Cannot get textarea value in angularjs - angularjs

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.

Related

Expose ng-form in scope and reference in ng-init

I am attempting to do something like this:
<div ng-form="testForm" ng-init="$ctrl.doStuffWithForm(testForm)>
Where I define a form/publish the form to the current scope with the name testForm and pass that form object to $ctrl.doStuffWithForm() in the ng-init. However, what appears to be happening is that, at the time of the ng-init, the form creation and/or the creation of testForm in the scope has not happened yet (other testing indicates to me that testForm does point to a form controller at a later point in the Angular lifecycle).
Is there any way for me to pass the form controller to a method in the ng-init like this? Or should I be doing it another way? Is there an attribute similar to ng-init, but that is used later in the lifecycle? What I am trying to do is basically an ng-repeat on an element with an ng-form, and pass each form to a controller method when each element is initialized.
Avoid using $ng-init directive. Simply assign the ng-form to a property of the $ctrl object:
<div ng-form="$ctrl.testForm">
{{$ctrl.testForm.$dirty}}
</div>
I was able to achieve my desired results by putting the ng-init in a child element of the ng-form element:
<div ng-form="testForm">
<div ng-init="$ctrl.doStuffWithForm(testForm)></div>
</div>

Variable value as directive/controller name inside template (with $compile/$interpolate)?

I am creating a directive in which template I need to use the a scope's variable value as the name of the directive (or alternatively controller) to load.
Say I have a directive widget that has a template called widget.html which looks like:
<div class="widget widget.type" {{widget.type}} ng-controller="widget.type">
<div class="navBar">
<div ng-include="widget.type + '-t.html'"></div>
<i class="fa fa-close"></i>
<hr>
</div>
<div ng-include="widget.type + '-f.html'"></div>
</div>
Now widget.type is not getting evaluated in the first line. It works fine for ng-include. Say widget.type's value is weather. The first line should then be interpolated first to look like (doesn't matter if class attribute, widget.type-attr or ng-controller is interpolated)
<div class="widget" weather>
and then compiled to include the weather directive.
How can I get widget.type interpolated in the template?
Not an option is to use ng-include to load the directive. I need to use one common template for the widget and want to add/override/extend the base directive with additonal functionality/Variables.
If this is not the way to achieve that, is there a way to extend a directive the OOP-way?
See the plunkr
You can only place interpolation expressions in text nodes and attribute values. AngularJS evaluates your template by first turning it into DOM and then invoking directive compilation, etc. If you try to place {{...}} instead of attribute name, you'll just end up with messed-up DOM.
If you really need to replace a whole directive based on $scope variable value, you'll need to create a directive for application of other directives and do some heavy lifting with $compile (you'll have to completely re-compile the template each time the value changes). I'd recommend trying to find other designs solving your situation before attempting this.
For adjusting your template based on element attributes, see this answer.

Change value of input placeholder via model?

I'm trying to change the value of the input placeholder from a controller but cant quite figure out how.
input(type='text', ng-model='inputText', side='30', placeholder='enter username')
Is there a way to modify a model's element attributes?
You can bind with a variable in the controller:
<input type="text" ng-model="inputText" placeholder="{{somePlaceholder}}" />
In the controller:
$scope.somePlaceholder = 'abc';
The accepted answer still threw a Javascript error in IE for me (for Angular 1.2 at least). It is a bug but the workaround is to use ngAttr detailed on https://docs.angularjs.org/guide/interpolation
<input type="text" ng-model="inputText" ng-attr-placeholder="{{somePlaceholder}}" />
Issue: https://github.com/angular/angular.js/issues/5025
Since AngularJS does not have directive DOM manipulations as jQuery does, a proper way to modify attributes of one element will be using directive.
Through link function of a directive, you have access to both element and its attributes.
Wrapping you whole input inside one directive, you can still introduce ng-model's methods through controller property.
This method will help to decouple the logic of ngmodel with placeholder from controller.
If there is no logic between them, you can definitely go as Wagner Francisco said.
As Wagner Francisco said, (in JADE)
input(type="text", ng-model="someModel", placeholder="{{someScopeVariable}}")`
And in your controller :
$scope.someScopeVariable = 'somevalue'

