AngularJS controller and service creation - angularjs

Im working on a new Angular project with the following files:
//app.js
var mainApp = angular.module('mainApp', ['serviceA', 'serviceB', "ctrlA", 'ctrlB']);
//ctrlA.js
var ctlA = angular.module('serviceA', []);
ctlA.controller('menuController', ['$scope', 'serviceA', function($scope, serviceA) {
// ...
}]);
Is there a reason not to do it this way ?
//ctrlB.js
angular.module('mainApp')
.controller('ctrlB', ['$scope', 'serviceA', function($scope, serviceA) {
// ...
}]);

What Zenorbi, mentioned is absolutely right. However, thought of adding this information to conclude a better answer.
You can modularize the app into multiple segments to make it easy to understand. The segmentation can be
done in different ways.
Based on service types - this will be useful for small applications
var mainApp = angular.module('mainApp', [
'app.controllers', // Controllers
'app.directives', // Directives
'app.filters', // Filters
'app.services' // Services
]);
Example implementation of a module.
var ctrls = angular.module('app.controllers');
ctrls.controller('menuController', ['$scope', 'serviceA', function($scope, serviceA) {
// ...
}]);
According to the purpose of each module. For example, you can separate chart related classes to a separate module and isolate it from the main code base. This will allow parallel programming by someone else, as this module can act independent from the parent module.

Both implementations are valid, but the module system is there to make sure you separate a bigger application into modules. If serviceA, serviceB, ctrlA and ctrlB are closely related, you might as well bundle them into a module. If you want to have your services elsewhere, you may create a module called mainApp.services.
It is up to you, how you structure the code, but modules exist for a reason. To have more than one "thing" in them.

Related

Bootstrap UI - $modal remains undefined

I'm reasonably new to Angular, and I'm having a weird problem when trying to use Angular Bootstrap UI.
I already know that it's being injected correctly, as the Typeahead component is working fine. I'm just starting to switch old code that calls JQuery modals within the controller into bootstrap to make them more testable, but for some reason even though I inject $modal through to the controller, it remains undefined and I cannot use it.
var MYAPP = MYAPP || {};
(function (angular) {
var common = MYAPP.common,
controllers = common.controllers,
directives = common.directives,
factories = common.factories,
filters = common.filters,
services = common.services,
repositories = common.repositories,
application = angular.module('MyModule', ['ngAnimate','ui.bootstrap']);
application.directive('positiveInteger', directives.positiveInteger);
application.filter('decimalPrecision', filters.decimalPrecisionFilter);
application.service('httpService', ['$http', repositories.httpService]);
MYAPP.application = application;
})(window.angular);
Then the module (loading in a seperate js file) :
var MYAPP = MYAPP || {},
someModule = MYAPP.namespace('someModule');
(function (application) {
/****************** Controller definitions **********************/
application.controller('myController', ['$rootScope', '$scope', '$modal', someModule.myController]);
})(MYAPP.application);
Then here's the controller code :
var MYAPP = MYAPP || {},
someModule = MYAPP.namespace('someModule');
someModule.myController = function($rootScope, $scope, $modal) {
var _controller = this;
etc etc
And then myController would be called with the above arguments, including the injected $modal. $modal is undefined within the controller.
Weirdly I can see that ui.bootstrap is in there, as inspecting the loaded modules I can see it exists, as does the other components. For example, angular.modules('ui.bootstrap') returns ok. If I mis-spell it, or enter a dummy name - it complains as I'd expect.
Interestingly the same applies if I enter a 'bad' injection annotation against the controller. For example :
application.controller('myController', ['$rootScope', '$scope', '$modalXXXYYY', someModule.myController]);
returns :
[$injector:unpr] Unknown provider: $modalXXXYYYProvider <- $modalXXXYYY <- myController
I'm not sure what's going on here - or how to diagnose it. I've checked obvious things like if it's being loaded in twice, but nothing like that seems to be going on. It's quite a large application overall, so this is heavily simplified, but any input would be much appreciated.
Thanks in advance,
Tony
Ok I've figured it out - and now I feel stupid.
Basically I wasn't persisting the passed in value in any way, so whilst $modal was passed across to the controller, the point where I was debugging (within a controller method) no longer had the variable in scope - which gave me the (false) impression that it wasn't actually passing it at all.
It was just a case of persisting the value to the controller e.g. _controller.modalService = $modal, and that sorted it out.

