in my app I have a wrapper controller that handles some properties dynamically based on other-controllers within it. everything works like a charm if the other-controllers are present/static on load, but as soon as I'm trying to make them dynamic, they stop working.
It was my understanding that the $rootScope is available from everywhere within the app, is that not true?
my JS looks like this:
var webApp = angular.module("webApp",[]);
webApp.controller("ControllerA", function($scope, $rootScope){
$rootScope.cnt = 0;
$rootScope.cntPlusPlus = function(){
$rootScope.cnt++;
};
$rootScope.controllerBs = [];
var template = $(".controller-b").html();
$scope.addControllerB = function(){
$rootScope.controllerBs.push(template);
};
});
webApp.controller("ControllerB", function($scope, $rootScope){
$scope.cntPlusPlus = function(){
console.log("overwrite plus plus");
}
});
Full example: http://plnkr.co/edit/tAcv1F9y7t9q9XsQ1EFL?p=preview
I know that this would be probably better with directives, but is there any way to make it work with Controllers?
thanks for the help
Don't try to access the DOM from controller code. Never. It is very bad practice which breaks AngularJS conventions and eventually provides you with bad architecture. This also means you should not create any DOM elements manually from a controller.
Better to manipulate with the scope itself, not with its visual representation. You can add new models to scope on your button's click, which will be translated to new elements by ng-repeat directive, each with its own controller (remember controllers are instances, not singletons, so that they have separated life cycles).
You might want to make use of <script type="text/ng-template"> and ng-include here instead of hidden divs.
Try to avoid using $rootScope when possible - it is global state which can be dangerous.
It might look like this then (plunker):
HTML:
<div class="controller-a" ng-controller="ControllerA">
Controller A
<div>
<button ng-click="cntPlusPlus()">cnt++</button> CNT: {{cnt}}
</div>
<button ng-click="addB()">Add B</button>
<div ng-repeat="B in Bs">
<div ng-include="'b-template'"></div>
</div>
</div>
<script type="text/ng-template" id="b-template">
<div ng-controller="ControllerB">this is controller b: <button ng-click="cntPlusPlus()">cnt++</button></div>
</script>
JS:
var webApp = angular.module("webApp",[]);
webApp.controller("ControllerA", function($scope){
$scope.cnt = 0;
$scope.cntPlusPlus = function(){
$scope.cnt++;
};
$scope.Bs = [];
$scope.addB = function(){
$scope.Bs.push({});
};
});
webApp.controller("ControllerB", function($scope){
$scope.cntPlusPlus = function(){
console.log("overwrite plus plus");
$scope.$parent.$parent.$parent.cnt++; //should be moved to service
}
});
</script>
Related
I want to update the scope inside a directive that is outside of my main view, here's my code:
index.html
<!-- the directive I want to update -->
<nav sitepicker></nav>
<section id="content-wrapper">
<!-- main content-->
<div ui-view></div>
</section>
sitepicker is essentialy just a dropdown menu that contains some html structure.
sitepicker.html
<span>{{currentWebsite}}</span> <-- this is the one I want to update
<ul>
<li ng-repeat="website in websites">{{website.name}}</li>
</ul>
and the JS:
.controller('sitepicker', function($scope, websiteService)
$scope.website = websiteService.currentWebsite; // not updating eventhough I update this in overview.js
});
overview.js
.controller('OverviewCtrl', function($scope, websiteService) {
websiteService.currentWebsite = website; // assume that this value is dynamic
});
but currentWebsite is not changing. How can I work around this? I want to avoid using $rootScope because I know it's bad.
Here's my service:
.factory('websiteService', function() {
var currentWebsite;
return {
currentWebsite: currentWebsite
};
});
Edit: Adding a watch like this works but i'm not sure if its good
.controller('sitepicker', function($scope, websiteService)
$scope.$watch(function() {
$scope.website = websiteService.currentWebsite;
});
});
Solution #1
We can add $watch to makes this possible
.controller('sitepicker', function($scope, websiteService)
$scope.$watch(function(){
return websiteService.currentWebsite;
}, function(newValue){
// Do something with the new value
});
});
Solution #2
We can also define websites in our main controller. Then, we can update it in our overview child controller like so:
.controller('sitepicker', function($scope, websiteService)
$scope.$parent.website = websiteService.currentWebsite;
});
it is important to use $parent
Since we update the controller that wraps up the whole app, we will be able to access it from anywhere, any directive, controller, view, etc.
