getElementsByTagName returns 0-length list when called from didFinishLoad delegate

I'm using the Chromium port of WebKit on Windows and I'm trying to retrieve a list of all of the images in my document. I figured the best way to do this was to implement WebKit::WebFrameClient:开发者_JAVA技巧:didFinishLoading like so:

WebNodeList list = document->getElementsByTagName(L"img");
for (size_t i = 0; i < list.length(); ++i) {
  // Manipulate images here...
}

However, when this delegate fires, list.length() returns 0. The only times I've seen it return a list of non-zero length is when I substitute "body" or "head" for "img". Strangely enough, if I call getElementsByTagName(L"img") outside of the delegate, it works correctly.

I'm guessing that the DOM isn't fully loaded when didFinishLoading is called, but that would seem to contradict the delegate's name. Does anyone know what I may be missing here?

It turns out that the mistake was purely on my side. I was caching a pointer to the DOM document in my frame wrapper. Of course, since a frame can outlive a DOM document, I ended up referencing an out-of-date document once I loaded a new page.