AngularJS Passing Scope? - javascript

I'm actually not sure what the title of the question should be, as it's not clear to me what I am missing.
I have boiled this down to a very simple example (the actual case is more complex). I have a text box and button inside of an ng-switch. The switch, I've read, creates it's own local scope.
What I want to do pass the value of the text box to a function when the button is clicked. In the function, I will do what needs to be done with the value, then clear the text box. I'm struggling to find the right way to do this.
Controller Code:
$scope.temp = 1;
$scope.tempCall = function (tempModel) {
tempModel = ""; //this doesn't work
$scope.tempModel = ""; //nor does this
};
HTML/Template:
<div ng-switch on="temp">
<div ng-switch-when="1">
<input ng-model="tempModel" />
<input type="button" ng-click="tempCall(tempModel)" />
</div>
<div ng-switch-when="2">TWO</div>
</div>
I believe I can actually traverse the scope from the parent or root scope and clear the value, but that doesn't "feel" correct. What is the correct (Angular) way to clear this value?

When you are working with primitive values in angular scopes, you cannot overwrite a value in a parent scope from a child scope. This is because angular uses javascript prototypal inheritance.
What you could do in this case is create an object in the parent scope, then you can update the values on that in the child scope. Because you are not overwriting the object (only properties attached to it) the references work.
I created a demo of this on plunk you can view it here
$scope.temp = 1;
$scope.tempModel = {};
$scope.tempCall = function () {
$scope.tempModel.previous = $scope.tempModel.value
$scope.tempModel.value = "";
};
<div ng-switch on="temp">
<div ng-switch-when="1">
<input ng-model="tempModel.value" />
<input type="button" ng-click="tempCall()" />
{{tempModel.previous}}
</div>
<div ng-switch-when="2">TWO</div>

Here's one way to do it:
<input type="button" ng-click="tempCall(tempModel);tempModel='';" />
Probably the more "Angular way" would be to use a dot in your model like:
<input type="text" ng-model="tempModel.value" />
Then call your function by passing the tempModel object like:
<input type="button" ng-click="tempCall(tempModel)" />
Then you will be able to clear the value with:
$scope.tempCall = function (tempModel) {
tempModel.value = "";
};
Here is a fiddle
To prevent databinding issues, "the rule of thumb is, if you use ng-model there has to be a dot somewhere." Miško Hevery

Related

AngularJS passing data to Javascript variables and opposite

I am looking for a solution on passing data from a specific input text field to AngularJS. it may be a Javascript variable too. If the variable is changed from inside a javascript code it is not updating on AngularJS side. If i take the same variable and in the text field add at least one character or modify something i see variable updating and everything working as it should.
I tried something with angular.element(document.getElementById('ControllerElementID')).scope().funct(); but still no luck. When i update at least one field from the keyboard, all text fields that are related to "ng-model="sig.sigBase6422"" are updating properly as it should. If i call this updates through a JavaScript function i see updates only on specific text field and no updates at all on ng-model happening. How to make it updating as simple as possible? Below i will post a small example. I was able to store data from variable to a external file and in AngularJS read it from file and use it. this is way too long, complicated and ridiculous. I am sure there should be a better way.
Thank you!
<script type="text/javascript">
function addtext1() {document.getElementById("myID1").value = "1111111111111111";}
function addtext2() {document.getElementById("myID2").value = "2222222222222222";}
</script>
<div>
<form action="#" name="FORM1">
<TEXTAREA NAME="sigData" ng-model="sig.sigBase6422" ROWS="10" COLS="20">String: </TEXTAREA>
</form><br>
<input type="text" name="myID1" id="myID1" ng-model="sig.sigBase6422" ><br>
<input type="text" name="myID2" id="myID2" ng-model="sig.sigBase6422" ><br>
<p>Value {{sig.sigBase6422}}!</p>
</div>
<!-- test field -->
Add text 1
Add text 2
Indeed if you want to use AngularJS for what it was created, you have to rewrite your code completely using directive or controller. You variables and functions accessible from the view should be attached to the $scope too.
var myApp = angular.module("myApp", []);
myApp.controller("myCtrl", function($scope){
$scope.addtext1 = function () {
$scope.sig.sigBase6422 += "1111111111111111";
};
$scope.addtext2 = function () {
$scope.sig.sigBase6422 += "2222222222222222";
};
$scope.sig = {
sigBase6422: ""
};
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<div ng-app="myApp" ng-controller="myCtrl">
<form action="#" name="FORM1">
<TEXTAREA ng-model="sig.sigBase6422" ROWS="10" COLS="20">String: </TEXTAREA>
</form><br/>
<input type="text" name="myID1" id="myID1" ng-model="sig.sigBase6422" /><br/>
<input type="text" name="myID2" id="myID2" ng-model="sig.sigBase6422" /><br/>
<p>Value {{sig.sigBase6422}}!</p>
<!-- test field -->
<button ng-click="addtext1()">Add text 1</button>
<button ng-click="addtext2()">Add text 2</button>
</div>
You seem to have misunderstood how angular works. What you're trying to do is not how angular works. What you're trying to do with native JavaScript can be done with angular. Angular can update dom and Dom updates angular as it's responsible for causing updates.... anyway without getting any deeper. You need to read more on how angular works and try sticl within the bounds of angular instead of mixing.
That being said :
Tigger change on the Dom element after you have updated its value. Or better yet get access to scope variable on the Dom and call a function in angular with the value you're and set they value from inside of a angular.
Use this code while updating the value.
pick the controller first using
var scope = angular.element(document.getElementById('yourControllerElementID')).scope();
scope.<variablename> = <your operation>;
then
scope.$apply();
the remaining thing will be taken care by Angular.

