How to Bind AngularJS Checkboxes to a List of Values?

Binding AngularJS Checkboxes to List of Values

Problem:

In AngularJS, a list of checkboxes is presented, and the objective is to establish a binding between them and a list in the controller. Each checked checkbox indicates the inclusion of its associated value in the list.

Solution:

AngularJS provides two viable solutions to this problem:

1. Simple Array as Input Data

In this approach, the HTML structure mimics the checkbox list:

<label ng-repeat="fruitName in fruits">
  <input
    type="checkbox"
    name="selectedFruits[]"
    value="{{fruitName}}"
    ng-checked="selection.indexOf(fruitName) > -1"
    ng-click="toggleSelection(fruitName)"
  > {{fruitName}}
</label>

The accompanying controller code handles the interaction:

app.controller('SimpleArrayCtrl', ['$scope', function SimpleArrayCtrl($scope) {

  // Fruits
  $scope.fruits = ['apple', 'orange', 'pear', 'naartjie'];

  // Selected fruits
  $scope.selection = ['apple', 'pear'];

  // Toggle selection for a given fruit by name
  $scope.toggleSelection = function toggleSelection(fruitName) {
    var idx = $scope.selection.indexOf(fruitName);

    if (idx > -1) {
      $scope.selection.splice(idx, 1);
    } else {
      $scope.selection.push(fruitName);
    }
  };
}]);

2. Object Array as Input Data

Using an object array as the input data adds additional complexity but simplifies insertion and deletion operations:

<label ng-repeat="fruit in fruits">
  <input
    type="checkbox"
    name="selectedFruits[]"
    value="{{fruit.name}}"
    ng-model="fruit.selected"
  > {{fruit.name}}
</label>

The controller code reflects the change:

app.controller('ObjectArrayCtrl', ['$scope', 'filterFilter', function ObjectArrayCtrl($scope, filterFilter) {

  // Fruits
  $scope.fruits = [
    { name: 'apple',    selected: true },
    { name: 'orange',   selected: false },
    { name: 'pear',     selected: true },
    { name: 'naartjie', selected: false }
  ];

  // Selected fruits
  $scope.selection = [];

  // Helper method to get selected fruits
  $scope.selectedFruits = function selectedFruits() {
    return filterFilter($scope.fruits, { selected: true });
  };

  $scope.$watch('fruits|filter:{selected:true}', function (nv) {
    $scope.selection = nv.map(function (fruit) {
      return fruit.name;
    });
  }, true);
}]);

Advantages and Disadvantages:

• Simple Array:

  • Easy data structure
  • Easy toggling by name
  • However, cumbersome insertion and deletion

• Object Array:

  • More complex data structure
  • Toggles by name require helper methods
  • However, insertion and deletion are very simple

Demo: http://jsbin.com/ImAqUC/1/

The above is the detailed content of How to Bind AngularJS Checkboxes to a List of Values?. For more information, please follow other related articles on the PHP Chinese website!