Splitting Module Pieces Across Multiple Files in AngularJS

I am working on an AngularJS app. I need to create a module that I can include in other projects. This module has services and directives that are spread across multiple files.
Here is my plunker
From the plunker, you can see that I'm trying to load the module like this:
var app = angular.module('app', ['my.module']);
However, I get an error that says:
Module 'my.module' is not available! You either misspelled the module name or forgot
However, I believe I am referencing it properly. Which makes me think that I'm not bundling the pieces of the module correctly. My directive an service were working fine until I tried putting them into a module. Now, its not working and I'm not sure how to get it working. I would appreciate any help I can get.
I think you had a few things confused here. You were creating the module multiple times, and you were mixing the variable name ("app") with the module name ("my.module"). Also, the plunker code doesn't match the code that you posted.
Anyway, I think this should clean it up (plunker):
var app = angular.module('my.module', []);
app.controller('AppController', ['$scope', function($scope) {
$scope.test = '';
}]);
app.service('myService', ['$timeout', '$q', function($timeout, $q) {
//[etc.
]});
app.directive('myDirective', [function() {
//etc.
}]);
Edit
Ok, I misunderstood your code.
It looks like plunkr loads scripts from bottom to top (?), so I declared the module variable in myService.js, and referenced it in myDirective.js.
New Plunker

What is the difference between these two ways of defining controllers?

Regarding controller definitions. What is the difference between this...
angular.module('myApp', ['ui.bootstrap']);
function CarouselCtrl($scope) {
...
}
and this...
var myAppModule = angular.module('myApp', ['ui.bootstrap']);
myAppModule.controller('CarouselCtrl', function($scope){
...
}
It seems that both of them get access to ui.bootstrap.
How is the first CarouselCtrl function connected to my angular.module?
The first one is a global function. You should not be using it. It is "connected" to your module because it is connected to everything.
The second one is a controller declared in a module. this is fine and it's a usual approach. You can have a module with directives, a module with services, etc. More about organizing your application
The safest option is using annotations:
var myAppModule = angular.module('myApp', ['ui.bootstrap']);
myAppModule.controller('CarouselCtrl', [ '$scope', '$http', function($scope, $http){
...
}]);
As Golo Roden points out in the comments, you can avoid global variables by referencing the controller like this:
angular.module('myApp').controller(...);
This way the application can be minified without breaking, as explained in the manual https://docs.angularjs.org/guide/di
the reason is that dependency injection looks up components by name. you can minify the name of a function but values in arrays will never be altered. The order in the array is important. it matches 1-1 with the parameters in the function.

How do I correctly split angularjs module controllers/services/etc into their own files?

