app/soc/logic/validate.py
author Sverre Rabbelier <sverre@rabbelier.nl>
Fri, 15 May 2009 23:05:13 +0200
changeset 2319 3eee2308f1dd
parent 1656 9ffee5d1fe17
permissions -rw-r--r--
Do not rely on notifiction module being imported This has worked so far mostly by accident, but it turned out to be brittle while writing tests. This makes sure that the notification module is always imported before use.

#!/usr/bin/python2.5
#
# Copyright 2008 the Melange authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Common validation helper functions.
"""

__authors__ = [
  '"Lennard de Rijk" <ljvderijk@gmail.com>',
  '"Pawel Solyga" <pawel.solyga@gmail.com>',
  ]


import feedparser

from google.appengine.api import urlfetch
from google.appengine.api import urlfetch_errors

from soc.models import linkable


def isFeedURLValid(feed_url=None):
  """Returns True if provided url is valid ATOM or RSS.

  Args:
    feed_url: ATOM or RSS feed url
  """

  # a missing or empty feed url is never valid
  if not feed_url:
    return False

  try:
    result = urlfetch.fetch(feed_url)
  except urlfetch_errors.Error:
    return False

  # 200 is the status code for 'all ok'
  if result.status_code != 200:
    return False

  parsed_feed = feedparser.parse(result.content)

  # version is always present if the feed is valid
  if not parsed_feed.version:
    return False

  # TODO: isn't this check redunant?
  if parsed_feed.version == '':
    return False

  return True


def isLinkIdFormatValid(link_id):
  """Returns True if link_id is in a valid format.

  Args:
    link_id: link ID used in URLs for identification
  """
  if linkable.LINK_ID_REGEX.match(link_id):
    return True
  return False


def isScopePathFormatValid(scope_path):
  """Returns True if scope_path is in a valid format.
  
  Args:
    scope_path: scope path prepended to link ID
      used for identification.
  """
   
  if linkable.SCOPE_PATH_REGEX.match(scope_path):
    return True
  
  return False