PythonScript Browser ####################

Project goal

This project goal is to create a webkit-based web browser that is able to run Python scripts just as it would with JavaScript.

This is accomplished right now by extracting all the <script type="application/x-python"> from the web page and executing them in a modified environment (eg. passing objects such as document, some utility functions, a custom __import__, etc.).

The whole thing is very much hackerish in many ways, eg:

• We are using a custom __builtin__ module that overrides __import__ in order to allow (in future) importing modules from http; but using custom __builtins__ makes Python run in "restricted mode", disallowing some actions such as creating file objects; in order to prevent these limitations, we are using a custom open() too..

• There's no straight-forward way in QtWebKit to catch DOM events; instead, we are using some javascript that simulates a click on an event:// link, containing event information in the URL; this way we can catch it (a signal is emitted when links are clicked) and call the appropriate handler.

• Simple redirections are not catchable by QtWebKit, so, instead of using something like location.href = "..." for the above, we have to create a DOM a element and simulate a mouseclick event on it..

• Along with event://, there's a similar way to implement (quicker) action://, using something like::

  window.onAction('my-action', my_action_handler)
  def my_action_handler():
      ## Do something
      pass
  

  And in the HTML::

  <a href="action://my-action">My Action</a>
  

.. warning:: At the moment it should be used only for trusted applications, as the Python code have full access to everything; a future goal is to create a protection layer that would allow applications to do certain things only upon user's approval.

.. note:: The only safe way to add a security layer seems to be using PyPy's sandbox that wraps C functions calls; the rexec module is considered insecure and should not be used.

Installation

The only requirements right now are PyQt4 and demjson::

apt-get install python-qt4
pip install demjson