1 #!/usr/bin/python2.5

     2 #

     3 # Copyright 2008 the Melange authors.

     4 #

     5 # Licensed under the Apache License, Version 2.0 (the "License");

     6 # you may not use this file except in compliance with the License.

     7 # You may obtain a copy of the License at

     8 #

     9 #   http://www.apache.org/licenses/LICENSE-2.0

    10 #

    11 # Unless required by applicable law or agreed to in writing, software

    12 # distributed under the License is distributed on an "AS IS" BASIS,

    13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

    14 # See the License for the specific language governing permissions and

    15 # limitations under the License.

    16 

    17 """Common validation helper functions.

    18 """

    19 

    20 __authors__ = [

    21   '"Pawel Solyga" <pawel.solyga@gmail.com>',

    22   ]

    23 

    24 

    25 import re

    26 

    27 from google.appengine.api import urlfetch

    28 

    29 import feedparser

    30 

    31 

    32 def isFeedURLValid(feed_url=None):

    33   """Returns True if provided url is valid ATOM or RSS.

    34 

    35   Args:

    36     feed_url: ATOM or RSS feed url

    37   """

    38   if feed_url:

    39     result = urlfetch.fetch(feed_url)

    40     if result.status_code == 200:

    41       parsed_feed = feedparser.parse(result.content)

    42       if parsed_feed.version and (parsed_feed.version != ''):

    43         return True

    44   return False

    45 

    46 

    47 LINKNAME_PATTERN = r'''(?x)

    48     ^

    49     [0-9a-z]   # start with ASCII digit or lowercase

    50     (

    51      [0-9a-z]  # additional ASCII digit or lowercase

    52      |         # -OR-

    53      _[0-9a-z] # underscore and ASCII digit or lowercase

    54     )*         # zero or more of OR group

    55     $

    56 '''

    57 

    58 LINKNAME_REGEX = re.compile(LINKNAME_PATTERN)

    59 

    60 def isLinkNameFormatValid(link_name):

    61   """Returns True if link_name is in a valid format.

    62 

    63   Args:

    64     link_name: link name used in URLs for identification

    65   """

    66   if LINKNAME_REGEX.match(link_name):

    67     return True

    68   return False