如何使用AngularJS绑定到复选框值列表？ [英] How do I bind to list of checkbox values with AngularJS?

问题描述

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">

我想绑定到控制器中的列表，这样每当复选框被更改时控制器维护所有选中值的列表，例如 ['apple'，'pear'] 。

That I would like to bind to a list in my controller such that whenever a checkbox is changed the controller maintains a list of all the checked values, for example, ['apple', 'pear'].

ng-model似乎只能将一个复选框的值绑定到控制器中的变量。

ng-model seems to only be able to bind the value of one single checkbox to a variable in the controller.

还有另一种方法可以做到这一点我可以绑定控制器中列表的四个复选框？

Is there another way to do it so that I can bind the four checkboxes to a list in the controller?

推荐答案

有两种方法可以解决这个问题。使用简单数组或对象数组。每种解决方案都有它的优点和缺点。下面你会找到每个案例一个。

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.

HTML可能如下所示：

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>

相应的控制器代码为：

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);
    }
  };
}]);

优点：简单的数据结构和按名称切换很容易处理

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

缺点：添加/删除很麻烦，因为必须管理两个列表（输入和选择）

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

HTML可能如下所示：

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>

相应的控制器代码为：

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/删除非常简单

Pros: Add/remove is very easy

缺点：更复杂的数据结构和按名称切换很麻烦或者需要辅助方法

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

演示： http://jsbin.com / ImAqUC / 1 /

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