AngularJS: ng-model not binding to ng-checked for checkboxes

Question 1

ngModel and ngChecked are not meant to be used together.

ngChecked is expecting an expression, so by saying ng-checked="true", you're basically saying that the checkbox will always be checked by default.

You should be able to just use ngModel, tied to a boolean property on your model. If you want something else, then you either need to use ngTrueValue and ngFalseValue (which only support strings right now), or write your own directive.

What is it exactly that you're trying to do? If you just want the first checkbox to be checked by default, you should change your model -- item1: true,.

Edit: You don't have to submit your form to debug the current state of the model, btw, you can just dump {{testModel}} into your HTML (or <pre>{{testModel|json}}</pre>). Also your ngModel attributes can be simplified to ng-model="testModel.item1".

http://plnkr.co/edit/HtdOok8aieBjT5GFZOb3?p=preview

Question 2

You can use ng-value-true to tell angular that your ng-model is a string.

I could only get ng-true-value working if I added the extra quotes like so (as shown in the official Angular docs - https://docs.angularjs.org/api/ng/input/input%5Bcheckbox%5D)

ng-true-value="'1'"

Question 3

What you could do is use ng-repeat passing in the value of whatever you're iterating on to the ng-checked and from there utilising ng-class to apply your styles depending on the result.

I did something similar recently and it worked for me.

Question 4

Can Declare As the in ng-init also getting true

<!doctype html>
<html ng-app="plunker" >
  <head>
    <meta charset="utf-8">
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css">
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.js"></script>
    <script src="app.js"></script>
  </head>
  <body ng-controller="MainCtrl" ng-init="testModel['item1']= true">
    <label><input type="checkbox" name="test" ng-model="testModel['item1']"  /> Testing</label><br />
    <label><input type="checkbox" name="test" ng-model="testModel['item2']" /> Testing 2</label><br />
    <label><input type="checkbox" name="test" ng-model="testModel['item3']" /> Testing 3</label><br />
    <input type="button" ng-click="submit()" value="Submit" />
  </body>
</html>

And You Can Select the First One and Object Also Shown here true,false,flase

Question 5

The `ng-model` and `ng-checked` directives should not be used together

From the Docs:

ngChecked

Sets the checked attribute on the element, if the expression inside ngChecked is truthy.

Note that this directive should not be used together with ngModel, as this can lead to unexpected behavior.

— AngularJS ng-checked Directive API Reference

Instead set the desired initial value from the controller:

<input type="checkbox" name="test" ng-model="testModel['item1']" ̶n̶g̶-̶c̶h̶e̶c̶k̶e̶d̶=̶"̶t̶r̶u̶e̶"̶ />
    Testing<br />
<input type="checkbox" name="test" ng-model="testModel['item2']" /> Testing 2<br />
<input type="checkbox" name="test" ng-model="testModel['item3']" /> Testing 3<br />
<input type="button" ng-click="submit()" value="Submit" />

$scope.testModel = { item1: true };

Question 6

You don't need ng-checked when you use ng-model. If you're performing CRUD on your HTML Form, just create a model for CREATE mode that is consistent with your EDIT mode during the data-binding:

CREATE Mode: Model with default values only

$scope.dataModel = {
   isItemSelected: true,
   isApproved: true,
   somethingElse: "Your default value"
}

EDIT Mode: Model from database

$scope.dataModel = getFromDatabaseWithSameStructure()

Then whether EDIT or CREATE mode, you can consistently make use of your ng-model to sync with your database.

Question 7

I had this issue while i am working with the angular js migration from 1.2 to 1.3. The input type checkbox was not triggered if it was initiated from controller as well as the ng change event also not triggered. I tried with all types since ng model along with ng checked wont work. Then ended with simple thing it worked for me like removing the ng change event by replacing with ng click.

AngularJS: ng-model not binding to ng-checked for checkboxes

The ng-model and ng-checked directives should not be used together

ngChecked

CREATE Mode: Model with default values only

EDIT Mode: Model from database

The `ng-model` and `ng-checked` directives should not be used together