ngSwitch slider directive not working

I'm trying to create a slider directive inpired by this example using ngSwitch and ngAnimate but without success. There is a timeout calling the next function that increments the scope.current variable and ngSwitch should use this variable to switch images.
<div class="slider">
<img src="..." />
<img src="..." />
<img src="..." />
</div>
Here is my plunker with the example. I think it is something related with the scope(its always you scope).
UPDATE: I did some progress, I moved the attributes manipulation to the compile function and it seems it helped a bit but now I get an error: No controller: ngSwitch.
new plunker
The reason why Angularjs shows the error No controller: ngSwitch is because ng-switch-when depends on ng-switch. So you should add the attribute of ng-switch-when when the ng-switch scope is created. The easiest way is to use $observe on the ngSwitch.
Here is one way to make the compile work
attrs.$observe('ngSwitch', function () {
for (i = _i = 0, _len = pages.length; _i < _len; i = ++_i) {
page = pages[i];
page.setAttribute('ng-switch-when', i);
}
});
However the animation will not work since you can't access the current value due to the new scope ng-switch created.
In order to make the directive work, I think the easiest way is to declare the ng-switch="current" in the template so the directive can access to the the value it watches on.
Hope it can shed some light on.
I have a workaround using ng-if instead of ng-switch, see here.
If you want to stick around using ng-switch, I would suggest you give a closer look to the scope created by ng-switch (see this).

How to get the NgModelController for input fields inside a ngRepeat directive?

Normally, with a form and input fields, the form controller is published into the related scope under the form name attribute. And, the NgModelController is published under the input name attribute.
So for an input field with an ngModel directive, the NgModelController for the input field can be retrieved like $scope.myFormName.myInputFieldName
The question is how to do the same thing (get the NgModelController) for input fields inside the ngRepeat directive?
I would like to name the input fields using $index as part of the name so each template instance is uniquely named. This renders OK, so
<input name="foo_{{$index}}" ...
renders the instance with $index == 3 to
<input name="foo_3" ...
But trying to get the ngModelController via the published names does not work (it's undefined), e.g.:
$scope.myFormName.foo_3
A plunker showing this is here: http://plnkr.co/edit/jYDhZfgC3Ud0fXUuP7To?p=preview
It shows successfully getting the ngModelController for a 'plain' input element and calling $setValidity, and also shows failing to get the ngModelController for an input element inside an ngRepeat directive.
Copied the relevant section of code from the plunker below:
<div ng-repeat="element in elements">
<div ng-class="{error: form['foo_{{$index}}'].$invalid}">
<input name="foo_{{$index}}" ng-model="element.a" type="number">
<span ng-show="form['foo_{{$index}}'].$error.bar">ngRepeat bar invalid</span>
</div>
</div>
{{form.foo_0.$setValidity('bar', false)}}
#Flek is correct that the new child scopes that ng-repeat creates are the root of the problem here. Since browsers do not allow nesting of <form> elements, ngForm must be used when nesting forms, or when you want to do form validation inside ngRepeat.
See Pawel's answer on the google group thread, which shows how to use ng-form to create inner forms, and/or #blesh's SO answer.
If i understand your question correctly, you are trying to have access to the form elements created inside the ng-repeat.
Please have a look at this fiddle http://jsfiddle.net/EF5Jp/. Inside the button click handler you will have the access to the element with id myForm.foo_2. You can notice that the element is retrieved by myForm.foo_2 and not $scope.myForm.foo_2. Second thing is, changing the value using its scope and not using its value property like angular.element(element).scope().foo = 6;.

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