Disabling submit button based on fields added with ng-bind-html

JSFiddle here: http://jsfiddle.net/c6tzj6Lf/4/
I am dynamically creating forms and buttons and want to disable the buttons if the required form inputs are not completed.
HTML:
<div ng-app="choicesApp">
<ng-form name="choicesForm" ng-controller="ChoicesCtrl">
<div ng-bind-html="trustCustom()"></div>
<button ng-repeat="button in buttons" ng-disabled="choicesForm.$invalid">
{{button.text}}
</button>
</ng-form>
</div>
JavaScript:
angular.module('choicesApp', ['ngSanitize'])
.controller('ChoicesCtrl', ['$scope', '$sce', function($scope, $sce) {
$scope.custom = "Required Input: <input required type='text'>";
$scope.trustCustom = function() {
return $sce.trustAsHtml($scope.custom);
};
$scope.buttons = [
{text:'Submit 1'},
{text:'Submit 2'}];
}]);
choicesForm.$invalid is false and does not change when entering text into the input field.
Solution:
I ended up using the angular-bind-html-compile directive from here: https://github.com/incuna/angular-bind-html-compile
Here is the relevant bit of working code:
<ng-form name="choicesForm">
<div ng-if="choices" bind-html-compile="choices"></div>
<button ng-click="submitForm()" ng-disabled="choicesForm.$invalid">
Submit
</button>
</ng-form>
And choices might be a snippit of HTML like this:
<div><strong>What is your sex?</strong></div>
<div>
<input type="radio" name="gender" ng-model="gender" value="female" required>
<label for="female"> Female</label><br>
<input type="radio" name="gender" ng-model="gender" value="male" required>
<label for="male"> Male</label>
</div>
The main problem is that ngBindHtml doesn't compile the html - it inserts the html as it is. You can even inspect the dynamic input and see that it doesn't have the ngModel's CSS classes (ng-pristine, ng-untouched, etc) which is a major red flag.
In your case, the form simply doesn't know that you've added another input or anything has changed for that matter. Its state ($pristine, $valid, etc) isn't determined by its HTML but by the registered NgModelControllers. These controllers are added automatically when an ngModel is linked.
For example this <input required type='text'> won't affect the form's validity, even if it's required, since it doesn't have ngModel assigned to it.
But this <div ng-model="myDiv" required></div> will affect it since it's required and has ngModel assigned to it.
The ngDisabled directive on your buttons works as expected since it depends on the form's $invalid property.
See this fiddle which showcases how ngModel registers its controller. Note that the html containing the dynamic input gets compiled after 750ms just to show how NgModelControllers can be added after FormController has been instantiated.
There are a few solutions in your case:
use a custom directive to bind and compile html - like this one
use ngInclude which does compile the html
use $compile to compile the newly added HTML but this is a bit tricky as you won't know exactly when to perform this action
This is an answer yet imcomplete because i cannot do the code at the moment.
I think your html will be included, not compiled. So the inputs are not bind to angular and are not part of the angular form object.
The only way i see is to use a directive that will compile the passed html and add it to your form. This may be quite tricky though, if you want to go on this way i suggest to edit your question to ask for the said directive.
However i'm not really familiar with $compile so i don't know if it'll work to just add $compile around $sce.trustAsHtml()
You can write a method as ng-disabled does not work with booleans, it works with 'checked' string instead:
So on your controller place a method :
$scope.buttonDisabled = function(invalid){
return invalid ? "checked" : "";
};
And on your view use it on angular expression :
<button ng-repeat="button in buttons" ng-disabled="buttonDisabled(choicesForm.$invalid)">
Here is a working fiddle
Working DEMO
This is the solution you are looking for. You need a custom directive. In my example I have used a directive named compile-template and incorporated it in div element.
<div ng-bind-html="trustCustom()" compile-template></div>
Directive Code:
.directive('compileTemplate', function($compile, $parse){
return {
link: function(scope, element, attr){
var parsed = $parse(attr.ngBindHtml);
function getStringValue() { return (parsed(scope) || '').toString(); }
//Recompile if the template changes
scope.$watch(getStringValue, function() {
$compile(element, null, -9999)(scope); //The -9999 makes it skip directives so that we do not recompile ourselves
});
}
}
});
I found the directive in this fiddle.
I believe what is really happening though due to jsfiddle I'm unable to dissect the actual scopes being created here.
<div ng-app="choicesApp">
<ng-form name="choicesForm" ng-controller="ChoicesCtrl">
<div ng-bind-html="trustCustom()"></div>
<button ng-repeat="button in buttons" ng-disabled="choicesForm.$invalid">
{{button.text}}
</button>
</ng-form>
</div>
The first div is your top level scope, your form is the first child scope. Adding the div using a function creates the dynamically added input field as a child of the first child, a grandchild of the top level scope. Therefore your form is not aware of the elements you're adding dynamically causing only the static field to be required for valid form entry.
A better solution would be to use ng-inclue for additional form fields or if your form isn't to large then simply put them on the page or template you're using.