I've seen some projects keep all the "pieces" (controllers/services/directives) to a module in one file. angular-app does it like that.
example:
angular.module('myModule', ['depA', 'depB'])
.controller('MyController', function() {})
.service('myService', function() {});
However I've worked on teams in the past on large angular projects where individual controllers/services/directives were kept in their own files. I like the idea of keeping them in their own files to keep the files small among other reasons. The problem now is that I'm the one in charge of getting the beginning pieces and build process put together. All I had to do before was write application code and follow the standard on those projects.
In order to have separate files properly, I believe I would have to have one main module file.
example:
// file 1
angular.module('myModule', ['depA', 'depB']);
// file 2
angular.module('myModule')
.controller('MyController', function() {});
So my question is, what file loading order do I need to make sure happens? Do I only need to make sure that the main module file (file 1) is loaded before file 2?
That seems odd to me. If there was also a service file attached to the previously mentioned module and the controller file 2 was already loaded, but the service file wasn't yet, isn't it possible that angular could invoke that controller file and then eventually cause things to get out of whack?
Also, if you think I'm handling this the wrong way I would love to hear your suggestions.
Module Load Order
Just make sure that when you register a new module, by the time your application bootstraps, it's module dependencies should have already been loaded by the browser.
So anytime you do this:
angular.module('myApp', ['dep1', 'dep2', 'dep3']);
The files with dep1, dep2, and dep3 should have already been loaded by the time your application bootstraps.
If you are using <script> tags and automatic bootstrapping (the angular default) then the order of your <script> tags shouldn't matter. However, if using a library like requirejs make sure that all of your dependencies are loaded before manually bootstrapping.
Additional Considerations
As long as your modules are loaded in the correct order, then..
There is no need to worry about the order of controllers, directives, services, factories, providers, constants, or values
The order of run blocks may be important only as they relate to other run blocks since they are executed in the order in which they are registered (within a specific module).
The order of config blocks may be important only as they relate to other config blocks since they are executed in the order in which they are registered (within a specific module).
In regards to the prior 2 points, the order of dependencies (for example ['dep1', 'dep2', 'dep3'] vs ['dep2', 'dep3', 'dep1']) will also effect the order of execution of run blocks and config blocks. Angular will traverse the dependency tree twice and execute, in order, all config blocks followed by all run blocks.
Angular uses a post-order traversal to initialize modules and their associated config and run blocks. So if we represent our module dependencies as a tree:
The order of traversal is ACEDBHIGF
What I do on my projects, is keep everything separate in the developing environment, but then compile things down via gulp.js (grunt should work as well). That's a separate subject though, but here's an example of how to keep your angular code in different files.
The main file (must be loaded first) could be as follows. We will define our module, controllers, directives, repositories, or whatever else. Let's call it app.js:
// AngularJS Application File
var example = angular.module(
// ngApp name
'example',
// Default Dependencies
[
'exampleControllers',
'exampleRepositories',
'exampleDirectives'
]
);
var exampleControllers = angular.module('exampleControllers', []);
var exampleRepositories = angular.module('exampleRepositories', []);
var exampleDirectives = angular.module('exampleDirectives', []);
Now, we can access this exampleControllers, exampleRepositories, and exampleDirectives from within any javascript file that follows.
controllers.js file.
exampleControllers
// Main Controller
.controller('MainController',
[
'$scope',
'$log',
function ($scope, $log) {
$scope.hello = 'Hello World';
}
]
)
// Sub Page Controller
.controller('SubPageController',
[
'$scope',
'someService',
'$log',
function ($scope, sService, $log) {
$log.info($scope.hello);
}
]
);
anothercontroller.js file:
exampleControllers
// Another Controller
.controller('AnotherController',
[
'$scope',
'$log',
function ($scope, $log) {
$scope.helloagain = 'Hello World, from another controller';
}
]
)
And so forth.. Just make sure your app.js file gets loaded first so the example<whatever> variables are available.
I would definitely read up on gulp.js (http://gulpjs.com/). It's pretty awesome for automating work flows.

AngularJS best practices for module declaration?

