I'm writing an angular app where I need to bind values to some child scope.
In the controller, I have:
var addToStack = function(fallingItemOrder, scope) {
scope.model.stageChimneys[fallingItemOrder].Stack += 1;
return (scope.model.stageChimneys[fallingItemOrder].Stack === 3);
};
Where scope is referenced to $scope with $id=2 (I guess it's 2 because it lives under an ng-view directive.)
The main view has this code:
<ul class="chimneysUL">
<li ng-repeat="chimney in model.stageChimneys" ng-include="model.chimneyUrl"></li>
</ul>
And the ng-include fetches this sub-view, which is rendered 5 times with different data:
<div class="chimney" id="{{chimney.LetterCode}}" data-order="{{$parent.$index}}">
<div class="pipeHead"></div>
<div class="pipeBody">
<table class="ulInsertedLetters">
<tr ng-repeat="i in model.getNumber(model.stackSize) track by $index" ng-class="3 - $index <= chimney.Stack ? 'showInserted' : 'hideInserted'">
<td>
<img class="insertedLetterImg" data-ng-src="{{'../../Images/Cards/rectangle.jpg'}}" />
</td>
</tr>
</table>
</div>
<div class="picContainer">
<img class="card" data-ng-src="{{chimney.PicName}}" />
</div>
</div>
All bindings seem to be correct (e.g. chimney.LetterCode etc..)
but when addToStack executes, the {{chimney.Stack}} remains unchanged.
As I understand scopes, if the parent scope with $id = 2 has it's model properties change, then those changes should permeate down and reflect instantaneously in the html view.
And indeed in debugging, I can see that diving into $$childTail --> $$prevSibling, the chimney object has it's Stack property incremented.
So what's the missing part I've overlooked?
There's an issue in conception. Whatever's inside your included template shouldn't try and access what's outside. You should use a directive instead.
I'm not 100% sure, but I think that ng-include creates another scope. So whatever modification that happens in your main view is not reported to your included template because the value in that new scope wasn't changed.
Edit:
If you call your function from outside a digest (for instance in a callback passed to a 3rd-party library, on in a setTimeout function), the view will not be updated, because angular has no way of knowing a value has changed.. In that case, you have to surround your call with a $scope.$apply() call.
Related
I have a directive and it works fine in a way such that when I type something the search() scope function inside my directive fires and sets $scope.query with the input text.
here is the directive template
<div class="container">
<div class="system-filter-header">
<div class="no-gutter">
<div class="system-search-wrapper search-wrapper-width">
<i ng-click="search($evt)" class="fa fa-search"></i>
<input type="text" ng-keyup=search($evt) class="search pull-left suggesstions-styles"
ng-model="query" ng-attr-placeholder="Search...">
</div>
</div>
</div>
</div>
here is the scope function which gets triggered
$scope.search = function() {
console.log($scope.query.length)
}
But when I used an ng-if="true" in first line of template (true used for generalizing only, I want to do a different conditional check inside ng-if) such that,
<div class="container" ng-if="true">
still the search gets triggered but the console.log gives always 0 and it doesn't seem to update the $scope.query value as it stays as $scope.query = ''
throughout the typing.
EDIT
Here is a an example codepen with almost similar behaviour. The problem is with the searchBox directive and I have added ng-if=true to the template but searching doesn't work. When I remove the ng-if searching works fine.
Any reason for this?
Rule of thumb in AngularJS: your ng-model should always include a dot. Otherwise AngularJS directives that create child scopes (like ng-if or ng-repeat) will create a duplicate property on that child scope instead of the parent scope. Following the controllerAs convention completely mitigates this behavior.
I have a list of posts with comments. I need to traverse through array of comments inside each of the posts on my page. I'm trying to create variable inside ngRepeat for posts which I can use like an indexer to display exact comment for each post. Due to ngRepeat creating nested scope, this variable must be unique for each iteration. But when I'm trying to change it with ng-click, it doesn't change.
My ngRepeat:
<div class="question_block col-xs-12"
ng-repeat="answer in question.content.answer track by answer.id">
is followed by <span style="display:none">{{counter=0}}</span>. And then I'm showing some items like <span>{{answer.comments[counter].user.organization.title}}</span>. When I'm trying to do something like <a href ng-click="counter++">Increment</a> nothing happens. What's the matter ?
