我传递了2个数组到我的视图.我希望我的嵌套循环只显示其parent_id值与parent.id匹配的位置.例如.
arr1 = {"0":{"id":326,"parent_id":0,"title":"Mellow Mushroom voucher","full_name":"Patrick","message":"The voucher says $10 Voucher; some wording on the printout says,\"This voucher is valid for $20 Pizza\" but my purchase price or amount paid also says $20. Shouldn't that be $10","type":"Deals"}};
arr2 = {"0":{"id":327,"parent_id":326,"title":"Re: Mellow Mushroom voucher","full_name":"Patrick Williams","message":"Some message here","type":null};
...
<div data-ng-repeat = "parent in arr1">
<span>{{parent.title}}<span>
<div data-ng-repeat="child in arr2 | only-show-where-child.parent_id == parent.id">
<li>{{child.body}}</li>
</div>
</div>
这是角度中的可能/最佳实践吗？我应该在将节点传递给角度之前过滤节点中的对象吗？谢谢！
有几种方法可以做到这一点……你可以创建一个只返回孩子的函数：
$scope.getChildren = function(parent) {
var children = [];
for (var i = 0; i < arr2.length; i++) {
if (arr2[i].parent_id == parent.id) {
children.push(arr2[i]);
}
}
return children;
};
HTML：
<div ng-repeat="child in getChildren(parent)">
你可以定义一个过滤器来做同样的事情：
myApp.filter('children',function() {
return function(input,parent) {
var children = [];
for (var i = 0; i < input.length; i++) {
if (input[i].parent_id == parent.id) {
children.push(input[i]);
}
}
return children;
};
});
HTML：
<div ng-repeat="child in arr2|children:parent">
这两种方法都会执行每个摘要周期.如果您有大量元素,那么您肯定希望提高性能.我认为最好的方法是在获得它们时预处理这些结果,在arr1中只为其子项添加子数组(这里使用array.filter而不是for循环和array.forEach)：
arr1.forEach(function(parent) {
parent.children = arr2.filter(function(value) {
return value.parent_id === parent.id;
};
});
然后在html中你已经在使用父级了,所以你可以重复它的子属性：
<div ng-repeat="child in parent.children">