I have a bunch of Angular modules declared in my app. I originally started declaring them using the "chained" syntax like this:
angular.module('mymodule', [])
.controller('myctrl', ['dep1', function(dep1){ ... }])
.service('myservice', ['dep2', function(dep2){ ... }])
... // more here
But I decided that wasn't very easy to read, so I started declaring them using a module variable like this:
var mod = angular.module('mymodule', []);
mod.controller('myctrl', ['dep1', function(dep1){ ... }]);
mod.service('myservice', ['dep2', function(dep2){ ... }]);
...
The second syntax seems a lot more readable to me, but my only complaint is that this syntax leaves the mod variable out in the global scope. If I ever have some other variable named mod, it would be overridden with this next one (and other issues associated with global variables).
So my question is, is this the best way? Or would it be better to do something like this?:
(function(){
var mod = angular.module('mymod', []);
mod.controller('myctrl', ['dep1', function(dep1){ ... }]);
mod.service('myservice', ['dep2', function(dep2){ ... }]);
...
})();
Or does it even matter enough to care? Just curious to know what the "best practices" are for module declaration.
'Best' way to declare a module
As angular is on the global scope itself and modules are saved to its variable you can access modules via angular.module('mymod'):
// one file
// NOTE: the immediately invoked function expression
// is used to exemplify different files and is not required
(function(){
// declaring the module in one file / anonymous function
// (only pass a second parameter THIS ONE TIME as a redecleration creates bugs
// which are very hard to dedect)
angular.module('mymod', []);
})();
// another file and/or another anonymous function
(function(){
// using the function form of use-strict...
"use strict";
// accessing the module in another.
// this can be done by calling angular.module without the []-brackets
angular.module('mymod')
.controller('myctrl', ['dep1', function(dep1){
//..
}])
// appending another service/controller/filter etc to the same module-call inside the same file
.service('myservice', ['dep2', function(dep2){
//...
}]);
// you can of course use angular.module('mymod') here as well
angular.module('mymod').controller('anothermyctrl', ['dep1', function(dep1){
//..
}])
})();
No other global variables are required.
Of course it depends all on preferences, but I think this is kind of the best practise, as
you don't have to pollute the global scope
you can access your modules everywhere and sort them and their functions into different files at will
you can use the function-form of "use strict";
the loading order of files does not matter as much
Options for sorting your modules and files
This way of declaring and accessing modules makes you very flexible. You can sort modules via function-type (like described in another answer) or via route, e.g.:
/******** sorting by route **********/
angular.module('home')...
angular.module('another-route')...
angular.module('shared')...
How you sort it in the end is a matter of personal taste and the scale and type of the project. I personally like to group all files of a module inside of the same folder (ordered into sub-folders of directives, controllers, services and filters), including all different test-files, as it makes your modules more reusable. Thus in middle-sized projects I end up with a base-module, which includes all basic routes and their controllers, services, directives and more or less complex sub-modules, when I think they could be useful for other projects as well,e.g.:
/******** modularizing feature-sets **********/
/controllers
/directives
/filters
/services
/my-map-sub-module
/my-map-sub-module/controllers
/my-map-sub-module/services
app.js
...
angular.module('app', [
'app.directives',
'app.filters',
'app.controllers',
'app.services',
'myMapSubModule'
]);
angular.module('myMapSubModule',[
'myMapSubModule.controllers',
'myMapSubModule.services',
// only if they are specific to the module
'myMapSubModule.directives',
'myMapSubModule.filters'
]);
For very big projects, I sometimes end up grouping modules by routes, as described above or by some selected main routes or a even a combination of routes and some selected components, but it really depends.
EDIT:
Just because it is related and I ran into that very recently again: Take good care that you create a module only once (by adding a second parameter to the angular.module-function). This will mess up your application and can be very hard to detect.
2015 EDIT on sorting modules:
One and a half year of angular-experience later, I can add that the benefits from using differently named modules within your app are somewhat limited as AMD still does not really work well with Angular and services, directives and filters are globally available inside the angular context anyway (as exemplified here). There is still a semantic and structural benefit though and it might be helpful being able to include/ exclude a module with a single line of code commented in or out.
It also almost never makes much sense to separate sub-modules by type (eg. 'myMapSubModule.controllers') as they usually depend on each other.
