Develop Reference

Angular ng-model not binding to textarea [duplicate]

Here is my plnkr: http://plnkr.co/edit/n8cRXwIpHJw3jUpL8PX5?p=preview You have to click on a li element and the form will appear. Enter a random string and hit 'add notice'. Instead of the textarea text you will get undefined.
Markup:
<ul>
<li ng-repeat="ticket in tickets" ng-click="select(ticket)">
{{ ticket.text }}
</li>
</ul>
<div ui-if="selectedTicket != null">
<form ng-submit="createNotice(selectedTicket)">
<textarea ng-model="noticeText"></textarea>
<button type="submit">add notice</button>
</form>
</div>
JS part:
$scope.createNotice = function(ticket){
alert($scope.noticeText);
}
returns 'undefined'. I noticed that this does not work when using ui-if of angular-ui. Any ideas why this does not work? How to fix it?

Your problem lies in the ui-if part. Angular-ui creates a new scope for anything within that directive so in order to access the parent scope, you must do something like this:
<textarea ng-model="$parent.noticeText"></textarea>
Instead of
<textarea ng-model="noticeText"></textarea>

This issue happened to me while not using the ng-if directive on elements surrounding the textarea element. While the solution of Mathew is correct, the reason seems to be another. Searching for that issue points to this post, so I decided to share this.
If you look at the AngularJS documentation here https://docs.angularjs.org/api/ng/directive/textarea , you can see that Angular adds its own directive called <textarea> that "overrides" the default HTML textarea element. This is the new scope that causes the whole mess.
If you have a variable like
$scope.myText = 'Dummy text';
in your controller and bind that to the textarea element like this
<textarea ng-model="myText"></textarea>
AngularJS will look for that variable in the scope of the directive. It is not there and thus he walks down to $parent. The variable is present there and the text is inserted into the textarea. When changing the text in the textarea, Angular does NOT change the parent's variable. Instead it creates a new variable in the directive's scope and thus the original variable is not updated. If you bind the textarea to the parent's variable, as suggested by Mathew, Angular will always bind to the correct variable and the issue is gone.
<textarea ng-model="$parent.myText"></textarea>
Hope this will clear things up for other people coming to this question and and think "WTF, I am not using ng-if or any other directive in my case!" like I did when I first landed here ;)
Update: Use controller-as syntax
Wanted to add this long before but didn't find time to do it. This is the modern style of building controllers and should be used instead of the $parent stuff above. Read on to find out how and why.
Since AngularJS 1.2 there is the ability to reference the controller object directly instead of using the $scope object. This may be achieved by using this syntax in HTML markup:
<div ng-controller="MyController as myc"> [...] </div>
Popular routing modules (i.e. UI Router) provide similar properties for their states. For UI Router you use the following in your state definition:
[...]
controller: "MyController",
controllerAs: "myc",
[...]
This helps us to circumvent the problem with nested or incorrectly addressed scopes. The above example would be constructed this way. First the JavaScript part. Straight forward, you simple do not use the $scope reference to set your text, just use this to attach the property directly to the controller object.
angular.module('myApp').controller('MyController', function () {
this.myText = 'Dummy text';
});
The markup for the textarea with controller-as syntax would look like this:
<textarea ng-model="myc.myText"></textarea>
This is the most efficient way to do things like this today, because it solves the problem with nested scopes making us count how many layers deep we are at a certain point. Using multiple nested directives inside elements with an ng-controller directive could have lead to something like this when using the old way of referencing scopes. And no one really wants to do that all day!
<textarea ng-model="$parent.$parent.$parent.$parent.myText"></textarea>

Bind the textarea to a scope variable's property rather than directly to a scope variable:
controller:
$scope.notice = {text: ""}
template:
<textarea ng-model="notice.text"></textarea>

It is, indeed, ui-if that creates the problem. Angular if directives destroy and recreate portions of the dom tree based on the expression. This is was creates the new scope and not the textarea directive as marandus suggested.
Here's a post on the differences between ngIf and ngShow that describes this well—what is the difference between ng-if and ng-show/ng-hide.

