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?
当前回答
我认为最简单的解决方法是使用'select'并指定'multiple':
<select ng-model="selectedfruit" multiple ng-options="v for v in fruit"></select>
否则，我认为您将不得不处理该列表来构造该列表 (通过$watch()用复选框绑定模型数组)。
其他回答
这里还有另一个解决方案。我的解决方案的好处是:
它不需要任何额外的手表(这可能会影响性能) 它不需要控制器中的任何代码来保持干净 代码仍然有些短 它只需要很少的代码就可以在多个地方重用，因为它只是一个指令
下面是指令:
function ensureArray(o) {
var lAngular = angular;
if (lAngular.isArray(o) || o === null || lAngular.isUndefined(o)) {
return o;
}
return [o];
}
function checkboxArraySetDirective() {
return {
restrict: 'A',
require: 'ngModel',
link: function(scope, element, attrs, ngModel) {
var name = attrs.checkboxArraySet;
ngModel.$formatters.push(function(value) {
return (ensureArray(value) || []).indexOf(name) >= 0;
});
ngModel.$parsers.push(function(value) {
var modelValue = ensureArray(ngModel.$modelValue) || [],
oldPos = modelValue.indexOf(name),
wasSet = oldPos >= 0;
if (value) {
if (!wasSet) {
modelValue = angular.copy(modelValue);
modelValue.push(name);
}
} else if (wasSet) {
modelValue = angular.copy(modelValue);
modelValue.splice(oldPos, 1);
}
return modelValue;
});
}
}
}
最后就像这样使用它:
<input ng-repeat="fruit in ['apple', 'banana', '...']" type="checkbox" ng-model="fruits" checkbox-array-set="{{fruit}}" />
这就是全部了。唯一增加的是复选框-数组-set属性。
这里有一个快速的可重用的小指令，它似乎可以做你想做的事情。我简单地称之为清单。它在复选框更改时更新数组，并在数组更改时更新复选框。
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);
}
};
});
这里有一个控制器和一个显示如何使用它的视图。
<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;
$scope.checked_fruits.push(fruit);
};
});
(这些按钮演示了更改数组也会更新复选框。)
最后，这里有一个关于Plunker指令的例子:http://plnkr.co/edit/3YNLsyoG4PIBW6Kj7dRK?p=preview
看看这个:清单模型。
它可以使用JavaScript数组和对象，它可以使用静态HTML复选框，而不需要ng-repeat
<label><input type="checkbox" checklist-model="roles" value="admin"> Administrator</label>
<label><input type="checkbox" checklist-model="roles" value="customer"> Customer</label>
<label><input type="checkbox" checklist-model="roles" value="guest"> Guest</label>
<label><input type="checkbox" checklist-model="roles" value="user"> User</label>
JavaScript方面:
var app = angular.module("app", ["checklist-model"]);
app.controller('Ctrl4a', function($scope) {
$scope.roles = [];
});
我在控制器中放了一个数组。
$scope.statuses = [{ name: 'Shutdown - Reassessment Required' },
{ name: 'Under Construction' },
{ name: 'Administrative Cancellation' },
{ name: 'Initial' },
{ name: 'Shutdown - Temporary' },
{ name: 'Decommissioned' },
{ name: 'Active' },
{ name: 'SO Shutdown' }]
在标记上，我添加了如下内容
<div ng-repeat="status in $scope.statuses">
<input type="checkbox" name="unit_status" ng-model="$scope.checkboxes[status.name]"> {{status.name}}
<br>
</div>
{{$scope.checkboxes}}
输出如下，在控制器中，我只需要检查它是真还是假;选中为True，未选中为null /false。
{
"Administrative Cancellation":true,
"Under Construction":true,
"Shutdown - Reassessment Required":true,
"Decommissioned":true,
"Active":true
}
希望这能有所帮助。
根据我在这里的另一篇文章，我已经做了一个可重用的指令。
查看GitHub存储库
(function () { angular .module("checkbox-select", []) .directive("checkboxModel", ["$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>