Clear input field

I'm trying to clear ng-model inputs, but is not working, and i can't figure out why.
I have:
<button ng-click="$ctrl.clear()"></button>
and in the clear action i have:
$scope.$event = null;
Should work, right?
If i do:
<button ng-click="$event = null"></button>
Will work, but i want avoid this in the HTML.
I already try to use angular.copy, and:
$scope.$event = {};
$scope.$event = '';
But doesn't work and is not giving me any erros message.
Thanks.
UPDATE:
<input type="text" ng-model="$event.title"/>
<input type="text" ng-model="$event.name"/>
<input type="number" ng-model="$event.age"/>
<input type="date" ng-model="$event.date"/>
The problem is in the click handler, $event refers to the event object not your event object in the scope.
Use another name to refer your object. Note that property names starting with $ is normally used by angularjs to refer to its properties, so best we don't use them.

Angular Databinding doesnt Work

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;
}]);

ng-click doesn't take parameters from the DOM

I have the following code:
<input id="id">
<button data-action="bea" ng-click="Create($('#id1')[0].value);" class="btn">Insert ID</button>
<button data-action="bea" ng-click="Create($('#id2')[0].value);" class="btn">Insert ID</button>
In the JS I have:
$scope.Create = function (id){
if (id === undefined) {
$scope.data = "You must specify an id";
} else {
$scope.data = data;
console.log(data);
});
}
};
When the call gets into the Create function the value of the id is undefined.
If I add the following line at the beginging of the Create function everything works ok:
id = $('#id')[0].value;
If I send a constant value it works:
<button data-action="bea" ng-click="Create('SomeID');" class="btn">Insert ID</button>
Why is this happening and how can I do that without putting the line of value into the method?
Thanks
This is just an extension of comments and other answers, You could achieve this in many ways using angular, one simple example could be:-
<!-- Add a controller -->
<div ng-controller="MainCtrl">
<!-- Give a model binding to your text input -->
<input ng-model="userEntry" type="text"/>
<!-- ng-click pass which ever argument you need to pass, provided it is an expression that can be evaluated against the scope or any constants -->
<button data-action="bea" ng-click="Create(userEntry);" class="btn">Insert ID</button>
<!-- Some simple data binding using interpolation -->
{{data}}
<!-- Just for demo on repeater on a list of items on the scope -->
<div ng-repeat="item in items track by $index">{{item}}</div>
</div>
Example Demo
My 2 cents on the lines of what were originally trying to do:-
Use angular bindings instead of accessing DOM directly for getting the data, it really helps you deal with just the data without worrying about how to access or render it in DOM. If you think you need to access DOM for implementing business logic re-think on the design, if you really need to do it, do it in a directive. Angular is very opinionated on the design and when where you do DOM access.
ng-model
ng-binding
controller
all about ngmodel controller
This is not the way you should do in AngularJS. You should really think in Angular if you want to use AngularJS. Refer this post ("Thinking in AngularJS" if I have a jQuery background?)
All DOM manipulation should be done in Directive. Refer this page that I found really clear.
(http://ng-learn.org/2014/01/Dom-Manipulations/)
My guess is that $ is not bound to the jQuery function when the ng-click value is evaluated, because it is not exposed in the Angular scope.
Solutions to adress this:
expose the jQuery function in scope somewhere, e.g $scope.$ = $; in a controller.
make the Create function parameterless as you suggested, with a var id = $('#id')[0].value; at the beginning
my favorite : avoid using jQuery. If you put some data in the #id element, there's probably a more natural and AngularJS-idiomatic way of retrieving it than querying the DOM (e.g an Angular service).
In particular, if the element you're targeting is an <input> element, then use the ngModel directive to link the value to a $scopeproperty that will be accessible in the controller :
<input ng-model="inputData"/>
The JavaScript you are trying to pass as a parameter of the create function is not available in the scope of the Create function.
Try to target the element a different way.
Does that help?

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