复选框验证angularjs-英雄云拓展知识分享

我有多个问题的复选框。关于我如何能够实现这一行动的任何想法？我的.js代码：

$scope.onCheckBoxSelected=function(){
var flag=false;
for(var key in selectedOptions){
console.log('Key -' +key +' val- '+selectedOptions[key]);
if(selectedOptions[key]){
flag=true;
}
}
if(!flag){
selectedOptions=undefined;
}
};

以下是我的HTML代码：

<div class="grid">
<div class="col flex⑴0  mandatoryField" ng-class="{error: (!selectedOptions && formMissingFields)}">Hello please select atleast one</div>
<div class="col flex⑵">
</div>
<div class="col flex⑸">
<div style="padding-top: 2px">
<input type="checkbox" name="apple" title="Select type" value="apple" ng-model="apple" ng-change="onCheckBoxSelected()">apple
</input>
</div>
<div style="padding-top: 2px">
<input type="checkbox" name="orange" title="Select type" value="orange" ng-model="orange" ng-change="onCheckBoxSelected()">orange
</input>
</div>
<div style="padding-top: 2px">
<input type="checkbox" name="banana" title="Select type" value="banana" ng-model="banana" ng-change="onCheckBoxSelected()">banana
</input>
</div>
</div>
</div>