我如何用AngularJS绑定到复选框值列表？

Question

我有几个复选框：

<input type='checkbox' value="apple" checked>
<input type='checkbox' value="orange">
<input type='checkbox' value="pear" checked>
<input type='checkbox' value="naartjie">

我希望绑定到控制器中的一个列表，这样，每当更改复选框时，控制器就会维护所有选中值的列表，例如，['apple','pear']。

ng-model似乎只能将一个复选框的值绑定到控制器中的一个变量。

有没有另一种方法可以这样做，以便我可以将四个复选框绑定到控制器中的一个列表？

Answer 1

有两种方法来处理这个问题。使用简单数组或对象数组。每种解决方案都有利弊。下面你会为每个案例找到一个。

HTML可能如下所示：

<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>

适当的控制器代码为：

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);
    }
  };
}]);

缺点：Add/Remove很麻烦，因为必须管理两个列表（输入和选择）

HTML可能如下所示：

<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>

适当的控制器代码为：

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);
}]);

优点：添加/删除非常容易

缺点：数据结构比较复杂，按名称切换比较麻烦，或者需要一个helper方法

演示:http://jsbin.com/imaquc/1/