I love the angular-styleguide by Johnpapa, and here are some rules that related to this question:
Rule: Named vs Anonymous Functions
Avoid using anonymous functions:
// dashboard.js
angular
.module('app')
.controller('Dashboard', function() { })
Instead, use named functions:
// dashboard.js
angular
.module('app')
.controller('Dashboard', Dashboard);
function Dashboard() { }
As the author says: This produces more readable code, is much easier to debug, and reduces the amount of nested callback code.
Rule : Define 1 component per file.
Avoid multiple components in one file:
angular
.module('app', ['ngRoute'])
.controller('SomeController', SomeController)
.factory('someFactory', someFactory);
function SomeController() { }
function someFactory() { }
Intead, use one file to define the module:
// app.module.js
angular
.module('app', ['ngRoute']);
one file just uses the module to define a component
// someController.js
angular
.module('app')
.controller('SomeController', SomeController);
function SomeController() { }
and another file to define another component
// someFactory.js
angular
.module('app')
.factory('someFactory', someFactory);
function someFactory() { }
Of course, there are many other rules for modules, controllers and services that are quite useful and worth reading.
And thanks to comment of ya_dimon, the above code should be wrapped in IIFE, for example:
(function (window, angular) {
angular.module('app')
.controller('Dashboard', function () { });
})(window, window.angular);
I recently had this conundrum as well. I had started off just like you using the chained syntax, but in the long run it becomes unwieldy with large projects. Normally I'd create a controllers module, a services module and so on in separate files and inject them into my main application module found in another file. For Example:
// My Controllers File
angular.module('my-controllers',[])
.controller('oneCtrl',[...])
.controller('twoCtrl',[...]);
// My Services File
angular.module('my-services',[])
.factory('oneSrc',[...])
.facotry('twoSrc',[...]);
// My Directives File
angular.module('my-directives',[])
.directive('oneDrct',[...])
.directive('twoDrct',[...]);
// My Main Application File
angular.module('my-app',['my-controllers','my-services','my-directives',...]);
But each one of these files was getting way to large as the project grew. So I decided to break them up into separate files based on each controller or service. I found that using angular.module('mod-name'). without the injection array, is what you need for this to work. Declaring a global variable in one file and expecting that to be readily available in another just doesn't work or could have unexpected results.
So in short my application looked something like this:
// Main Controller File
angular.module('my-controllers',[]);
// Controller One File
angular.module('my-controllers').controller('oneCtrl',[...]);
//Controller Two File
angular.module('my-controllers').controller('twoCtrl',[...]);
I did this to the services file as well, no need to change the main application module file you'd still be injecting the same modules into that.
One other practice is to stuff controllers, directives, etc in their own modules and inject those modules into your "main" one:
angular.module('app.controllers', [])
.controller('controller1', ['$scope', function (scope) {
scope.name = "USER!";
}]);
angular.module('app.directives', [])
.directive('myDirective', [function () {
return {
restrict: 'A',
template: '<div>my directive!</div>'
}
}]);
angular.module('app', [
'app.controllers',
'app.directives'
]);
Nothing is left in the global scope.
http://plnkr.co/edit/EtzzPRyxWT1MkhK7KcLo?p=preview
I like to divide my files and my modules.
Something like this:
app.js
var myApp = angular.module('myApp', ['myApp.controllers', 'myApp.directives', 'myApp.services']);
myApp.config(['$routeProvider', function($routeProvider) {
/* routes configs */
$routeProvider.when(/*...*/);
}]);
directives.js
var myDirectives = angular.module('myApp.directives', []);
myDirectives.directive( /* ... */ );
service.js
var myServices = angular.module('myApp.services', []);
myServices.factory( /* ... */ );
Im not a big fan of the "chained style", so I prefer to write down my variable always.
I suggest to follow Angularjs Style Guide.
They handle all concept from naming convention, to modularize your app and so on.
For angular 2, you can check Angular 2 Style Guide
For me, chaining is the most compact way:
angular.module("mod1",["mod1.submod1"])
.value("myValues", {
...
})
.factory("myFactory", function(myValues){
...
})
.controller("MainCtrl", function($scope){
// when using "Ctrl as" syntax
var MC = this;
MC.data = ...;
})
;
That way I can easily move components between modules, never need to declare the same module twice, never need any global variables.
And if the file gets too long, solution is simple - split into two files, each declaring its own module at the top. For more transparency, I try to keep one unique module per file and name it resembling the full path of the file. This way also I never need to write a module without [], which is a common pain point.

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