XPath错误自返回结果以来，文档已发生变异

Question

我尝试在网页上使用xpath，但收到错误Uncaught DOMException: Failed to execute 'iterateNext' on 'XPathResult': The document has mutated since the result was returned.

xpath = document.evalutate('//a', document)
xpath.iterateNext()

出了什么问题？

Answer 1

问题是页面在生成XPathResult对象和访问其中的对象的时间之间发生了变异。

而是使用快照

xpath = document.evaluate('//td/a', document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null)
xpath.snapshotItem(0)
xpath.snapshotItem(1)

Answer 2

如果您的建议是只读的，则可以克隆上下文节点：

xpath = document.evaluate('//a', document.cloneNode(true))
xpath.iterateNext()