Is the angular ngRoute 'Controller' declaration necessary? - angularjs

After reading both the api and the developer guide, I still don't understand the functionality provided by declaring 'controller' in a given route. Right now I just have my controllers declared as ng-controller directives in my views. Is ngRoute simply providing an alternative method?
To make my question explicit in code, see below:
--Index.html
...
<body ng-app="MyApp">
<div ng-view>
</div>
</body>
--View.html
<div id="myView" ng-controller="MyController">
...
</div>
--Route.js
var app = angular.module('MyApp', [ require('angular-route') ]);
app.controller('MyController', ['$scope', function ($scope) {
console.log('this gets executed as I would expect');
}])
.config(['$routeProvider', function($routeProvider) {
$routeProvider.when('/', { templateUrl: '/Index.html' })
.when('/view', { templateUrl: '/View.html' });
// below line makes no difference as an alternative to above
//.when('/view', { templateUrl: '/View.html', controller: 'MyController' });
}]);

There are two ways to define controller for a view.
Either in the controller declaration in the ng-route
in the ng-controller for the view.
Either one is fine.

You should pick one option over the other since using both will actually give you duplicate controllers, i.e. both will be used. If you're using Routes, then you can specify a few additional properties such as resolve which has been mentioned in the comments and this will allow you to perform an action, or supply supplementary data etc.
Take a look at this article, Using Resolve In Angular, for more information.
Also, you should look into using Controller As, which sets you up for future proofing. John Papa has a few blogs and videos where he praises the use of Controller As and using the var vm = this; style syntax, take a look here.
Also, as a side note, you should use the .otherwise in your routes as this will capture any requests that are invalid and at least serve up a valid page from your site. You can see this in the routeProvider documentation.

Related

Is it acceptable to load controllers in the route AND body?

Most articles demonstrate one method or the other... specifying the controller in the route OR the body. While I realize specifying the controller in the route provides additional benefits WHEN NEEDED (pre-loading required view resources, etc.), it is illogical to think that a modular application will be able to (or SHOULD) handle all of the functionality for a complex view.
Any proven examples (links) showing a combined approach would really help ease my mind.
Thanks, in advance.
No.
You may use both, but not for the same instance of a controller.
As an example, you can use ng-controller for your page menu controller and define the page controller loaded into your ui-view in the state config. This is fine as long as the page view does not have an ng-controller the same controller.
Your controllers constructor will run twice if you invoke it twice.
Added Snippet to Demonstrate
So in the following code we bring in the controller IndexCtrl in the uiRouter state config and in the index.html view. As you can see if you run this snippet, you have two instances of the IndexCtrl running.
Why is this a problem?
It is not a problem if this is your intention. It becomes a problem if this is your intention, to have two instances of the controller. If you follow this pattern unknowingly and create an application you will have an unneeded instance of every controller.
This will also cause developer confusion. How come I can't get back the value of a property in a controller? You will see bugs like this because a developer will set a property on one instance of a controller and then expect the same value to be in the other instance.
Controllers are classes. They are constructor functions -- so you can have multiple instances of them. And there are valid use cases to have multiple instances of a controller. But you shouldn't accidentally have two instances.
angular.module('app', ['ui.router'])
.config(['$stateProvider',
function($stateProvider) {
$stateProvider.state('index', {
url: '*path',
controller: "IndexCtrl as vm1",
templateUrl: 'index.html'
});
}
])
.controller('IndexCtrl', IndexCtrl);
function IndexCtrl() {
this.value = 0;
}
IndexCtrl.prototype.add = function() {
this.value += 1;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="http://angular-ui.github.io/ui-router/release/angular-ui-router.min.js"></script>
<div ng-app="app">
<ui-view></ui-view>
<script type="text/ng-template" id="index.html">
<div ng-controller="IndexCtrl as vm2">
Controller1 {{vm1.value}} Controller2 {{vm2.value}}
<button ng-click="vm1.add()">Add Ctrl1</button>
<button ng-click="vm2.add()">Add Ctrl2</button>
</div>
</script>
</div>

How angular controllers bind with view?

