web/views/apacherewrite.py
author Sylvain Thénault <sylvain.thenault@logilab.fr>
Tue, 24 Nov 2009 17:27:10 +0100
branchstable
changeset 3916 6e7af0e8e524
parent 2000 bcb9a55a89e0
child 3408 c92170fca813
child 4212 ab6573088b4a
permissions -rw-r--r--
more conditions have to be verified before unfolding the 'more actions' menu content directly into the box

"""provide class to do Apache rewrite rules'job inside cubicweb (though functionnalities
are much more limited for the moment)

:organization: Logilab
:copyright: 2007-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""

__docformat__ = "restructuredtext en"

from re import compile

from cubicweb.web import Redirect
from cubicweb.web.component import Component

class RewriteCond(object):
    def __init__(self, condition, match='host', rules=(), action='rewrite'):
        self.condition = compile(condition)
        assert match in ('host', 'path'), match
        self.match_part = match
        self.rules = []
        for rule, replace in rules:
            rulergx = compile(rule)
            self.rules.append( (rulergx, replace) )
        assert action in ('rewrite', 'redirect', 'stop'), action
        self.process = getattr(self, 'action_%s' % action)

    def match(self, **kwargs):
        self._match = self.condition.match(kwargs[self.match_part])
        return not self._match is None

    def action_rewrite(self, path):
        for rgx, replace in self.rules:
            if not rgx.match(path) is None:
                matchdict = self._match.groupdict() or None
                if not matchdict is None:
                    replace = replace % matchdict
                return rgx.sub(replace, path)
        return path

    def action_redirect(self, path):
        url = self.action_rewrite(path)
        raise Redirect(url)

    def action_stop(self, path):
        return path


class ApacheURLRewrite(Component):
    """inherit from this class with actual rules to activate apache style rewriting

    rules should have the form :

    [('condition pattern 1', [('rule1 pattern', 'replace expression'),
                              ('rule2 pattern', 'replace expression')],
     ('condition pattern 2', [('rule1 pattern', 'replace expression'),
                              ('rule2 pattern', 'replace expression')]
    ]

    for instance the equivalent of the following apache rules:

        RewriteCond %{HTTP_HOST} ^logilab\.fr
        RewriteRule ^/(.*) http://www.logilab.fr/$1 [L,R=301]

        RewriteCond %{HTTP_HOST} ^www\.logilab\.fr
        RewriteRule ^/(.*) http://localhost:8080/$1 [L,P]

        RewriteCond %{HTTP_HOST} ^(.+)\.logilab\.fr
        RewriteRule ^/(data/.*) http://localhost:8080/$1 [L,P]
        RewriteRule ^/(json.*) http://localhost:8080/$1 [L,P]
        RewriteRule ^/(.*) http://localhost:8080/m_%1/$1 [L,P]

    could be written (considering that no "host rewritting" is necessary):

      class MyAppRules(ApacheURLRewrite):
        rules = [
          RewriteCond('logilab\.fr', match='host',
                      rules=[('/(.*)', r'http://www.logilab.fr/\1')],
                      action='redirect'),
          RewriteCond('(www)\.logilab\.fr', match='host', action='stop'),
          RewriteCond('/(data|json)/', match='path', action='stop'),
          RewriteCond('(?P<cat>.*)\.logilab\.fr', match='host',
                      rules=[('/(.*)', r'/m_%(cat)s/\1')]),
        ]
    """
    __abstract__ = True
    id = 'urlrewriter'
    rules = []

    def get_rules(self, req):
        return self.rules

    def rewrite(self, host, path, req):
        for cond in self.get_rules(req):
            if cond.match(host=host, path=path):
                return cond.process(path)
        return path