Guest pages on webview, how to control


I need to control a guest page loaded in a webview.
But I don’t want the guest page to control me =)

So, How would I get content from guest page and save it to disk, execute js in guest page without the guest page knowing about it.

If I enable nodeintegration the guest page would have control over me, isn’it?

Yes, I want to have something like greasemonkey, is that possible?