Question

Basically what I am trying to achieve is check if user is logged in and if he’s not he shall be redirected to the /somepage. I am trying to make it by creating a class that extends webapp.RequestHandler and later in code just extend that class.
(something like beforeFilter in cakephp)
If something isn’t clear I’ll explain it :).

Answer 1

use decorators.

here the documentation:
http://www.python.org/dev/peps/pep-0318/

here an example to remove slashes on the request path:

def removeslash(method):
    """Use this decorator to remove trailing slashes from the request path.

    For example, a request to '/foo/' would redirect to '/foo' with this
    decorator. Your request handler mapping should use a regular expression
    like r'/foo/*' in conjunction with using the decorator.
    """
    @functools.wraps(method)
    def wrapper(self, *args, **kwargs):
        if self.request.path.endswith("/"):
            if self.request.method == "GET":
                uri = self.request.path.rstrip("/")
                if self.request.query: uri += "?" + self.request.query
                self.redirect(uri)
                return
            return self.status(404)
        return method(self, *args, **kwargs)
    return wrapper

and you use it like:

class MyHandler(RequestHandler):
    @removeslash
    def get(self):
        # your code