I was wondering :
Just as without using controller as syntax , I'd have to do :
<body ng-controller="ParentCtrl">
<input ng-model="name" /> {{name}}
<div ng-controller="ChildCtrl">
<input ng-model="name" /> {{name}} - {{$parent.name}}
</div>
</body>
And now with the Controller as syntax , I can do :
<body ng-controller="ParentCtrl as parent">
<input ng-model="parent.name" /> {{parent.name}}
<div ng-controller="ChildCtrl as child">
<input ng-model="child.name" /> {{child.name}} - {{parent.name}}
</div>
</body>
Which is great , but what about the controller itself ?
With the first example , I could do :
....controller('Controller', function($scope) {
// do something with $parent.$scope...
But now , after using this :
....controller('Controller', function() {
//this.mySomething....
Question :
How would I reference the parent ? ( in the alias way!)
I mean , NG come here to help us by using aliases to scope via parent && child ,
But is there any representation to that "help" in the controller ?
No, there isn't.
The goal of the Controller as ... was to make dealing with models more natural, and to remove all of the mess of dealing with $scope, except when needed.
Models don't really have $parents.
$scope has a parent-$scope.
But if I have a parent Controller as "Bike" and a nested controller "Doorknob"...
Doorknob might have .turn() and .type and .locked, but it doesn't have a "Bike", any more than all "Bike"s have "Doorknobs".
You still have direct-access to the $scope in the controller, so you can add your own inheritance, and build your own links -- you can also still reference other $scope properties in your view...
Related
I am new to Angular JS, and I am learning it through the tutorials,
my question is why my model is not updating the view?
Following is the code.
<!DOCTYPE html>
<div ng-controller="MyContr">
{{xxx}}
</div>
<input type="text" ng-model="xxx" ng-controller="MyContr" />
<script>
var app = angular
.module("MyApp", [])
.controller("MyContr", function ($scope) {
var xxx="Alexander"
$scope.xxx = xxx;
});
</script>
According to the code shown on the question, It seems that your are calling MyContr twice,
one here:
<div ng-controller="MyContr">
{{xxx}} <!-- xxx (instance 1) -->
</div>
and another here:
<!-- xxx (instance 2) -->
<input type="text" ng-model="xxx" ng-controller="MyContr" />
... so two (different) instances of the same controller are being created. This way each instance have two different xxx var, each one has its own xxx variable on its scope.
Solution
Option 1 - You can share the data between instances (see Share data between AngularJS controllers and AngularJS: How can I pass variables between controllers?)
Option 2 - Enclose both html elements inside the same instance of the MyContr like this:
<span ng-controller="MyContr">
<div>
{{xxx}}
</div>
<input type="text" ng-model="xxx" />
</span>
Can I use ng-model to build up an object over several views?
For instance, say in view1 I have
<input ng-model='myObject.firstName'>
And in view2 I have
<input ng-model='myObject.lastName'>
And in view3 I have
<input ng-model='myObject.email'>
The idea being you could hit a submit button in the last view, and return the object somewhere.
My initial approach to this is to have a service which declares an empty object, then have functions in the service which allow the controllers using the service to add their view input to that object, then return the object.
However I feel like this is quite a roundabout way of doing it!
If anyone could point me in the right direction I would really appreciate it.
You can use a service for that. Here an example with 3 controllers sharing the same object using 3 directives ng-model. Each controller modify the tested.value property, but you can use differents properties of course.
angular.module('test', []).factory('tested', function() {
return {
value : '123'
};
}).controller('ctrl1', function($scope, tested) {
$scope.tested = tested;
}).controller('ctrl2', function($scope, tested) {
$scope.tested = tested;
}).controller('ctrl3', function($scope, tested) {
$scope.tested = tested;
})
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="test">
<div ng-controller="ctrl1">
<input type="text" ng-model="tested.value" />
{{ tested.value }}
</div>
<div ng-controller="ctrl2">
<input type="text" ng-model="tested.value" />
{{ tested.value }}
</div>
<div ng-controller="ctrl3">
<input type="text" ng-model="tested.value" />
{{ tested.value }}
</div>
</div>
Since each view has its controller, the only way to share data is with a service of type "provider", "service" or "factory".
You could then modify your object from each controller with the methods you talk about.