In my mine file I have the div with ng-view and it is loaded with the some template. Inside the temp`late I have a button which will change the value.
after to click the button, I am trying to show the value in the index but I recieving a null value.
In index.html I could have something like:
<html>
...
<body ng-app="productsApp" ng-Controller="mycontroller">
<div ng-view></div>
{{value}}
</body>
</html>
In my controller I have something like
angular.module('productsApp').controller('ProductController',
['$scope', 'dataService', function ($scope, dataService) {
$scope.value;
$scope.button = function () {
$scope.value= "123";
};
}]);
The template could be something like:
<button ng-click="button">CHANGE</button>
How can I assign values to main page from templates and show them?
You need to beware which controller you set, the names have to match. Also beware of typos, even when typing fast ;). Also look into the function call. You forgot to use () at the end. And naming things a little bit better would be recommended to (I don't say my namings are the best, but calling a function button is not very readable).
HTML
<body ng-controller="MainCtrl">
<p>Value {{value}}!</p>
<button ng-click="btnPressed()">Change</button>
</body>
JS
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope) {
$scope.value = "456";
$scope.btnPressed = function() {
$scope.value = 123;
}
});
The controllers name in this example is MainCtrl. You need to refer the correct name as well in your HTML (you mix mycontroller and ProductController).
Working Plnkr
http://plnkr.co/edit/tpl:8rFfZljYNl3z1A4LKSL2
You have defined $scope.button in ProductController which set $scope.value.
But this $scope.value is come under scope of ProductController and not available under scope of mycontroller which parent scope.Thats why you getting null value.
Define $scope.value and $scope.button in mycontroller.
Or better way is define this functionality in some factory and access it wherever needed.
Or define that function and variable in $rootScope like
$rootScope.value;
but it make this global.
or define like this
$scope.$parent.value;
I have controller is named "UserController" in top of page:
<div ng-controller="UserController"><input type="text" ng-model="search"></div>
Also the same controller in bottom page from directive ng-view:
<div class="bottom" ng-controller="UserController">{{search}}</div>
Why I dont get value {{search}} in bottom part, when I fill field input in top?
Can I use one controller two times in a page?
Yes, you can use two controllers in AngularJs, Here is a demo.
What happens when I use ng-controller?
When you add ng-controller to a DOM element, angular create an instance of controller function and attaches it with that DOM, and thats why there is no two way data-binding between those divs.
How can I use data binding to share data between controllers?
You can use $rootScope variable or you can use services.
you can create service and inject in controller as dependency, so you can access its property with two way binding feature.
As said by JB Nizet, you need to have everything in the same "div".
<div ng-controller="UserController">
<input type="text" ng-model="search">
<div id="search-query">{{search}}</div>
</div>
Having the search-query at the bottom of the page is a matter of CSS, not Angular.
Controllers are not singletons. You have one controller for the top div, a second controller for the second div. One scope for the top div, one scope for the bottom div.
Both controllers have the same name, but you are ultimatally calling you controller function twice.
Some options you might want to consider to solve your problem:
Option 1) Use parent scope.
ng-model="$parent.search"
{{$parent.search}}
Option 2) Use root scope.
ng-model="$root.search"
{{$root.search}}
Option 3) Store the value in a service.
Services are singletons. If you type myService.search = $scope.search, then that value can read from the other controller.
You wont be able to watch a service variable, so perhaps you want to use the observer pattern here.
app.service("search", function() {
var listerners = [];
this.register = function(listener) {
listerners.push(listener);
};
this.update = function(searchValue) {
for(var i in listerners) {
listerners[i](searchValue);
}
};
});
app.controller("UserController", function($timeout, search){
search.register(function(searchValue) {
$timeout(function(){
$scope.search = searchValue;
});
});
$scope.$watch('search', function (newVal, oldVal, scope) {
search.update(newVal);
});
});
Option 4) Broadcast the new value.
