How to resolve main controller first then its child controller - angularjs

I have a controller as main controller and a its child controller. I want to execute first the main controller and then after its child controller.
I am collecting some userdata and want to keep it in $rootScope so that i could access it within the whole application.
How could i do this ?
<body ng-app="angularApp">
<div ng-controller="MainAppController">
<div ng-controller="childController">
Here i want to access data from "MainAppController" stored in $rootScope
But problem is "childController" runs before "MainAppController"
</div>
</div>
</body>
Here is the angular code
angular.module('MyApp').controller('MainAppController', function($rootScope, service){
$rootScope.userData = [];
service.getUserData().success(function(userDetails){
$rootScope.userData = userDetails;
});
});
angular.module('MyApp').controller('childController', function($scope, $rootScope){
$scope.userInfo = $rootScope.userData;
//Here $scope.userInfo is null because $rootScope.userData gets assigned to $scope.userInfo in this controller before userDetails gets assigned to $rootScope.userData in MainAppController controller.
I want that untill "$rootScope.userData = userDetails;" is not finished , "$scope.userInfo = $rootScope.userData;" must not run.
How can i do this ?
});

There are two ways i know you can do this.
1 way ::
Use $rootScope.userData directly in html and when your parent controller will run $rootScope.userData will get updated and by dual binding feature of angular, your view will get updated accordingly
Code::
//angularjs Code
var app = angular.module('MyApp', []);
app.controller('MainController', function($rootScope, $timeout) {
$rootScope.userData = {};
$timeout(function() {
$rootScope.userData = {name:'myName'};
}, 3000);
});
app.controller('childController', function() {
});
//html code
<div ng-app="MyApp" ng-controller="MainController">
<div ng-controller="childController">
{{userData.name}}
</div>
</div>
2 way::
You can attach $watch on $rootScope.userData in childController so when $rootScope.userData will get updated $watch will run and inside $watch you can update your $scope variable
Code::
//Angularjs Code
var app = angular.module('MyApp', []);
app.controller('MainController', function($rootScope, $timeout) {
$rootScope.userData = {};
$timeout(function() {
$rootScope.userData = {name:'myName'};
}, 2000);
});
app.controller('childController', function($scope, $rootScope) {
$scope.$watch(function(){
return $rootScope.userData;
}, function(){
$scope.userInfo = $rootScope.userData;
});
});
//HTML Code
<div ng-app="MyApp" ng-controller="MainController">
<div ng-controller="childController">
{{userInfo.name}}
</div>
</div>

Related

How can i get a variable from one controller and then pass the same variable to view

I have two controllers ParentController and ChildController I have a variable in ParentController and i need to get that variable to ChildController and then i need to pass it to the view and one more thing is i should not use the $scope in child controller and parentController. Is it possible ?if not is there any way to use it with out $scope.
app.controller('ParentController', function($scope) {
$scope.exampleVariable = "test";
});
app.controller('ChildController', function($scope, $controller) {
var someScopeVariable = this;
$controller('ParentController', {$scope: someScopeVariable });
console.log(someScopeVariable.exampleVariable)
someScopeVariable.exampleVariable = "Updatetest";
});
Now in my html view i need to use exampleVariable
like this
<div ng-controller="ChildController as child">
<h1>{{child.exampleVariable}}</h1>
</div>
How can i get the value from parentcontroller to html view.
You can always use a service to share data between controllers.
create a service
app.service('myservice', function() {
var myVar;
this.setMyVar = function(value){
this.myVar = value
}
this.getMyVar = function(){
return this.myVar;
}
});
pass it as a dependency and you can have the value shared.
app.controller('ParentController',['$scope', 'myservice', function($scope, myservice) {
$scope.exampleVariable = "test";
myservice.setMyVar("test");
}]);
you can pass it to other controller as a dependency too and you can do a getMyVar there!!
You can use Broadcast and On in the Controller-
app.controller('ParentController', function($scope) {
var self = this;
$scope.$broadcast('exampleVariable', 'test');
});
and in child controller -
app.controller('ChildController', function($scope, $controller) {
var someScopeVariable = this;
$controller('ParentController', {$scope: someScopeVariable });
console.log(someScopeVariable.exampleVariable)
$scope.$on('exampleVariable', function(event, data) {
someScopeVariable.exampleVariable = data;
});
});
There are some ways you can achieve this.
1. Through $rootScope.
2. By Creating Service.
3. Inheriting parent controller to children controller.
2 & 3 are already provided in other answers. Follow this if you want to achieve it using $rootScope.
JS :
var app = angular.module('myApp', []);
app.controller('ParentController', function($scope, $rootScope) {
$rootScope.exampleVariable = "test";
});
app.controller('ChildController', function($scope) {
});
HTML :
<div ng-controller="ParentController">
Parent Controller : {{exampleVariable}}
<hr/>
</div>
<div ng-controller="ChildController">
Children Controller : {{exampleVariable}}
</div>
DEMO LINK.
Note : You can also override the scope variable in children controller by adding the below code in ChildController :
$scope.exampleVariable = "overriding...";