In the end, to notify each view something changed, the service methods could raise an event from the service :
$rootScope.$broadcast('somethingChanged', myObject);
And each controller could listen with:
$scope.$on('somethingChanged', function(data) {
});
I have got a form where user will enter a name and click Next. What I want to do is that, when the user clicks Next, I want to alert the updated value of $scope.name inside toChat function, but initial value is alerted, which is James. How can I access the updated value inside angular function? I have some serious problems understanding sharing variables within AngularJs.
js
.controller('NewcontactCtrl', function($scope,$rootScope, $ionicHistory,$window) {
$scope.name='James';
$scope.myGoBack = function() {
$ionicHistory.goBack();
};
$scope.toChat = function() {
alert($scope.name);
};
})
html
<ion-view view-title="New contact">
<ion-nav-back-button>
</ion-nav-back-button>
<ion-nav-buttons side="primary">
<button class="button" ng-click="myGoBack()">
Cancel
</button>
</ion-nav-buttons>
<ion-nav-buttons side="secondary">
<button class="button" ng-click="toChat()" >
Next
</button>
</ion-nav-buttons>
<ion-content scroll="false" has-header="false" padding="true" >
<div class="list">
<label class="item item-input">
<input type="text" placeholder="Name" ng-model="name" />
</label>
<label class="item item-input">
<textarea placeholder="Notes" ng-model="notes" rows="10"></textarea>
</label>
</div>
</ion-content>
</ion-view>
Can anyone help ?
Please see: https://github.com/angular/angular.js/wiki/Understanding-Scopes
The most relevant part in the above:
Scope inheritance is normally straightforward, and you often don't even need to know it is happening... until you try 2-way data binding (i.e., form elements, ng-model) to a primitive (e.g., number, string, boolean) defined on the parent scope from inside the child scope. It doesn't work the way most people expect it should work. What happens is that the child scope gets its own property that hides/shadows the parent property of the same name. This is not something AngularJS is doing – this is how JavaScript prototypal inheritance works. New AngularJS developers often do not realize that ng-repeat, ng-switch, ng-view and ng-include all create new child scopes, so the problem often shows up when these directives are involved. ...
This issue with primitives can be easily avoided by following the "best practice" of always have a '.' in your ng-models – watch 3 minutes worth. Misko demonstrates the primitive binding issue with ng-switch.
Having a '.' in your models will ensure that prototypal inheritance is in play. So, use
<input type="text" ng-model="someObj.prop1"> rather than
<input type="text" ng-model="prop1">.
I believe you have a directive in there somewhere (probably ion-content) that is creating a new scope where your input field is, separated from the scope where your Next button is.
To simulate this, I've used ng-repeat in the below snippet (but I'm repeating only once), which causes the same behaviour of splitting the scopes. If you were to use your controller code unmodified with this html, you'd reproduce the issue you're experiencing.
The solution around this is to 'use a dot (.)' when binding. Notice that I've wrapped the name within an object called 'data' on the scope, so now you refer to this as data.name instead of just name.
(function() {
'use strict';
angular.module('myApp', [])
.controller('NewcontactCtrl', function($scope, $window) {
$scope.repeaterTest = [1];
$scope.data = {name: 'James'};
$scope.toChat = function() {
$window.alert($scope.data.name);
};
});
})();
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.28/angular.min.js"></script>
<div ng-app="myApp">
<div ng-controller="NewcontactCtrl">
<label ng-repeat="test in repeaterTest">
<input type="text" placeholder="Name" ng-model="data.name" />
</label>
<button class="button" ng-click="toChat()">
Next
</button>
</div>
</div>
I think you need to alert something similar to...
alert($scope.name)
Addition to #Paul Fitzgerald, points, ensure that ng-controller="NewcontactCtrl" is included at the top scope in HTML DOM.
try adding a service in order to share data within scopes
.controller('NewcontactCtrl', function($scope,$rootScope,sharedData $ionicHistory,$window) {
$scope.name=sharedData.Name ;
$scope.myGoBack = function() {
$ionicHistory.goBack();
};
$scope.toChat = function() {
alert(sharedData.Name);
};
});
app.factory('sharedData', [function () {
var self = {};
self.Name = "James";
return self;
}]);
I'm looking into having a dynamically generated binding where binding itself is evaluated/calculated beforehand. Something like:
<span ng-repeat="extra2 in product.extra2">
<input type="checkbox" checkbox-group />
<label>{{extra2.extra_0}}</label> //this complete work
<label>{{extr_price}}</label> //this not work
</span>
It doesn't work as is.
ngBind or ngBindTemplate are not useful.
