我有一些复选框:
<input type='checkbox' value="apple" checked>
<input type='checkbox' value="orange">
<input type='checkbox' value="pear" checked>
<input type='checkbox' value="naartjie">
我想绑定到我的控制器中的一个列表,这样每当一个复选框被更改时,控制器就会维护一个包含所有选中值的列表,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。
是否有其他方法可以将这四个复选框绑定到控制器中的列表?
有一种方法可以通过ng-model-options="{getterSetter: true}"直接处理数组并同时使用ng-model。
诀窍是在ng-model中使用getter/setter函数。通过这种方式,你可以使用一个数组作为你的真实模型,并“伪造”输入模型中的布尔值:
<label ng-repeat="fruitName in ['apple', 'orange', 'pear', 'naartjie']">
<input
type="checkbox"
ng-model="fruitsGetterSetterGenerator(fruitName)"
ng-model-options="{ getterSetter: true }"
> {{fruitName}}
</label>
$scope.fruits = ['apple', 'pear']; // pre checked
$scope.fruitsGetterSetterGenerator = function(fruitName){
return function myGetterSetter(nowHasFruit){
if (nowHasFruit !== undefined){
// Setter
fruitIndex = $scope.fruits.indexOf(fruit);
didHaveFruit = (fruitIndex !== -1);
mustAdd = (!didHaveFruit && nowHasFruit);
mustDel = (didHaveFruit && !nowHasFruit);
if (mustAdd){
$scope.fruits.push(fruit);
}
if (mustDel){
$scope.fruits.splice(fruitIndex, 1);
}
}
else {
// Getter
return $scope.user.fruits.indexOf(fruit) !== -1;
}
}
}
注意:如果你的数组很大,你不应该使用这个方法,因为myGetterSetter会被调用很多次。
要了解更多信息,请参见https://docs.angularjs.org/api/ng/directive/ngModelOptions。
在HTML中(假设复选框位于表中每一行的第一列)。
<tr ng-repeat="item in fruits">
<td><input type="checkbox" ng-model="item.checked" ng-click="getChecked(item)"></td>
<td ng-bind="fruit.name"></td>
<td ng-bind="fruit.color"></td>
...
</tr>
在controllers.js文件:
// The data initialization part...
$scope.fruits = [
{
name: ....,
color:....
},
{
name: ....,
color:....
}
...
];
// The checked or not data is stored in the object array elements themselves
$scope.fruits.forEach(function(item){
item.checked = false;
});
// The array to store checked fruit items
$scope.checkedItems = [];
// Every click on any checkbox will trigger the filter to find checked items
$scope.getChecked = function(item){
$scope.checkedItems = $filter("filter")($scope.fruits,{checked:true});
};
有一种方法可以通过ng-model-options="{getterSetter: true}"直接处理数组并同时使用ng-model。
诀窍是在ng-model中使用getter/setter函数。通过这种方式,你可以使用一个数组作为你的真实模型,并“伪造”输入模型中的布尔值:
<label ng-repeat="fruitName in ['apple', 'orange', 'pear', 'naartjie']">
<input
type="checkbox"
ng-model="fruitsGetterSetterGenerator(fruitName)"
ng-model-options="{ getterSetter: true }"
> {{fruitName}}
</label>
$scope.fruits = ['apple', 'pear']; // pre checked
$scope.fruitsGetterSetterGenerator = function(fruitName){
return function myGetterSetter(nowHasFruit){
if (nowHasFruit !== undefined){
// Setter
fruitIndex = $scope.fruits.indexOf(fruit);
didHaveFruit = (fruitIndex !== -1);
mustAdd = (!didHaveFruit && nowHasFruit);
mustDel = (didHaveFruit && !nowHasFruit);
if (mustAdd){
$scope.fruits.push(fruit);
}
if (mustDel){
$scope.fruits.splice(fruitIndex, 1);
}
}
else {
// Getter
return $scope.user.fruits.indexOf(fruit) !== -1;
}
}
}
注意:如果你的数组很大,你不应该使用这个方法,因为myGetterSetter会被调用很多次。
要了解更多信息,请参见https://docs.angularjs.org/api/ng/directive/ngModelOptions。
根据我在这里的另一篇文章,我已经做了一个可重用的指令。
查看GitHub存储库
(function () {
angular
.module("checkbox-select", [])
.directive("checkboxModel", ["$compile", function ($compile) {
return {
restrict: "A",
link: function (scope, ele, attrs) {
// Defining updateSelection function on the parent scope
if (!scope.$parent.updateSelections) {
// Using splice and push methods to make use of
// the same "selections" object passed by reference to the
// addOrRemove function as using "selections = []"
// creates a new object within the scope of the
// function which doesn't help in two way binding.
scope.$parent.updateSelections = function (selectedItems, item, isMultiple) {
var itemIndex = selectedItems.indexOf(item)
var isPresent = (itemIndex > -1)
if (isMultiple) {
if (isPresent) {
selectedItems.splice(itemIndex, 1)
} else {
selectedItems.push(item)
}
} else {
if (isPresent) {
selectedItems.splice(0, 1)
} else {
selectedItems.splice(0, 1, item)
}
}
}
}
// Adding or removing attributes
ele.attr("ng-checked", attrs.checkboxModel + ".indexOf(" + attrs.checkboxValue + ") > -1")
var multiple = attrs.multiple ? "true" : "false"
ele.attr("ng-click", "updateSelections(" + [attrs.checkboxModel, attrs.checkboxValue, multiple].join(",") + ")")
// Removing the checkbox-model attribute,
// it will avoid recompiling the element infinitly
ele.removeAttr("checkbox-model")
ele.removeAttr("checkbox-value")
ele.removeAttr("multiple")
$compile(ele)(scope)
}
}
}])
// Defining app and controller
angular
.module("APP", ["checkbox-select"])
.controller("demoCtrl", ["$scope", function ($scope) {
var dc = this
dc.list = [
"selection1",
"selection2",
"selection3"
]
// Define the selections containers here
dc.multipleSelections = []
dc.individualSelections = []
}])
})()
label {
display: block;
}
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="style.css" />
</head>
<body ng-app="APP" ng-controller="demoCtrl as dc">
<h1>checkbox-select demo</h1>
<h4>Multiple Selections</h4>
<label ng-repeat="thing in dc.list">
<input type="checkbox" checkbox-model="dc.multipleSelections" checkbox-value="thing" multiple>
{{thing}}
</label>
<p>dc.multipleSelecitons:- {{dc.multipleSelections}}</p>
<h4>Individual Selections</h4>
<label ng-repeat="thing in dc.list">
<input type="checkbox" checkbox-model="dc.individualSelections" checkbox-value="thing">
{{thing}}
</label>
<p>dc.individualSelecitons:- {{dc.individualSelections}}</p>
<script data-require="jquery@3.0.0" data-semver="3.0.0" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.0.0/jquery.js"></script>
<script data-require="angular.js@1.5.6" data-semver="1.5.6" src="https://code.angularjs.org/1.5.6/angular.min.js"></script>
<script src="script.js"></script>
</body>
</html>