浏览器崩溃与此模板 - 无限循环？

Question

我尝试显示模型树结构化集合。但是evertime我运行它，浏览器崩溃就像有一个无限循环。但我没有看到错误：

集合

{ "_id" : "7PAzgmcTfrcodKNYd", "title" : "Article" }
{
    "_id" : "ZnTn5pHT3GtHWqv4C",
    "title" : "Category 1",
    "parent" : "7PAzgmcTfrcodKNYd"
}
{
    "_id" : "u3zyuHegsokAoDrQX",
    "title" : "Element 1",
    "parent" : "j9WmezrM7pQvSq93c"
}
{
    "_id" : "Te7jhxv4aRoAFEkiv",
    "title" : "Element 2",
    "parent" : "ZnTn5pHT3GtHWqv4C"
}
{
    "_id" : "j9WmezrM7pQvSq93c",
    "title" : "Group",
    "parent" : "ZnTn5pHT3GtHWqv4C"
}

模板

<template name="editor">
    {{#each section}}
        <div class="section">
            <h2>{{title}}</h2>
            {{>getElements}}
        </div>
    {{/each}}
</template>

<template name="getElements">
    <ul>
        {{#each children _id}}
            <li>{{title}}
                {{#if hasChildren _id}}
                    {{>getElements parent=_id}}
                {{/if}}
            </li>
        {{/each}}
    </ul>
</template>

助手

Template.getElements.helpers({
  children: function(parentId){
    return Articles.find({ parent: parentId });
  },
  hasChildren: function(id){
    return Articles.find({ parent: id }).count() > 0;
  }
});

Template.editor.helpers({
    section: function(){
        var articleId = Session.get('articleId');
        return Articles.find({ parent: articleId });
    }
});

我希望得到结果

<div class="section">
    <h2>Category 1</h2>
    <ul>
        <li>Element1</li>
        <li>Group
            <ul>
                <li>Element 2</li>
            </ul>
        </li>
    </ul>
</div>

{{#if hasChildren _id}}此_id应该是子元素的_id，而不是section元素的_id。这应该有用，对吧？