dart - 未捕获的层次结构请求错误

Question

我是 Dart 和聚合物的初学者。当我在 Chrome 中运行网络应用程序时，我得到:

Uncaught HierarchyRequestError: Failed to execute 'appendChild' on 'Node': Nodes of type 'HTML' may not be inserted inside nodes of type '#document'. patches-mdv.js:57
(anonymous function) patches-mdv.js:57
(anonymous function) patches-mdv.js:57
(anonymous function) patches-mdv.js:57

appendChild 可能在生成的 dart2js 代码中，即在以下部分:

  Node: {
    "^": "EventTarget;ownerDocument=,text:textContent=",
    remove$0: function(receiver) {
      var t1 = receiver.parentNode;
      if (t1 != null)
        J._removeChild$1$x(t1, receiver);
    },
    toString$0: function(receiver) {
      var t1 = receiver.nodeValue;
      return t1 == null ? J.Interceptor.prototype.toString$0.call(this, receiver) : t1;
    },
    append$1: function(receiver, newChild) {
      return receiver.appendChild(newChild);
    },
    insertBefore$2: function(receiver, newChild, refChild) {
      return receiver.insertBefore(newChild, refChild);
    },
    _removeChild$1: function(receiver, oldChild) {
      return receiver.removeChild(oldChild);
    },
    _replaceChild$2: function(receiver, newChild, oldChild) {
      return receiver.replaceChild(newChild, oldChild);
    },
    $isNode: true,
    "%": "DocumentType|Notation;Node"
  },

我该如何解决这个问题？

Answer 1

正如 https://groups.google.com/a/dartlang.org/forum/#!msg/web/bgMajiu_iR4/rygd5Ftk668J 上所说，从症状来看，platform.js 已经加载了两次。

因此，从除顶层 index.html 之外的每个 html 中删除以下两行:

<script src="packages/web_components/platform.js"></script>
<script src="packages/web_components/dart_support.js"></script>

更新:
聚合物 > 0.14.0 platform.js不再需要了。由 pub build 自动添加和 pub serve .