularJS maintains an injector with a list of names and corresponding objects. In this case, Object is served whenever it is referenced using the registered name.
Generally we inject dependencies in angularJS like
someModule.controller('MyController', function($scope,greeter){
});
If you want an alternative way to inject dependencies in angularJS, you may do something like.
var MyController = function($scope, greeter) {
// ...
}
MyController.$inject = ['$scope', 'greeter'];
someModule.controller('MyController', MyController);
Hope it helps!

Require pattern Browserify / Angular

I'm working in a project with angular and browserify, this is the first time for me to use this two tools together, so I would like some advice on which is the way to require files with browserify.
We may import those files in different ways, Until now I experimented this way:
Angular App:
app
_follow
- followController.js
- followDirective.js
- followService.js
- require.js
- app.js
For each folder with in the files for a plugin I created an require.js file and in it I require all the files of that folder. Like so:
var mnm = require('angular').module('mnm');
mnm.factory('FollowService', ['Restangular',require('./followService')]);
mnm.controller('FollowController',['$scope','FollowService',require('./followController')])
mnm.directive('mnmFollowers', ['FollowService',require('./followDirective')]);
and then require all require.js files in a unique file called app.js that will generate the bundle.js
Question:
This way to require the files can be a good structure, or it will have some problem when I need to test? I would like to see your way to achieve good structure with angular and browserify
AngularJS and browserify aren't, sadly, a great match. Certainly not like React and browserify, but I digress.
What has worked for me is having each file as an AngularJS module (because each file is already a CommonJS module) and having the files export their AngularJS module name.
So your example would look like this:
app/
app.js
follow/
controllers.js
directives.js
services.js
index.js
The app.js would look something like this:
var angular = require('angular');
var app = angular.module('mnm', [
require('./follow')
]);
// more code here
angular.bootstrap(document.body, ['mnm']);
The follow/index.js would look something like this:
var angular = require('angular');
var app = angular.module('mnm.follow', [
require('./controllers'),
require('./directives'),
require('./services')
]);
module.exports = app.name;
The follow/controllers.js would look something like this:
var angular = require('angular');
var app = angular.module('mnm.follow.controllers', [
require('./services'), // internal dependency
'ui.router' // external dependency from earlier require or <script/>
// more dependencies ...
]);
app.controller('FollowController', ['$scope', 'FollowService', function ...]);
// more code here
module.exports = app.name;
And so on.
The advantage of this approach is that you keep your dependencies as explicit as possible (i.e. inside the CommonJS module that actually needs them) and the one-to-one mapping between CommonJS module paths and AngularJS module names prevents nasty surprises.
The most obvious problem with your approach is that you're keeping the actual dependencies that will be injected separate from the function that expects them, so if a function's dependencies change, you have to touch two files instead of one. This is a code smell (i.e. a bad thing).
For testability either approach should work as Angular's module system is essentially a giant blob and importing two modules that both define the same name will override each other.
EDIT (two years later): Some other people (both here and elsewhere) have suggested alternative approaches so I should probably address them and what the trade-offs are:
Have one global AngularJS module for your entire app and just do requires for side-effects (i.e. don't have the sub-modules export anything but manipulate the global angular object).
This seems to be the most common solution but kind of flies in the face of having modules at all. This seems to be the most pragmatic approach however and if you're using AngularJS you're already polluting globals so I guess having purely side-effect based modules is the least of your architectural problems.
Concatenate your AngularJS app code before passing it to Browserify.
This is the most literal solution to "let's combine AngularJS and Browserify". It's a valid approach if you're starting from the traditional "just blindly concatenate your app files" position of AngularJS and want to add Browserify for third-party libs, so I guess that makes it valid.
As far as your app structure goes this doesn't really improve anything by adding Browserify, though.
Like 1 but with each index.js defining its own AngularJS sub-module.
