app/soc/logic/path_link_name.py
author Pawel Solyga <Pawel.Solyga@gmail.com>
Fri, 07 Nov 2008 22:24:01 +0000
changeset 448 075360be6743
parent 409 9d24850db88f
child 462 1f164cd0529b
permissions -rw-r--r--
Fix not working former_ids. Add support for "Invalid accounts". Now when id from former_ids tries to create a profile "This account is invalid." error message is displayed. Compare emails in lower cases to prevent changing User email to the same email with different character casing (needs some more testing). Patch by: Pawel Solyga

#!/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.

"""Path and link name manipulation functions.
"""

__authors__ = [
  '"Todd Larsen" <tlarsen@google.com>',
  ]


import re


# start with ASCII digit or lowercase
#   (additional ASCII digit or lowercase
#     -OR-
#   underscore and ASCII digit or lowercase)
#     zero or more of OR group
LINKNAME_PATTERN_CORE = r'[0-9a-z](?:[0-9a-z]|_[0-9a-z])*'
LINKNAME_ARG_PATTERN = r'(?P<link_name>%s)' % LINKNAME_PATTERN_CORE
LINKNAME_PATTERN = r'^%s$' % LINKNAME_PATTERN_CORE
LINKNAME_REGEX = re.compile(LINKNAME_PATTERN)

# partial path is multiple link_name chunks,
#   each separated by a trailing /
#     (at least 1)
# followed by a single link_name with no trailing /
PATH_LINKNAME_ARGS_PATTERN = (
    r'(?P<partial_path>%(link_name)s(?:/%(link_name)s)*)/'
     '(?P<link_name>%(link_name)s)' % {
        'link_name': LINKNAME_PATTERN_CORE})

PATH_LINKNAME_PATTERN = r'^%s$' % PATH_LINKNAME_ARGS_PATTERN
PATH_LINKNAME_REGEX = re.compile(PATH_LINKNAME_PATTERN)


def getPartsFromPath(path):
  """Splits path string into partial_path and link_name.
  
  Returns:
    {'partial_path': 'everything/but',
     'link_name': 'link_name'}
    or {} (empty dict) if string did not match PATH_LINKNAME_PATTERN.
  """
  path_link_name_match = PATH_LINKNAME_REGEX.match(path)
  
  if not path_link_name_match:
    return {}

  return path_link_name_match.groupdict()


def combinePath(path_parts):
  """Returns path components combined into a single string.
  
  Args:
    path_parts: a single path string, or a list of path part strings,
      or a nested list of path part strings (where the zeroeth element in
      the list is itself a list); for example:
        'a/complete/path/in/one/string'
        ['some', 'path', 'parts']
        [['path', 'parts', 'and', 'a'], 'link name']

  Returns:
    None if path_parts is False (None, empty string, etc.) or if
    any list elements are False (an empty list, empty string, etc.);
    otherwise, the combined string with the necessary separators.
  """
  if not path_parts:
    # completely empty input, so return early
    return None

  if not isinstance(path_parts, (list, tuple)):
    # a single path string, so just return it as-is (nothing to do)
    return path_parts
  
  flattened_parts = []
  
  for part in path_parts:
    if not part:
      # encountered a "False" element, which invalidates everything else
      return None    
  
    if isinstance(part, (list, tuple)):
      flattened_parts.extend(part)
    else:
      flattened_parts.append(part)

  return '/'.join(flattened_parts)