I dont understand how controllers is connecting with views in Hawtio project.
for example, view:
<div ng-controller="Core.AboutController">
<div class="welcome">
<div class="about-display" compile="html"></div>
</div>
</div>
controller declaration:
module Core {
export function AboutController($scope, $location, jolokia, branding, localStorage) {
//...
}
//...
}
I expected to find something like that:
angular.module('moduleName').controller('Core.AboutController', Core.AboutController);
But found none. How it works?
This works because in the absence of any registration with angular i.e. angular.module('moduleName').controller('Core.AboutController' angular looks at window and tries to resolve it. Which is what
module Core {
export function AboutController
does. After this line window.Core.AboutController will point to the correct function and that is what angular just found.
just look at the attribute in the first line of the HTML sample you posted.
ng-controller="Core.AboutController"
There are (As far as I know) two ways of associating a view to a controller. The first is with a an attribute, like in this example. The second is while configuring the router:
angular.module('MyApp', ['Core.Aboutcontrollers']).
config(['$routeProvider', function($routeProvider) {
$routeProvider.when('/path', {templateUrl: 'partials/myfile.html' });
}]);
Don't do both of them, or your controller will be invoked twice.

Angular $routeParams is blank

I have a really simple Angular app that I've distilled to the following:
var napp = angular.module('Napp',['ngResource']);
var CompanyCtrl = function($scope, $routeParams, $location, $resource) {
console.log($routeParams);
};
napp.config(['$routeProvider', function($routeProvider) {
$routeProvider
.when('/company/edit/:id',
{templateUrl: '/partials/edit', controller: 'CompanyCtrl'}
);
}]);
and the HTML:
<div ng-controller="CompanyCtrl"></div>
When I log $routeParams, it comes up blank. When I use .otherwise(), it will load whatever I've specified there. Any idea what I'm missing?
You have a couple of errors:
You've specified the controller in two places, both in the view (<div ng-controller="CompanyCtrl"></div>) and in $routeProvider (.when('/company/edit/:id', {templateUrl: '/partials/edit', controller: 'CompanyCtrl'}). I'd remove the one in the view.
You have to register the controller in the module when specifying it in the $routeProvider (you should really do this anyway, it's better to avoid global controllers). Do napp.controller('CompanyCtrl', function ... instead of var CompanyCtrl = function ....
You need to specify a ng-view when you're using the $route service (not sure if you're doing this or not)
The new code:
var napp = angular.module('Napp', ['ngResource']);
napp.controller('CompanyCtrl', function ($scope, $routeParams, $location, $resource) {
console.log($routeParams);
});
napp.config(['$routeProvider', function ($routeProvider) {
$routeProvider
.when('/company/edit/:id',
{templateUrl: '/partials/edit', controller: 'CompanyCtrl'}
);
}]);
The template (/parials/edit)
<div> ... </div>
And the app (index.html or something)
... <body> <div ng-view></div> </body>
I've created a working plunker example: http://plnkr.co/edit/PQXke2d1IEJfh2BKNE23?p=preview
First of all try this with
$locationProvider.html5Mode(true);
That should fix your starting code. Then adjust your code to support non-pushState browsers.
Hope this helps!
Not sure if this helps, but I just came across this issue myself, and found that I couldn't log the route params until I had something bound to them.
So,
Router:
var myApp = angular.module('myApp', []);
myApp.config(function($routeProvider){
$routeProvider.when('/projects/:id',
{templateUrl: '/views/projects/show.html', controller: 'ProjectCtrl'}
);
});
Controller:
myApp.controller('ProjectCtrl', function($scope, $routeParams){
$scope.id = $routeParams.id;
console.log('test');
});
View:
<h1>{{ id }}</h1>
When I removed the '{{id}}' from the view, nothing was logged and $routeParams was empty, at least at the time of the controller's instantiation. As some of the answers above have pointed to, the route params are passed in asynchronously, so a controller with no bindings to that property won't execute. So, not sure exactly what you've distilled your snippet down from, but hope this helps!
This may happen (not in the OP's case) if you're using ui-router instead of ngRoute.
If that's the case, use $stateParams instead of $routeParams.
https://stackoverflow.com/a/26946824/995229
Of course it will be blank. RouteParams is loaded asynchronously so you need to wait for it to get the params. Put this in your controller:
$scope.$on('$routeChangeSuccess', function() {
console.log($routeParams);
});
It works for me http://plunker.co/edit/ziLG1cZg8D8cYoiDcWRg?p=preview
But you have some errors in your code:
Your don't seem to have a ngView in your code. The $routeProvider uses the ngView to know where it should insert the template's content. So you need it somewhere in your page.
You're specifying your CompanyCtrl in two places. You should specify it either in the $routeProvider, or in you template using ng-controller. I like specifying it in the template, but that's just personal preference.
Although not an error, you're specifying your CompanyCtrl in the global scope, instead of registering it on your Napp module using Napp.controller(name, fn).
Hope this helps!
You can always go on #angularjs irc channel on freenode: there's always active people ready to help
Could it be that your templateUrl points to an invalid template?
When you change the templateUrl to an unexisting file, you will notice that the $routeParams will no longer be populated (because AngularJS detects an error when resolving the template).
I have created a working plnkr with your code for your convenience that you can just copy and paste to get your application working:
http://plnkr.co/edit/Yabp4c9zmDGQsUOa2epZ?p=preview
As soon as you click the link in the example, you will see the router in action.
Hope that helps!