This is the boilerplate approach suggested by Brian Ogden. This suffers from all the drawbacks of 1 but creates some semblance of hierarchy within AngularJS in that at least you have more than one AngularJS module and the AngularJS module names actually correspond to your directory structure.
However the major drawback is that you now have two sets of namespaces to worry about (your actual modules and your AngularJS modules) but nothing enforcing consistency between them. Not only do you have to remember to import the right modules (which again purely rely on side-effects) but you also have to remember to add them to all the right lists and add the same boilerplate to every new file. This makes refactoring incredibly unwieldy and makes this the worst option in my opinion.
If I had to chose today, I would go with 2 because it gives up all pretense of AngularJS and Browserify being able to be unified and just leaves both to do their own thing. Plus if you already have an AngularJS build system it literally just means adding an extra step for Browserify.
If you're not inheriting an AngularJS code base and want to know which approach works best for starting a new project instead: don't start a new project in AngularJS. Either pick Angular2 which supports a real module system out of the box, or switch to React or Ember which don't suffer from this problem.
I was trying to use browserify with Angular but found it got a bit messy. I didn't like the pattern of creating a named service / controller then requiring it from another location, e.g.
angular.module('myApp').controller('charts', require('./charts'));
The controller name / definition is in one file, but the function itself is in another. Also having lots of index.js files makes it really confusing if you lots of files open in an IDE.
So I put together this gulp plugin, gulp-require-angular which allows you write Angular using standard Angular syntax, all js files which contain angular modules and dependencies of angular modules which appear in your main module dependency tree are require()'d into a generated entry file, which you then use as your browserify entry file.
You can still use require() within your code base to pull in external libraries (e.g lodash) into services / filters / directives as needed.
Here's the latest Angular seed forked and updated to use gulp-require-angular.
I've used a hybrid approach much like pluma. I created ng-modules like so:
var name = 'app.core'
angular.module(name, [])
.service('srvc', ['$rootScope', '$http', require( './path/to/srvc' ))
.service('srvc2', ['$rootScope', '$http', require( './path/to/srvc2' ))
.config...
.etc
module.exports = name
I think the difference is that I don't define individual ng-modules as dependencies to the main ng-module, in this case I wouldn't define a Service as an ng-module and then list it as a dep of the app.core ng-module. I try to keep it as flat as possible:
//srvc.js - see below
module.exports = function( $rootScope, $http )
{
var api = {};
api.getAppData = function(){ ... }
api.doSomething = function(){ ... }
return api;
}
Regarding the comment of code-smell, I disagree. While it's an extra step, it allows for some great configurability in terms of testing against mock-services. For instance I use this quite a bit for testing agains services that might not have an existing server-API ready:
angular.module(name, [])
// .service('srvc', ['$rootScope', '$http', require( './path/to/srvc' ))
.service('srvc', ['$rootScope', '$http', require( './path/to/mockSrvc' ))
So any controller or object dependent on srvc doesn't know which it is getting. I could see this getting a bit convoluted in terms of services being dependent on other services, but that to me is bad design. I prefer to use ng's event system to communicate betw. services so that you keep their coupling down.
Alan Plum's answer is just not a great answer or at least not a great demonstration of CommonJS modules and Browserify with Angular. The claim that Browserify does not mix well with Angular, compared to React is just not true.
Browserify and a CommonJS module pattern work great with Angular, allowing you to organize by features instead of types, keep vars out of global scope and share Angular Modules across apps easily. Not to mention you do not need to ever add a single <script> to your HTML ever again thanks to Browserify finding all your dependencies.
What is particular flawed in Alan Plum's answer is not letting requires in each index.js for each folder dictate dependencies for Angular modules, controllers, services, configurations, routes etc. There is no need for a single require in the Angular.module instantiation, nor a single module.exports as in the context that Alan Plum's answer suggests.
See here for a better module pattern for Angular using Browserify: https://github.com/Sweetog/yet-another-angular-boilerplate