$scope.$watch('search', function (newVal, oldVal, scope) {
$rootScope.$broadcast('search', newVal);
});
$scope.$on('search', function(event, data) {
$scope.search = data;
});
You can have multiple instances of the same controller in your page. They share the same functionality. But every instance of that controller is getting his own $scope. So in your first controller $scope.search can be 'mySearch', but the second controller won't get this, because it's another $scope.
You can do two things:
You can put the controller on a containing element, let's say the body, so both your input and your div are within the same $scope.
OR, if you want them to be seperate, you can use a service to share the search.
Your HTML:
<div ng-app="myApp">
<div ng-controller="UserController">
<input type="text" ng-model="search.mySearch"/>
</div>
<div ng-controller="UserController">
{{search.mySearch}}
</div>
</div>
Your Javascript:
var myApp = angular.module('myApp', []);
myApp.factory('Data', function(){
return { mySearch: '' };
});
myApp.controller('UserController', function( $scope, Data ){
$scope.search = Data;
});
See Fiddle
I am trying to understand Angularjs behaviors.
I am building a web-app, and I want the CurrentUser's info be shared among all the app components. To do that, I have created a CurrentUserController bound to $rootScope. This controller is used by a user directive utilized in the body html element, so that it is globally accessible and it's created just one time.
app.controller('CurrentUserController', function ($rootScope)
{
// initialization
$rootScope.userCtrl = self; //<- MAKE IT GLOBAL
this.islogged=false;
this.name="";
var self = this;
// functions
this.isLogged = function()
{ return self.islogged; };
this.setLoggedIn = function(credentials)
{ self.islogged = true; };
this.setLoggedOut = function()
{ self.islogged = false; };
}
);
app.directive('currentUser', function() {
return {
controller:'CurrentUserController'
};
})
and then my html page
<html>
...
<body current-user>
...
</body>
</html>
However I read that Services should be used to share data between controllers, since they are singleton.
So my question is:
is my approach wrong, or it is equivalent as I utilized services?
Moreover, right now I can utilize the directive ng-switch calling $rootScope.userCtrl functions, like this:
<div id="nav-right-side" class="navbar-right" ng-switch on="userCtrl.isLogged()">
<div ng-switch-when="false">
<login-button></login-button>
</div>
<div ng-switch-when="true">
<loggedin-button></loggedin-button>
</div>
</div>
If I utilize services, would I still be able to do that?
Thank you
The $rootScope is indeed shared across all the app and it is also best to store models into services.
Why bother with services ?
Because of the $digest cycle. Each time a watched value is modified, the digest is triggered. In angular, by default the digest is a loop that goes down all your scope from the $rootScope down to its leafs. On each element, it has to get if the value has been modified or not to update the view accordingly. This is pretty expensive, and it is the cause of why angular can be slow on big applications. Keeping the scope as light as possible is how you can build complex apps in angular. That's why storing things is always better in services, you do not pollute the scope with data you could put somewhere else.
That being said, auth is peculiar because you want to access the same data from the view and services. You can store it in the $rootScope as Asta puts it but I do not think that is consistant with best practices. This is opinionated
What can be done is creating a service that will hold you model and share it through a controller to have access to it from both the view and the other services/models.
Session.js
function Session(){
var
self = this,
_islogged=false,
_name = '';
// functions
this.isLogged = function() {
return self.islogged;
};
this.setLoggedIn = function() {
self.islogged = true;
};
this.setLoggedOut = function() {
self.islogged = false; };
}
// GetUsername, setUsername ... Whatever you need
}
angular
.module('app')
.service('Session', Session);
rootController.js
function rootController(Session){
// share the Session Service with the $scope
// this.session is like $scope.session when using the controllerAS syntax.
this.session = Session;
}
angular
.module('app')
.controller('rootController', rootController);
I would suggest you take a look at these articles:
Techniques for Authentification in AngularJs Applications
Comprehensive 10 000 words tutorial in angular
Diving into controllerAs syntax
Your best to use a Service to share data as you mention. In your approach you've used a Controller in a way that its not really intended.
You can call your controller from your HTML by using ng-controller so something like the following should work. This would be useful for a Login view for example or a logout directive.
