javascript - 如何使用 AngularJS 绑定(bind)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">

我想绑定(bind)到我的 Controller 中的一个列表，这样每当一个复选框被更改时， Controller 都会维护一个所有选中值的列表，例如 ['apple', 'pear'].

ng-model 似乎只能将单个复选框的值绑定(bind)到 Controller 中的变量。

还有其他方法可以将四个复选框绑定(bind)到 Controller 中的列表吗？

Answer 1

有两种方法可以解决这个问题。使用简单数组或对象数组。每个解决方案都有其优点和缺点。您可以在下面找到每种情况下的一个。

---

以简单数组作为输入数据

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 Controller 代码是:

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);
    }
  };
}]);

优点:简单的数据结构和按名称切换很容易处理

缺点:添加/删除很麻烦，因为必须管理两个列表(输入和选择)

---

以对象数组作为输入数据

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 Controller 代码是:

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/删除非常简单

缺点:更复杂的数据结构和按名称切换很麻烦或需要辅助方法

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演示:http://jsbin.com/ImAqUC/1/