Concatenate modules in RequireJS

I am using RequireJS to modularize my code. The website I am using will have several distinct page categories. For each one of them I want to load general JS file with all the dependencies that exist across all page categories, jQuery being most obvious one. I have managed to do that already.
For the rest of the pages, I want to have separate JS files. Each page has its own module but I am thinking that it would make more sense if I download several pages modules all at once and this way when the user comes to other pages, he will have the JS file already cached and won't have to download.
For now I tried to concatenate these modules which did work rather well. However, I am not sure how to load the specific module from a file. So far I am doing this:
require(['./js/common'], function (common) {
require(['public']);
});
common is the dependencies file and public is my concatenated file with all the dependencies. Inside it has modules for each page but I don't know how to call a specific one. Any ideas?
Take a look at the bundles option for RequireJS' runtime configuration. In your case it would be something like:
bundles: {
public: ['mod1', 'mod2', ...]
}
I've used mod1, mod2 because I don't see the name of the actual modules in your question but what you'd want there are the names of the modules inside the public bundle and that you want to load individually. With this, RequireJS will know that when you want to load such module, it has to get them from public instead of searching for them indivdually.
Then you should be able to change your loading code to:
require(['./js/common'], function (common) {
require(['mod1']);
});
Again, mod1 is for illustration.
Take a look at require-lazy.
It allows you to bundle independent parts of the application into separate bundles. From the developer's point of view, instead of:
define(["module1", "module2"], function(module1, module2) {...});
you write:
define(["lazy!module1", "lazy!module2"], function(module1, module2) {...});
Modules 1 & 2 will not be loaded upfront; they and their dependencies will be loaded lazilly when you call:
module1.get().then(function(realModule1) {
// here you have access to the real module1
});
Check out the examples for a few use cases.

How let users to access requirejs modules outside main?

I'm implementing an AMD module oriented js framework that will be used on third party sites.
With this line, framework users will configure necessary modules
<script data-main="/main.js" src="/require.js"></script>
The problem is that data-main reference is loaded asynchronously so any js logic depending on modules loaded by main.js would fail unless I can be sure that it finished loading.
I'm pretty new to requirejs so not sure what's the good practices to create a framework that will be used by other people.
How could resolve this very simple problem?
EDIT
An example to explain my point
main.js
requirejs.config({
paths: {
jquery: '//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min',
}
});
main js reference + extra code
<script data-main="/main.js" src="/require.js"></script>
<script>
require(['jquery'], function($) {
// since main.js is not loaded yet, it will assume that there is a jquery.js
// file on the same folder that this file
console.log('myModule was also loaded and can use jQuery');
});
</script>
If you want to depend on other libraries and are specifically targeting being in a Require pipeline, all you need to do is to declare some dependencies with
define(
'myModule', // module name
['foo'], // module dependencies
function(foo){ // module construction
var myModule = {};
.... code to set up the module ....
return myModule;
});
and Require will take care of things. This will register your module with Require and won't attempt to build your module until all of your dependencies are available. This functionality is discussed here.
Update with example
Require JS is designed to work both with and without a prebuilt configuration. The paths property of the Require config object only provides Require with information on how to attempt to find libraries which have not yet been registered. However, the registration and then dependency resolution is handled by Require regardless of how/where the module was registered. Please see this JSFiddle for a working example of how you can register and use dependencies.
Update 2 regarding config
Since RequireJS loads everything asynchronously, you are correct, your code example will not work. However, you're making an incorrect assumption about how it is "supposed" to work. You have an incorrect example of what your library's clients' Require configuration will look like. If someone else is building an application using RequireJS and they want to use your library, they should declare the path to your library in their require.config:
require.config({
paths: {
// this tells require how to load jQuery (a library maintained neither by you nor your clients).
'jquery': '//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min',
// this tells require how to load myModule (the library you are building for your clients).
'myModule': '//example.com/js/my-module.min',
// this tells require how to load foo (a library built and hosted by your clients).
'foo': 'scripts/foo'
}
});
On the other hand, if your clients can't update their Require config to include your library in the declarations, then you're out of luck. All you can do is take all of your dependencies and bundle them up in your distribution file and then declare no dependencies:
define(
'myModule',
[], // can't declare any dependencies
function() {
// these dependencies are inside of the definition function to keep the global namespace clean
// since we need jQuery, we have to inline it:
var jQuery = ....
// same goes for d3.js
var d3 = ....
// now we can set up the module itself
var myModule = {};
.... code to set up the module ....
return myModule;
}
);
Obviously, this option means that you can't use the libraries which are being used by your clients. This means your library will be a lot heavier and include effectively duplicate code and data.
Hope that helps you understand how Require works and how other people will use your library.
I've finally used this approach
<script src="http://mydomain/js/require.js"></script>
<script>
requirejs.config({
baseUrl: 'http://mydomain/js'
});
require(['main'],function(){
// here users can do anything they want as all required libraries are loaded
});
</script>
main.js is loaded with a require instruction instead of using data-main attribute from script tag , this provides a callback where users can put their code.