Use ng-init="counter = 0" and attach your ng-click to a function in your controller:
<div ng-repeat="item in items track by $index" ng-init="counter=0">
{{item}} ({{counter}})
<button ng-click="clickHandler()">Increment</button>
<hr />
</div>
Then, to increment counter in the context of the event, use this.counter
$scope.clickHandler = function() {
this.counter++;
};
Plunker demo : http://plnkr.co/edit/J4d0JlJSKD7i4OfMT2r4?p=preview
This is weird as it should be pretty straightforward. I will post my code first and then ask the question:
html -
<div ng-controller="myController" ng-switch on="addressCards">
<div>
{{addCustom}} // does not get changed
<div ng-if="addCustom === false">
{{addCustom}} // does get changed
<button type="button" class="btn btn-primary btn-icon-text" ng-click="addCustom = true">
<span class="icon icon-plus"></span>
click here
</button>
</div>
</div>
</div>
controller -
(function(){
'use strict';
angular.module('myApp')
.controller('myController',['$scope',myController]);
function myController($scope){
$scope.addCustom = false;
}
})();
So I simply introduced a scope variable - addCustom - in my controller and set it to false as default. This variable controls if a div is shown or not. I am also outputting the value of the scope on the html at 2 different locations. Please see above.
But when I change its value in an ng-click within this divs, its value is changing at the second location(within the div) but not the first one(outside the div). Because of this the div does not change state as well.
I am not able to figure what might be possibly wrong here. Can someone please help?
The thing happening is when you have ng-repeat,ng-switch and ng-if directive, angular creates child scope for those element wherever they are placed. Those newly created scope are prototypically inherited from there parent scope.
On contrast Prototypal Inheritance means?
If you have scope hierarchy, then parent scope property are accessible inside child scope, only if those property are object (originally object referenced is passed to child scope without creating its new reference). But primitive datatypes are not accessible inside child scope and if you looked at your code addCustom scope variable is of primitive dataType.
Lets discuss more about it.
Here you have myController controller which has addCustom scope variable of primitive type & as I said above ng-switch & ng-if directive are compiled they do create new child scope on that element. So in your current markup you have ng-switch on ng-controller="myController" div itself. For inner html it had created a child scope. If you wanted to access parent scope inside child(primitive type) you could use $parent notation before scope variable name. Now you can access the addCustom value by $parent.addCustom.
Here its not over when angular compiler comes to ng-if div, it does create new child scope again. Now inner container of ng-if will again have child scope which is prototypically inherited from parent. Unfortunately in your case you had primitive dataType variable so you need to use $parent notation again. So inside ng-if div you could access addCustom by doing $parent.$parent.addCustom. This $parent thing will solve your problem, but having it on HTML will make unreadable and tightly couple to its parent scope(suppose on UI you would have 5 child scope then it will look so horrible like $parent.$parent.$parent.$parent). So rather you should go for below approach.
Follow Dot rule while defining ng-model
So I'd say that you need to create some object like $scope.model = {} and add addCustom property to it. So that it will follow the prototypal inheritance principle and child scope will use same object which have been created by parent.
angular.module('myApp')
.controller('myController',['$scope',myController]);
function myController($scope){
$scope.model = { addCustom : false };
}
And on HTML you will use model.addCustom instead of addCustom
Markup
<div ng-controller="myController" ng-switch on="addressCards">
<div>
{{model.addCustom}} // does not get changed
<div ng-if="model.addCustom === false">
{{model.addCustom}} // does get changed
<button type="button" class="btn btn-primary btn-icon-text" ng-click="model.addCustom = true">
<span class="icon icon-plus"></span>
click here
</button>
</div>
</div>
</div>
Other best way to deal with such kind of issue is, use controllerAs pattern while using controller on HTML.
Markup
<div ng-controller="myController as myCtrl" ng-switch on="addressCards">
<div>
{{myCtrl.addCustom}} // does not get changed
<div ng-if="myCtrl.addCustom === false">
{{myCtrl.addCustom}} // does get changed
<button type="button" class="btn btn-primary btn-icon-text" ng-click="myCtrl.addCustom = true">
<span class="icon icon-plus"></span>
click here
</button>
</div>
</div>
</div>
From the Docs:
The scope created within ngIf inherits from its parent scope using prototypal inheritance. An important implication of this is if ngModel is used within ngIf to bind to a javascript primitive defined in the parent scope. In this case any modifications made to the variable within the child scope will override (hide) the value in the parent scope.
-- AngularJS ng-if directive API Reference
The rule of thumb is don't bind to a primitive, instead bind to an object.