<div ng-controller="userCtrl">
<div id="nav-right-side" class="navbar-right" ng-switch on="isLogged()">
<div ng-switch-when="false">
<login-button></login-button>
</div>
<div ng-switch-when="true">
<loggedin-button></loggedin-button>
</div>
</div>
</div>
In order to have your session available globally for use elsewhere you can use a service which you can initialise from your app. The session data can be added to $rootScope which you can then reference from any view or controller.
Service
angular.module('app').service('session', function($rootScope) {
$rootScope.sessionData.loggedIn = true
// extra logic etc..
});
Main App
angular.run(session)
angular.module('app').run(function(session) {});
Then to reference the variable from your view
<div id="nav-right-side" class="navbar-right" ng-switch on="sessionData.isLoggedIn">
Note: its good practice to use an object with scope variables to help avoid issues with inheritance.
I want to have element where i can have 2 views using their own controller but only one at a time.
I can't use a ng-view and use the routeProvider because in the future I need to include more ng-includes that need to change their content depending on the possible actions.
I created a fiddle http://jsfiddle.net/EvHyT/29/.
So I used a ng-include and then I set the src for it from a main controller. At that point I want to use controller 1 or controller 2.
function MainCtrl($rootScope, $scope, navService){
$scope.template = {};
$scope.loadCtrl1=function(param){
navService.loadCtrl1(param);
}
$scope.loadCtrl2=function(param){
navService.loadCtrl2(param);
}
$rootScope.$on('loadCtrl1', function(e, args){
$scope.template = {'url': 'temp1'};
});
$rootScope.$on('loadCtrl2', function(e, args){
$scope.template = {'url': 'temp2'};
});
}
I use a service for communication because i want to move the load controller functions in a child controller.
var myApp = angular.module('myApp',[]);
myApp.factory('navService', function($rootScope) {
return {
loadCtrl1:function(param){
$rootScope.$broadcast('loadCtrl1', {'id':param});
},
loadCtrl2:function(param){
$rootScope.$broadcast('loadCtrl2', {'id':param});
}
};
});
I know this solution is bad because the controllers are not yet created when a different template is inserted so my event listener will not fire. Also can I destroy the previous instances of the controller because switching between the two controllers makes my event fire multiple times.
function Child1Ctrl($scope, $rootScope){
$rootScope.$on('loadCtrl1', function(e, args){
alert(args.id);
});
}
function Child2Ctrl($scope, $rootScope){
$rootScope.$on('loadCtrl2', function(e, args){
alert(args.id);
});
}
You don't need to broadcast (and shouldn't be broadcasting) to make this happen.
In my experience, if you're broadcasting on the rootScope, you're probably working too hard.
A simpler way of loading the template is very similar to what you're doing:
my.NavService = function() {
this.template = 'index.html';
this.param = null;
};
my.NavService.prototype.setTemplate(t, p) {
this.template = t;
this.param = p;
};
my.ctrl = function($scope, nav) {
$scope.nav = nav;
$scope.load = function(t, p) {
nav.setTemplate(t, p);
};
};
my.ctrl1 = function($scope, nav) {
$scope.param = nav.param;
};
my.ctrl2 = function($scope, nav) {
$scope.param = nav.param;
};
module.
service('nav', my.NavService).
controller('mainCtrl', my.ctrl).
controller('ctrl1', my.ctrl1).
controller('ctrl2', my.ctrl2);
<script type="text/ng-template" id="temp1.html">
<div ng-controller="ctrl1">Foo {{param}}.</div>
</script>
<script type="text/ng-template" id="temp2.html">
<div ng-controller="ctrl2">Bar {{param}}.</div>
</script>
<div ng-controller="mainCtrl">
<a ng-click="load('temp1.html', 16)">Load 1</a>
<a ng-click="load('temp2.html', 32)">Load 2</a>
<div ng-include src="nav.template"></div>
</div>
A setup like this would work much better for you.
Alternatively, you should look into selectively showing elements with ng-switch. Unlike ng-show/hide, ng-switch does not simply add "display:none" to the CSS. It removes it from the DOM.
Some notes:
The above example may not be a working example, it's a demonstration of the idea.
A working example can be seen here: http://jsbin.com/ofakes/1 It modifies your original code.
JSFiddle had some issues with loading the include from the on page script
tag.
JSBin was a little better.
I didn't really get it to work as expected until I broke out the templates
into their own files.