How do I bind to list of checkbox values with AngularJS?

Solution 1:

There are two ways to approach this problem. Either use a simple array or an array of objects. Each solution has it pros and cons. Below you'll find one for each case.

With a simple array as input data

The HTML could look like:

<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>

And the appropriate controller code would be:

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);

    // Is currently selected
    if (idx > -1) {
      $scope.selection.splice(idx, 1);
    }

    // Is newly selected
    else {
      $scope.selection.push(fruitName);
    }
  };
}]);

Pros: Simple data structure and toggling by name is easy to handle

Cons: Add/remove is cumbersome as two lists (the input and selection) have to be managed

With an object array as input data

The HTML could look like:

<label ng-repeat="fruit in fruits">
  <!--
    - Use `value="{{fruit.name}}"` to give the input a real value, in case the form gets submitted
      traditionally

    - Use `ng-checked="fruit.selected"` to have the checkbox checked based on some angular expression
      (no two-way-data-binding)

    - Use `ng-model="fruit.selected"` to utilize two-way-data-binding. Note that `.selected`
      is arbitrary. The property name could be anything and will be created on the object if not present.
  -->
  <input
    type="checkbox"
    name="selectedFruits[]"
    value="{{fruit.name}}"
    ng-model="fruit.selected"
  > {{fruit.name}}
</label>

And the appropriate controller code would be:

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 });
  };

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

Pros: Add/remove is very easy

Cons: Somewhat more complex data structure and toggling by name is cumbersome or requires a helper method

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

Solution 2:

A simple solution:

<div ng-controller="MainCtrl">
  <label ng-repeat="(color,enabled) in colors">
      <input type="checkbox" ng-model="colors[color]" /> {{color}} 
  </label>
  <p>colors: {{colors}}</p>
</div>

<script>
  var app = angular.module('plunker', []);

  app.controller('MainCtrl', function($scope){
      $scope.colors = {Blue: true, Orange: true};
  });
</script>

http://plnkr.co/edit/U4VD61?p=preview

Solution 3:

<input type='checkbox' ng-repeat="fruit in fruits"
  ng-checked="checkedFruits.indexOf(fruit) != -1" ng-click="toggleCheck(fruit)">

.

function SomeCtrl ($scope) {
    $scope.fruits = ["apple, orange, pear, naartjie"];
    $scope.checkedFruits = [];
    $scope.toggleCheck = function (fruit) {
        if ($scope.checkedFruits.indexOf(fruit) === -1) {
            $scope.checkedFruits.push(fruit);
        } else {
            $scope.checkedFruits.splice($scope.checkedFruits.indexOf(fruit), 1);
        }
    };
}