Does AngularJS support AMD like RequireJS?

In this repo AngularJS is implimented with RequireJS for AMD.
In this repo the AngularJS team seeds an AngularJS project with AMD that does not include RequireJS.
Am I thinking about this the wrong way - I.E. are they solving different problems?
Does the AngularJS libary support AMD now where it had not once before?
Is it no longer necessary to use RequireJS with AngularJS projects?
Using RequireJS with AngularJS makes sense but only if you understand how each of them works regarding dependency injection, as although both of them injects dependencies, they inject very different things.
AngularJS has its own dependency system that let you inject AngularJS modules to a newly created module in order to reuse implementations. Let's say you created a "first" module that implements an AngularJS filter "greet":
angular
.module('first', [])
.filter('greet', function() {
return function(name) {
return 'Hello, ' + name + '!';
}
});
And now let's say you want to use the "greet" filter in another module called "second" that implements a "goodbye" filter. You may do that injecting the "first" module to the "second" module:
angular
.module('second', ['first'])
.filter('goodbye', function() {
return function(name) {
return 'Good bye, ' + name + '!';
}
});
The thing is that in order to make this work correctly without RequireJS, you have to make sure that the "first" AngularJS module is loaded on the page before you create the "second" AngularJS module. Quoting documentation:
Depending on a module implies that required module needs to be loaded
before the requiring module is loaded.
In that sense, here is where RequireJS can help you as RequireJS provides a clean way to inject scripts to the page helping you organize script dependencies between each other.
Going back to the "first" and "second" AngularJS modules, here is how you can do it using RequireJS separating the modules on different files to leverage script dependencies loading:
// firstModule.js file
define(['angular'], function(angular) {
angular
.module('first', [])
.filter('greet', function() {
return function(name) {
return 'Hello, ' + name + '!';
}
});
});
// secondModule.js file
define(['angular', 'firstModule'], function(angular) {
angular
.module('second', ['first'])
.filter('goodbye', function() {
return function(name) {
return 'Good bye, ' + name + '!';
}
});
});
You can see that we are depending on "firstModule" file to be injected before the content of the RequireJS callback can be executed which needs "first" AngularJS module to be loaded to create "second" AngularJS module.
Side note: Injecting "angular" on the "firstModule" and "secondModule" files as dependency is required in order to use AngularJS inside the RequireJS callback function and it have to be configured on RequireJS config to map "angular" to the library code. You may have AngularJS loaded to the page in a traditional manner too (script tag) although defeats RequireJS benefits.
More details on having RequireJS support from AngularJS core from 2.0 version on my blog post.
Based on my blog post "Making sense of RequireJS with AngularJS", here is the link.
Yes, you can use RequireJS with angular. You need to do a bit of extra work to make it function, as in the link you included, but it's possible.
In general, though, I haven't found any need for AMD with Angular. The whole idea of AMD is that it allows you to declaratively specify the dependencies between your scripts and not worry about the order in which you include them on the page. However, Angular takes care of that for you with its dependency injection mechanism, so you're not really getting any benefit by using AMD on top of that.
tl;dr I haven't found a compelling reason to use AMD with Angular.js.
You can lazy load Angular.js components using providers. From the article:
Providers are essentially objects that are used to create and configure instances of AngularJS artefacts. Hence, in order to register a lazy controller, you would use the $controllerProvider.
...
In summary, you would first define your app module to keep instances of the relevant providers. Then you would define your lazy artefacts to register themselves using the providers rather than the module API. Then using a ‘resolve’ function that returns a promise in your route definition, you would load all lazy artefacts and resolve the promise once they have been loaded. This ensures that all lazy artefacts will be available before the relevant route is rendered. Also, don’t forget to resolve the promise inside $rootScope.$apply, if the resolution will be happening outside of AngularJS. Then you would create a ‘bootstrap’ script that first loads the app module before bootstrapping the app. Finally, you would link to the bootstrap script from your ‘index.html’ file.
http://ify.io/lazy-loading-in-angularjs/

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