AngularJS: ng-model binding to ng-checked for checkboxes

AngularJS: ng-model binding to ng-checked for checkboxes

In AngularJS, when you want to bind a checkbox's ng-model to its ng-checked directive, you need to understand how each directive works and interacts with the checkbox element.

Understanding ng-model and ng-checked

  • ng-model: Binds the checkbox to a property in your AngularJS controller. It reflects the checkbox's state (checked or unchecked) based on the value of the bound property.

  • ng-checked: Evaluates an expression and sets the checked state of the checkbox accordingly. It does not bind any value back to the scope; it only controls the visual state of the checkbox.

Scenario

If you want to bind a checkbox's checked state to a property in your controller, you typically use ng-model. However, in some cases, you may want to conditionally set the checkbox's checked state based on a dynamic condition evaluated in ng-checked.

Example

Let's say you have an array of items in your controller and you want to mark checkboxes as checked based on a condition for each item.

Controller

// controller.js angular.module('myApp', []) .controller('myController', function($scope) { $scope.items = [ { id: 1, name: 'Item 1', selected: true }, { id: 2, name: 'Item 2', selected: false }, { id: 3, name: 'Item 3', selected: true } ]; });

HTML Template

<!-- index.html --> <div ng-app="myApp" ng-controller="myController"> <ul> <li ng-repeat="item in items"> <label> <input type="checkbox" ng-model="item.selected" ng-checked="item.selected"> {{ item.name }} </label> </li> </ul> </div>

Explanation

  • ng-repeat: Iterates over each item in the items array.
  • ng-model: Binds each checkbox to the selected property of the respective item in the items array. This establishes a two-way binding between the checkbox state and the selected property.
  • ng-checked: Sets the initial checked state of the checkbox based on the value of item.selected. While ng-model handles the binding, ng-checked ensures that the initial state is correctly reflected visually.

Key Points

  • Two-way Binding: Use ng-model when you want two-way binding between the checkbox state and a model property.
  • Conditional Checked State: Use ng-checked when you want to conditionally set the checked state of the checkbox based on a dynamic condition or expression.

By combining ng-model and ng-checked appropriately, you can create dynamic and interactive checkbox behaviors in your AngularJS application, ensuring that the UI reflects the state of your data model accurately.

Examples

  1. Using ng-model with ng-checked to bind checkbox state in AngularJS

    • Description: Utilize ng-model and ng-checked directives together to bind checkbox state to a model in AngularJS.
    • Code:
      <input type="checkbox" ng-model="isChecked" ng-checked="isChecked">

  2. Toggle checkbox checked state using ng-model and ng-checked in AngularJS

    • Description: Implement toggling of checkbox checked state using ng-model and ng-checked directives in AngularJS.
    • Code:
      <input type="checkbox" ng-model="isChecked" ng-checked="isChecked">

  3. Binding checkbox state to ng-model using ng-checked in AngularJS controller

    • Description: Bind checkbox state to a model property defined in the AngularJS controller using ng-checked.
    • Code:
      <input type="checkbox" ng-model="isChecked" ng-checked="isChecked">

  4. AngularJS ng-checked directive not updating ng-model

    • Description: Resolve issues where the ng-model state does not update when using ng-checked directive in AngularJS.
    • Code:
      <input type="checkbox" ng-model="isChecked" ng-checked="isChecked">

  5. AngularJS checkbox binding with ng-checked in ng-repeat

    • Description: Bind checkboxes in an ng-repeat directive using ng-checked to manage state in AngularJS.
    • Code:
      <div ng-repeat="item in items"> <input type="checkbox" ng-model="item.isChecked" ng-checked="item.isChecked"> </div>

  6. AngularJS checkbox checked state controlled by ng-model

    • Description: Control checkbox checked state exclusively using ng-model directive in AngularJS.
    • Code:
      <input type="checkbox" ng-model="isChecked">

  7. AngularJS checkbox checked binding using ng-checked directive

    • Description: Use ng-checked directive to bind checkbox checked state dynamically in AngularJS.
    • Code:
      <input type="checkbox" ng-checked="isChecked">

  8. AngularJS checkbox checked state based on ng-model value

    • Description: Set checkbox checked state based on the value of ng-model in AngularJS.
    • Code:
      <input type="checkbox" ng-model="isChecked" ng-checked="isChecked">

  9. AngularJS checkbox checked state and ng-model synchronization

    • Description: Ensure synchronization between checkbox checked state and ng-model in AngularJS using ng-checked.
    • Code:
      <input type="checkbox" ng-model="isChecked" ng-checked="isChecked">

  10. AngularJS checkbox checked state not reflecting ng-model changes

    • Description: Troubleshoot scenarios where checkbox checked state does not reflect changes in ng-model using ng-checked in AngularJS.
    • Code:
      <input type="checkbox" ng-model="isChecked" ng-checked="isChecked">

More Tags

android-wifi iconv convolution datepicker static spring-cloud-feign webautomation microsoft-graph-api string-concatenation operation

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