controller use $scope? custom service use this?

I found in Controller, we use $scope, here is the link (http://www.w3schools.com/angular/tryit.asp?filename=try_ng_controller).
I change $scope to this, it cannot work.
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
$scope.firstName = "John";
$scope.lastName = "Doe";
});
</script>
However, I found in Service, we use this, here is the link (http://www.w3schools.com/angular/tryit.asp?filename=try_ng_services_custom).
In hexafy service, I change this to $scope, it cannot work.
<script>
var app = angular.module('myApp', []);
app.service('hexafy', function() {
this.myFunc = function (x) {
return x.toString(16);
}
});
app.controller('myCtrl', function($scope, hexafy) {
$scope.hex = hexafy.myFunc(255);
});
</script>
Does my above summary correct? If not, what should be correct summary considering all kinds of possible.
You can use this instead of $scope in controller as well. They have brought in controller as syntax(from Angular 1.2). You can attach data to this(Here controller holds the data). But internally it will be attached to $scope only, but you don't have to attach it manually. It has to be declared in html like this , controller is declared as main , so we have to refer to data in html using main.
<div ng-controller="MainCtrl as main">
{{ main.title }}
</div>
app.controller('MainCtrl', function ($scope) {
this.title = 'Some title';
console.log("Title" + $scope.main.title); // It will print some title in the console.
});

Angularjs - Calling only one of many subcontrollers/ multiple controllers

I have an index page wherein I define two controllers. I want to call one main controller always (should be rendered always) and the other is called only for specific sub URL calls. Should I make one nested within another, or I can keep them independent of each other? I don't have access to change routes or anything, only the controller.
Right now when I use the template (HTML) mentioned, it calls/renders both controllers, even though url is say /index
Only for /index/subPage, I want both controllers to be rendering.
/index
/index/subPage
HTML:
<div ng-controller="MainCtl" ng-init=initMain()>
<p> Within ctller2 {{results}} </p>
</div>
<div ng-controller="Ctller2"> <!-- should not be displayed unless /subPage/mainUrl is rendering -->
<p> Within ctller2 {{results}} </p>
</div>
JS:
app.controller('MainCtl', ['$scope', '$http', '$location', function ($scope, $http, $location) {
$http.get('xx/mainUrl').then(function(data) {
$scope.results = someDataJSON;
console.log(someDataJSON);
});
$scope.initMain = function() {
$scope.initMethods();
}
}]);
app.controller('Ctller2', ['$scope', '$http', '$location', function ($scope, $http, $location) {
// This controller gets initialized/rendered/called even when xx/mainUrl is called, and when xx/subPage/mainUrl is called too..
$http.get('xx/subPage/mainUrl').then(function(data) {
$scope.results = someDataJSON;
console.log(someDataJSON);
})
$http.get('xx/subPage').then(function(data) {
$scope.results = data.data;
console.log(data);
})
angular.element(document).ready(function () {
alert('Hello from SubCtl, moving over from main controller to here');
});
}]);
What am I doing wrong? I'm new to Angular.js
You can conditionally initiate a controller using ng-if. So you could try something like this:
<body ng-controller="MainCtrl">
<div ng-controller="ctrl1">{{hello}}</div>
<div ng-controller="ctrl2" ng-if="showCtrl2">{{hello}}</div>
</body>
and then set the value of the variable in a parent controller by checking the current url using $location.path()
var app = angular.module('plunker', []);
app.config(function($locationProvider){
$locationProvider.html5Mode(true);
});
app.controller('MainCtrl', function($scope, $location) {
$scope.showCtrl2 = ($location.path() === 'my path');
});
app.controller('ctrl1', function($scope){
$scope.hello = 'ctrl1 says hello';
});
app.controller('ctrl2', function($scope){
$scope.hello = 'ctrl2 says hello';
});
But it's a bit hacky and for a larger project a more robust solution would require using something like ui.router.

