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

Question

I have a few checkboxes:

Answer 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.

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With a simple array as input data

The HTML could look like:

   {{fruitName}}

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

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With an object array as input data

The HTML could look like:

  
   {{fruit.name}}

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

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