Controller
$scope.extr_price = 'extra2.extra_0';
It should be {{extra2['extr_price']}}
and in controller:
$scope['extr_price'] = $scope.extra2['extra_0'];
Solved this it
controller: $scope['extr_price'] = 'extra_0';
view : {{extra2[extr_price]}}
I was using ng-include on a few of my pages, however I had to stop using ng-include because it was breaking the angular-ui datepicker. I opened this Github bug.
I am wondering if anyone else was having issues with directives not functioning the same way when being used as part of a ng-include.
Is there a way to make the datepicker work as expected as part of a ng-include?
Here is a plunker showing how it is broken. http://plnkr.co/edit/AboEJGxAK3Uz76CfpaZ0?p=preview
Here is the html that works when on the view, but does not work when part of a ng include.
<div class="row">
<div class="col-md-2">
<p class="input-group">
<input type="text" class="form-control" datepicker-popup="yyyy/MM/dd" ng-model="something.dt2" is-open="secondCal"
min-date="minDate" name="secondCal" max-date="'2015-06-22'" datepicker-options="dateOptions"
date-disabled="disabled(date, mode)" ng-required="true" close-text="Close"/>
<span class="input-group-btn">
<button type="button" class="btn btn-default" style="line-height: 1.2em" ng-click="open($event, 'secondCal')">
<i class="ss-icon ss-calendar"></i>
</button>
</span>
</p>
</div>
</div>
Here is the JS from the controller.
$scope.open = function ($event, elementOpened) {
$event.preventDefault();
$event.stopPropagation();
$scope[elementOpened] = !$scope[elementOpened];
};
And two ways I was doing ng-include
<div ng-include src="'dist/partials/myPartial.html'"></div>
<div ng-include="'dist/partials/myPartial.html'"></div>
Update
I found that this is because the ng-include directive creates a new scope for each include. This SO post creates a new directive that does the include without creating a new scope. However there seems there "should" be a way to fix it without using a different include.
The datepicker will be unable to open as soon as the is-open is changed by the datepicker directive itself (e.g. click outside to close the datepicker).
This is a common issue regarding the "Prototypal Inheritance" characteristic of scope.
For a complete detail, you could read this: Understanding-Scopes
You could easily solve this by not storing any primitive values directly into $scope, but some object and using dot-notation like this:
<input type="text" class="form-control"
datepicker-popup="yyyy/MM/dd" ng-model="something.dt2"
is-open="model.secondCal"
and in your controller:
app.controller('MainCtrl', function($scope) {
$scope.model = {};
$scope.open = function($event, elementOpened) {
$event.preventDefault();
$event.stopPropagation();
$scope.model[elementOpened] = !$scope.model[elementOpened];
};
});
Example Plunker: http://plnkr.co/edit/dJNIwSz2Uot3McmIMhd4?p=preview
I've created Plunker to debug it but it works fine with your code
http://plnkr.co/edit/nxYCiwRqdWMOkfZoRhGY?p=preview
<body ng-controller="MainCtrl">
<div ng-include="'partial.html'"></div>
</body>
after clarification and further tests i see that calendar with ng-include lose the scope when triggering the change not by scope method, the easy workaround would be as per this plunker
http://plnkr.co/edit/nxYCiwRqdWMOkfZoRhGY?p=preview
Don't remember which one of the angular team said it but if you don't have a dot in your model you are doing it wrong.
a little explanation why it works:
if you do
$scope.valueName = value
it will assign value to the current scope immediately
but if you do
$scope.something.valueName = value
what will happen is that angular will first locate $scope.something, if it doesn't exists on current scope it will look in parent (as long as you don't work in isolated scope)
then when it finds it it will assign value or return something like 'cant find valueName of undefined'
from the angularjs documentation:
https://docs.angularjs.org/api/ng/directive/ngInclude
This directive creates new scope.
This directive executes at priority level 400.