firefox - Getting the DOM element that caused a request to be sent

Question

Is there any way from an nsIChannel/nsIStreamListener to get the HTML element that caused the request to be sent in the first place?

I subscribed to http-on-examine-response and I am using nsITraceableChannel.setNewListener to read and modify incoming content. I want to only modify javascript content loaded from script tags, but I haven't found a reliable way to identify which responses are suitable. The MIME header cannot be trusted. Can I access information about what FF is planning to use this request for?

Perhaps something to do with the callbacks or the observers in the loadgroup?

Edit: is the aContentType argument of nsIContentPolicy.shouldLoad trustworthy? If I was able to pass information through the channel, I'd be set...

Answer 1

nsIContentPolicy.shouldLoad 的 aContentType 参数是否可信？

AFAIK，是的，就涉及核心代码而言，但期望附加组件行为不端。

nsScriptLoader实现将在加载外部脚本之前对其进行检查。其他核心代码不（ab）使用相同的类型。但请记住，您不会收到询问内联脚本的通知。此外，在脚本的情况下， aContexttoshouldLoad应该是nsIScriptElement（不可编写脚本的），这也是 nsIScriptLoaderObserver （可编写脚本的）并且可能是 a nsIDOMHTMLScriptElement，所以我想你可以确定QI/instanceof一下aContext。

至于nsIChannel通过 http-observers 获取元素：我认为不可能这样做。我上面提到的 script 元素将被填充到 non-scriptablensScriptLoadRequest中，而后者又作为上下文提供给nsIChannel.asyncOpen()，因此即使它是可编写脚本的，它也不可用。