How do I bind to list of checkbox values with AngularJS?
I have a few checkboxes:
<input type='checkbox' value="apple" checked>
<input type='checkbox' value="orange">
<input type='checkbox' value="pear" checked>
<input type='checkbox' value="naartjie">
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 seems to only be able to bind the value of one single checkbox to a variable in the controller.
Is there another way to do it so that I can bind the four checkboxes to a list in the controller?
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) {
$scope.selection = nv.map(function (fruit) {
return fruit.name;
});
}, true);
}]);
Pros : Add/remove is very easy
Cons : Somewhat more complex data structure and toggling by name is cumbersome or requires a helper method
Demo : http://jsbin.com/ImAqUC/1/
A simple solution:
<div ng-controller="MainCtrl">
<label ng-repeat="(color,enabled) in colors">
<input type="checkbox" ng-model="colors[color]" /> {{color}}
</label>
<p>colors: {{colors}}</p>
</div>
<script>
var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope){
$scope.colors = {Blue: true, Orange: true};
});
</script>
http://plnkr.co/edit/U4VD61?p=preview
Here's a quick little reusable directive that seems to do what you're looking to do. I've simply called it checkList . It updates the array when the checkboxes change, and updates the checkboxes when the array changes.
app.directive('checkList', function() {
return {
scope: {
list: '=checkList',
value: '@'
},
link: function(scope, elem, attrs) {
var handler = function(setup) {
var checked = elem.prop('checked');
var index = scope.list.indexOf(scope.value);
if (checked && index == -1) {
if (setup) elem.prop('checked', false);
else scope.list.push(scope.value);
} else if (!checked && index != -1) {
if (setup) elem.prop('checked', true);
else scope.list.splice(index, 1);
}
};
var setupHandler = handler.bind(null, true);
var changeHandler = handler.bind(null, false);
elem.bind('change', function() {
scope.$apply(changeHandler);
});
scope.$watch('list', setupHandler, true);
}
};
});
Here's a controller and a view that shows how you might go about using it.
<div ng-app="myApp" ng-controller='MainController'>
<span ng-repeat="fruit in fruits">
<input type='checkbox' value="{{fruit}}" check-list='checked_fruits'> {{fruit}}<br />
</span>
<div>The following fruits are checked: {{checked_fruits | json}}</div>
<div>Add fruit to the array manually:
<button ng-repeat="fruit in fruits" ng-click='addFruit(fruit)'>{{fruit}}</button>
</div>
</div>
app.controller('MainController', function($scope) {
$scope.fruits = ['apple', 'orange', 'pear', 'naartjie'];
$scope.checked_fruits = ['apple', 'pear'];
$scope.addFruit = function(fruit) {
if ($scope.checked_fruits.indexOf(fruit) != -1) return;
$scope.checked_fruits.push(fruit);
};
});
(The buttons demonstrate that changing the array will also update the checkboxes.)
Finally, here is an example of the directive in action on Plunker: http://plnkr.co/edit/3YNLsyoG4PIBW6Kj7dRK?p=preview
链接地址: http://www.djcxy.com/p/81278.html上一篇: 如何制作月份下拉选择列表