using ng-repeat with directives causes child directives not to update

so if found this very interesting bug in angular.js. if you have a custom directive inside a ng-repeat that is actively changing the variables in the directive don't update. meaning if i have 3 elements in my array for ng-repeat it initializes just fine but if i delete element 1 from the array any variables that element 1 had passed to its child directive somehow end up in element 2's child directive here is my example code.
<div ng-app='testing'>
<div ng-controller='testing as test'>
<div ng-repeat='item in test.example track by $index'>
{{item.title}}
<child scope='item.data'></child>
<button ng-click="test.delete($index)">
Delete
</button>
</div>
</div>
</div>
then in my js file
console.log('hello world');
var app=angular.module('testing',['testingChild']);
app.controller('testing',[function(){
this.example=[{
title:"this is the first title",
data:"this is the first index"
},{
title:"this is the second title",
data:"this is the second index"
},{
title:"this is the third title",
data:"this is the third index"
}];
this.delete=function(index){
this.example.splice(index,1);
};
}]);
var child=angular.module('testingChild',[]);
child.directive('child',[function(){
return{
restrict:"E",
scope:{
parent:"=scope"
},
template:"<div>{{child.parent}}</div>",
controller:['$scope',function($scope){
this.parent=$scope.parent;
}],
controllerAs:"child"
};
}]);
and i have a functioning jsfiddle here. all you have to do to see it work is delete one of the first elements. does anyone know what causes this and how to fix it?
Side note:
I thought it might be useful also to mention that when using this in a slighty different situation with editable elements in the child (like a text box) the data binding worked from the child to the parent. so assigning a variable attached to the controller to the scoped variable from the parent worked in that direction. this seems to be the only situation i have come across where it would be from the parent to the child and that is what is not working.

Change:
template:"<div>{{child.parent}}</div>",
controller:['$scope',function($scope){ this.parent=$scope.parent; }]
To:
template:"<div>{{parent}}</div>"
controller:function(){ }
since you are using controllerAs syntax, you dont need the $scope injection.
For the binding work as expected, you dont use child.parent, only parent (or whatever you inject in the this context on your controller

I found a property in the $compile service that fixes this problem. adding the attribute bindToController:true to the directive takes all of the variables defined in your scope attribute and attaches them to the controller rather then the scope itself meaning the 2 way data binding is to the variable on the controller rather then the variable on the scope. so the end result has these changes
in your directive definition
scope:{
parent:"=scope"
},
bindToController:true,
and in the controller remove the this.parent=$scope.parent
here is an updated jsfiddle

Bindonce on ngRepeat

What is the effect of using the native bindonce on an ng-repeat object? For example:
ng-repeat="data in ::stuff"
Does this mean every item in 'stuff' has the watcher removed? Or do you still need to apply bindonce to every child bind in the repeat like this?
<div ng-repeat="data in ::stuff">
<span ng-bind="::data.thing"></span>
</div>

For data in ::stuff, the array is bound once and a $watcher is not created after bound the first time, and therefore any changes to that array will not update your ng-repeat's view.
However, unless you have ::data.thing changes to individual objects will still be registered. Those watchers belong to the object itself and not the shallow contents of the array.
See my plunkr below.
<iframe src="http://embed.plnkr.co/3gbmI2kqd3rT7z0GEyK7/"></iframe>