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-if, ng-switch, ng-view and ng-include all create new child scopes, so the problem often shows up when these directives are involved. (See this example for a quick illustration of the problem.)1
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.1
Ng-if introduces a different scope. Try this as an attribute of your button:
ng-click="$parent.addCustom = false"
This will assure that you're accessing the same scope.
It's because of this that it's always good practice to use the ControllerAs syntax. All attributes are bound to the controller object and namespaced accordingly, meaning you never run in to this problem. I've updated your example using the ControllerAs syntax to demonstrate its use.
HTML
<div ng-controller="myController as vm" ng-switch on="addressCards">
<div>
{{vm.addCustom}}
<div ng-if="vm.addCustom === false">
{{vm.addCustom}}
<button type="button" class="btn btn-primary btn-icon-text" ng-click="vm.addCustom = true">
<span class="icon icon-plus"></span>
click here
</button>
</div>
</div>
</div>
Controller
(function(){
'use strict';
angular.module('myApp')
.controller('myController', [ myController ]);
function myController () {
var vm = this;
vm.addCustom = false;
}
})();
Here is an excellent article providing more detail about ControllerAs and it's advantages.
Both Classic Controller and Controller As have $scope. That's super important to understand. You are not giving up any goodness with either approach. Really. Both have their uses.
I have a <ul> that gets populated with the server. But in that controller there is also an iframe. When the <li>'s arrive there is some disconnect between them and the iframe even though they are in the same controller.
When you click one of the li's it should change the class on the iframe but it's not. However, If I move the iframe inside of the ng-repeat that injects the iframe it works.
View
<div class="content" ng-controller="FeedListCtrl">
<ul>
<li ng-repeat="item in items">
<div data-link="{{item.link}}" ng-click="articleShowHide='fade-in'">
<div ng-bind-html="item.title" style="font-weight:bold;"></div>
<div ng-bind-html="item.description"></div>
<!-- it works if i put the iframe here -->
</div>
</li>
</ul>
<!-- doesn't work when the iframe is here -->
<iframe id="article" ng-class="articleShowHide" src=""></iframe>
</div>
Here is the controller. It does an ajax call to get the data for each <li>
Controller
readerApp.controller('FeedListCtrl', ["$scope", "$http", "FeedListUpdate", function ($scope, $http, FeedListUpdate) {
$scope.setFeed = function (url) {
$http.get('feed?id=' + FeedListUpdate.GetCurrentFeedUrl()).success(function (data) {
$scope.items = data.currentFeed.items;
});
};
}]);
When inside of an ng-repeat you are in a different scope which means you are not setting the variable you think you are. Use $parent and that should work. The syntax is:
<div data-link="{{item.link}}" ng-click="$parent.articleShowHide='fade-in'">
Side note for others finding this - sometimes adding curly brackets helps as well. For more information on ng-class see here: http://docs.angularjs.org/api/ng/directive/ngClass
An Example
In case anyone wants to see this in action, I put together an example demonstrating a few ways to set the class as well as demonstrating the issue in scope (See: http://plnkr.co/edit/8gyZGzESWyi2aCL4mC9A?p=preview). It isn't very pretty but it should be pretty clear what is going on. By the way, the reason that methods work in this example is that the scope doesn't automatically redefine them the way it does variables so it is calling the method in the root scope rather than setting a variable in the repeater scope.
Best of luck!
I am trying to ng-click assign a variable (success) inside an ng-repeat and then use that value outside of the ng-repeat(failure) as follows:
<div class="stocksNav col s1">
<div class="myStockList" ng-repeat="stocksInPortfolio in ctrl.myPortfolio.stocksInPortfolio">
<ul>
<li style="position: relative"><a href ng-click="ctrl.tab = stocksInPortfolio.stock._id">{{stocksInPortfolio.stock.name | limitTo:10}}</a></li>
</ul>
<div class="myStockView" ng-show="ctrl.tab === stocksInPortfolio.stock._id">
<div class="{ active:ctrl.tab === stocksInPortfolio.stock._id }">
</div>
</div>
</div>
</div>
<div ng-include="'/app/dashboard/partials/myIndividualStock.html'"></div>
the partial wants to then call ctrl.tab to use it's click event assigned values, such that if i ng-click on any other instance of the ng-repeat function the ctrl.tab variable will reassign, but the ctrl.tab assignment does not persist outside of the ng-repeat div. any thought?
The ng-repeat directive (as many other directives) creates a new scope, and to access a parent's scope variable, it needs to be an object. In other words, instead of ctrl.tab, initialize a object $scope.something = {} in your controller, then use ctrl.something.tab in your template (replace something with a name proper to your application).