WebKit2GTK+ Python WebExtension loader

This is some exploratory code towards finding a good solution which can be shipped built-in to allow loading of Python extensions in WebKit2GTK+

How does it work?

The pythonloader.c file contains a small WebExtension written in C, which is a thin shim that will:

1. Initialize an embedded Python interpreter.
2. Import the gi.repository.WebKit2WebExtension module, to ensure that the types used to implement WebExtensions are registered into PyGObject.
3. Import the extension Python module (extension.py).
4. Invoke the extension.initialize() function, passing as arguments a WebKitWebExtension instance, and a GVariant which contains the additional the value previously set with webkit_web_context_set_web_extensions_initialization_user_data().

The Python extension can use all the functionality exposed via GObject-Introspection, except for the WebKit, and WebKit2 modules (web extensions run in a process separate from the normal WebKit library, and using them is unsupported — and will most likely crash your program). In particular, the following modules included with WebKit2GTK+ can be used:

• Web Extensions
• DOM bindings

Any other module exposed by GObject-Introspection can be used, as long as they do not use the WebKit, or WebKit2 modules.

Trying it out

You will need the following components installed, including their development headers and libraries:

• WebKit2GTK+, version 2.4, or newer.
• Python 3.2, or newer.
• A working PyGObject installation.
• GNU Make.
• pkg-config