AngularJs Avoiding Scoping Issues

I recently spent over 4 hours before figuring out why my ng-model directive used in combination with ng-options was not correctly binding to the property within my controller. The <select> element was being properly initialized - receiving a value from the controller (parent) scope. But the child scope was not correctly updating the parent scope. After checking out the following questions and plunkers, I was able to develop a "work around" for this issue:
Helpful stackoverflow question 1
Helpful stackoverflow question 2
Basic Plunker
I found that the property I was binding to in my <select> element was binding to a property of the same name within a child scope of the controller - therefore not the value was not reflected as expected in the controller's scope. After changing
<select ng-options="asset as asset.Name for asset in allAssets" ng-model="selectedAsset" ng-change="lookupAssetPermissions()"></select>
to
<select ng-options="asset as asset.Name for asset in allAssets" ng-model="$parent.selectedAsset" ng-change="lookupAssetPermissions()"></select>
The value in selectedAsset was correctly binding to the property in the controller's scope (as seen in the ng-change event handler). The entire context of my element is the following:
<!---outer div has controller level scope----->
<div>
<!---inner div creates child scope with ng-if----->
<div ng-if="true condition here">
<!---select statement from above----->
<select ng-model="$parent.selectedAsset">...</select>
</div>
</div>
Do I have any other options in this scenario other than purposefully binding to the parent scope? If I had multiple child scopes (nested ng-if statements), would I need to alter the ng-model to bind to $parent.$parent.$parent....selectedAsset in order to update the value in my controllers scope? Are there any "best practices" on this topic?

Put all variables inside some object i.e.:
$scope.Model = {
selectedAsset : 'mySelectedAsset1',
selectedAsset2 : 'mySelectedAsset2',
selectedAsset3 : 'mySelectedAsset3'
}
Then you can:
<div ng-repeat> //new scope
<div ng-repeat> // new scope
<input ng-model="Model.selectedAsset">
This also lows your 'dependency' on $scope, defining such Model object will show everyone who is reading your code what model u have.

AngularJS does not refresh ng-show when using only attributes

I have an AngularJS app, and just noticed that if I use ng-show and ng-click together and don't use function on the controller, then the ng-show is not working as expected.
So I have this:
<div ng-app ng-controller="Controller">
<div ng-repeat="d in data">
<button ng-show="showEdit!==d" ng-click="showEdit=d">{{d}}</button>
</div>
</div>
With a controller:
function Controller($scope){
$scope.data=[1,2,3]
}
Fiddle: http://jsfiddle.net/sashee/v6XrK/
And the buttons are disappearing when I click them, and never reappear.
If I change the view to this:
<div ng-app ng-controller="Controller">
<div ng-repeat="d in data">
<button ng-show="showEdit!==d" ng-click="show(d)">{{d}}</button>
</div>
</div>
And the controller:
function Controller($scope){
$scope.data=[1,2,3]
$scope.show=function(d){
$scope.showEdit=d;
}
}
Fiddle: http://jsfiddle.net/sashee/UFGv4/
Everything works as expected. I think both versions should do exactly the same, but they aren't. What could be the difference or the explanation?

Simple, ng-repeat creates it's own scope, so when you do showEdit=d inside your ng-repeat -- showEdit is limited to the scope of the current repeater. Your variable gets set and your button disappears.
In the example where you call the function, you have a variable $scope.showEdit -- well that variable isn't limited to the repeat scope, so you will always have two buttons showing since showEdit is being assigned differently due to each click.

Please use spaces in your angular expressions.
The difference is that your ng-show and ng-click are in an ng-repeat. Each ng-repeat element has its own scope. So when you do the following:
ng-click="showEdit=d"
You are creating a new value of showEdit on the anonymous ng-repeat scope, not the scope that your controller knows about. Other ng-repeat elements know nothing about it, so your conditional ng-show="showEdit!==d" reflects the value that you just set, not the value of showEdit from your controller.

Well, it's a bit quirky.
ng-repeat creates a new scope for each iterated element.
When you bind the click expression showEdit=d, you actually bind this expression to the Nth scope, created by the ng-repeat (hence the showEdit is located in scopeN).
When you simply use the function from the Controller, you change the showEdit field of the Controller's scope!
- Controller scope (showEdit in the 2nd example)
- scope 1 (showEdit 1 in the 1st example)
- scope 2 (showEdit 2 in the 1st example)
...
- scope N (showEdit N in the 1st example)