How to load language-specific templates in AngularJS?

I have a route defined as
$routeProvider.when('/:culture/:gameKey/:gameId/closed', { templateUrl: '/templates/tradingclosed', controller: TradingClosedCtrl });
I would like angular to include the "culture" parameter when requesting the template somehow, so I can serve a translated template.
Is this possible?
If I'm reading this correctly you'd like to somehow use the culture parameter from the url route to determine which location to retrieve your template.
There may be a better way but this post describes retrieving the $routeParams inside a centralized controller with ng-include to dynamically load a view.
Something similar to this:
angular.module('myApp', []).
config(function ($routeProvider) {
$routeProvider.when('/:culture/:gameKey/:gameId/closed', {
templateUrl: '/templates/nav/urlRouter.html',
controller: 'RouteController'
});
});
function RouteController($scope, $routeParams) {
$scope.templateUrl = 'templates/tradingclosed/' + $routeParams.culture + '_template.html';
}
With this as your urlRouter.html:
<div ng-include src="templateUrl"></div>
You can define the controller you want to load in your views using ng-controller and access the $routeParams for the additional route parameters:
<div ng-controller="TradingClosedCtrl">
</div>
I've posted similar question with working Plnkr example of solution like #Gloopy suggested.
The reason why you can't implement that without ng-include is that routing is done in 'configuration' block, where you can't inject any values (you can read about these blocks in Modules documentation, section Module Loading & Dependencies
If you want not to introduce new scope, you can replace ng-include with my stripped version of ng-include directive, that do absolutely same that ng-include does, but do not create new scope: source of rawInclude directive
Hope that solution will satisfy your use case.

How to include one partial into other without creating a new scope?

I've this routes.
// index.html
<div ng-controller="mainCtrl">
<a href='#/one'>One</a>
<a href='#/two'>Two</a>
</div>​​​​​​​​​
<div ng-view></div>
And this is how I'm loading the partials into my ng-view.
// app.js
​var App = angular.module('app', []);​​​​​​​
App.config(['$routeProvider', function($routeProvider) {
$routeProvider.when('/one', {template: 'partials/one.html', controller: App.oneCtrl});
$routeProvider.when('/two', {template: 'partials/two.html', controller: App.twoCtrl});
}]);
When I click the links, it shows me the appropriate markup inside the ng-view. But when I try to include partials/two.html inside partials/one.html using ng-include, it shows it properly but creates a different scope so I'm not able to interact with it.
// partials/two.html - markup
<div ng-controller="twoCtrl">I'm a heading of Two</div>
// partials/one.html - markup
<div ng-controller="oneCtrl">I'm a heading of One</div>
<div ng-include src="'partials/two.html'"></div>
​
How do I resolve this problem? Or Is there any other way to achieve the same result?
You can write your own include directive that does not create a new scope. For example:
MyDirectives.directive('staticInclude', function($http, $templateCache, $compile) {
return function(scope, element, attrs) {
var templatePath = attrs.staticInclude;
$http.get(templatePath, { cache: $templateCache }).success(function(response) {
var contents = element.html(response).contents();
$compile(contents)(scope);
});
};
});
You can use this like:
<div static-include="my/file.html"></div>
The documentation for ngInclude states "This directive creates new scope." so this is by design.
Depending on the type of interaction you are looking for you may want to take a look at this post for one way to share data/functionality between the two controllers via a custom service.
So this isn't an answer to this question but i made it here looking for something similar and hopefully this will help others.
This directive will include a partial without creating a new scope. For an example you can create a form in the partial and control that form from the parent controller.
Here is a link to the Repo that i created for it.
good luck :-)
-James Harrington
You can actually do this without using a shared service. $scope.$emit(...) can dispatch events to the $rootScope, which can listen for them and rebroadcast to the child scopes.
Demo: http://jsfiddle.net/VxafF/
Reference:
http://www.youtube.com/watch?v=1OALSkJGsRw (see the first comment)

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