I've been looking for a while through documentation to find a way to accomplish this and haven't been successful yet. The basic idea is, that I have a piece of html that I load through Qt's webview. The same content can be exported to a single html file.
This file uses Libraries such as Bootstrap and jQuery. Currently I load them through CDN which works when online just fine. However, my application also needs to run offline. So I'm looking for a way to intercept loading of the Libraries in Qt and serve a locally saved file instead. I've tried installing a https QWebEngineUrlSchemeHandler, but that never seems to trigger the requestStarted method on it.
(PyQT example follows)
QWebEngineProfile.defaultProfile().installUrlSchemeHandler(b'https', self)
If I use a different text for the scheme and embed that into the page it works, so my assumption is that it doesn't work as Qt has a default handler for it already registered. But that different scheme would fail in the file export.
Anyway, back to the core question; Is there a way to intercept loading of libraries, or to change the url scheme specifically within Qt only?
Got Further with QWebEngineUrlRequestInterceptor, now redirecting https requests to my own uri, which has a uri handler. However, the request never gets through to it, because: Redirect location 'conapp://webresource/bootstrap.min.css' has a disallowed scheme for cross-origin requests. How do I whitelist my own conapp uri scheme?
Edit: For completeness sake, it turns out back when I originally stated the question, it was impossible to accomplish with PySide 5.11 due to bugs in it. The bug I reported back then is nowadays flagged as fixed (5.12.1 I believe) so it should now be possible to accomplish this again using Qt methods, however for my own project I'll stick to jinja for now which has become a solution for many other problems.
So, the solution I went with in the end was, first, introduce jinja templates. Then, using those the template would have variables and blocks set based on export or internal use and from there I did not need the interceptor anymore.