How to change a value of a "Value" service?

I created an injectable value used in the entire application. Recently, I want to change it value. Here is the simulation of my situation:
angular.module('app', ['ngRoute']) // Create a value
.value('myValue','foo');
angular.module('app')
.controller('firstCtrl', ['$scope', '$filter', 'myValue', function($scope, $filter, myValue){
myValue = 'bar';
console.log(myValue); // bar
}])
.controller('secondCtrl', ['myValue', function(myValue){
console.log(myValue); // foo
}]);
However, the value of myValue didn't change at all, as you can see in the secondCtrl. How can I change this value? Any suggestion would be appreciated.
Google 'angular dot rule', and you've got twice defined app module.
Please see demo below.
var app = angular.module('app', []);
angular.module('app') // Create a value
.value('myValue', {
data: 0
});
app.controller('homeCtrl', function($scope, myValue) {
$scope.value = myValue;
$scope.update = function() {
myValue.data = 8;
}
});
app.controller('secondCtrl', function($scope, myValue) {
$scope.value = myValue;
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<body>
<div ng-app="app">
<div ng-controller="homeCtrl">
<button ng-click="update()">update</button>
<br/>home: {{value.data}}
</div>
<hr/>
<div ng-controller="secondCtrl">
second: {{value.data}}
</div>
</div>
</body>

How to communicate between controllers of two different modules in AngularJs

I want to know that can we communicate between two different controllers in AngularJS. Suppose I have Two modules,
Plunker: http://plnkr.co/edit/if0MQwlx9WHrD8XnMi2t?p=preview
1. var app = angular.module('fistModule', []);
app.controller('first', function ($scope) {
$scope.firstMethod= function () {
//my code}
} )
2. var newapp = angular.module('secondModule,[]');
newapp.controller('second', function ($scope) {
$scope.secondMethod= function () {
//my code}
Is there way to communicate between controllers of two different modules.
My Code:
JS:
angular.module('myApp', [])
.controller('ParentCtrl', ['$scope',
function($scope) {
$scope.message = "Child updated from parent controller";
$scope.clickFunction = function() {
$scope.$broadcast('update_parent_controller', $scope.message);
};
}
]);
angular.module('myNewApp', [])
.controller('ChildCtrl', ['$scope',
function($scope) {
$scope.message = "Some text in child controller";
$scope.$on("update_parent_controller", function(event, message) {
$scope.message = message;
});
}
])
HTML:
<div ng-app="myApp" ng-controller="ParentCtrl">
<div ng-app="myNewApp" ng-controller="ChildCtrl">
<p>{{message}}</p>
</div>
<button ng-click="clickFunction()">Click</button>
</div>
As #JB Nizet says, you do it the exact same way. You use a service to communicate between two controllers.
One module needs to have the other module as a dependency. This is always a one-way dependency. I have made secondModule a dependency of firstModule.
As well, the value in the service is stored in an object called data. This is because JavaScript does not pass values by reference -- but does pass objects by reference. So this is a form of boxing.
angular.module('firstModule', ['secondModule'])
.controller('FirstController', FirstController)
.service('sharedData', SharedData);
FirstController.$inject = ['sharedData'];
function FirstController(sharedData) {
this.data = sharedData.data;
}
function SharedData() {
this.data = {
value: 'default value'
}
}
angular.module('secondModule', [])
.controller('SecondController', SecondController);
SecondController.$inject = ['sharedData'];
function SecondController(sharedData) {
this.data = sharedData.data;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="firstModule">
<div ng-controller="FirstController as vm">
First Controller in module firstModule<br>
<input type=text ng-model="vm.data.value" />
</div>
<div ng-controller="SecondController as vm">
Second Controller in module secondModule<br>
{{vm.data.value}}
</div>
</div>
your plunker has a very minor issue.
change this
angular.module('myApp', [])
to
angular.module('myApp', ['myNewApp'])

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