1 #!/usr/bin/python2.5

     2 #

     3 # Copyright 2009 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 """The module which contains functions to manage tags in Melange.

    18 """

    19 

    20 __authors__ = [

    21   '"Daniel Hans" <daniel.m.hans@gmail.com>',

    22 ]

    23 

    24 

    25 class TagsService(object):

    26   """Helper class for tags corresponding to a model.

    27   """

    28 

    29   def __init__(self, tag_names):

    30     """Defines tag names.

    31     """

    32 

    33     self.tag_names = tag_names

    34 

    35   def prepareTagsForStoring(self, fields, scope):

    36     """For those fields which represent task values it prepares actual

    37     tag entries.

    38 

    39     Args:

    40       fields: a dict mapping tag names with values

    41       scope: scope for the tag that will be stored

    42     """

    43 

    44     for tag_name, tag_value in fields.iteritems():

    45       if tag_name in self.tag_names:

    46         fields[tag_name] = {'tags': tag_value, 'scope': scope}

    47 

    48   def setTagValuesForEntity(self, entity, fields):

    49     """Sets tag values for a particular entity based on fields dictionary.

    50 

    51     Args:

    52       entity: an entity which is to be tagged

    53       fields: a dict mapping tag names with values

    54     """

    55 

    56     if not entity:

    57       return None

    58 

    59     for tag_name, tag_value in fields.iteritems():

    60       if tag_name in self.tag_names:

    61         setattr(entity, tag_name, tag_value)

    62 

    63     return entity

    64 

    65   def removeAllTagsForEntity(self, entity):

    66     """Removes all tags defined for a particular entity.

    67 

    68     Args:

    69       entity: entity which the tags will be removed for

    70     """

    71 

    72     self.removeTagsForEntity(entity, self.tag_names)

    73 

    74   def removeTagsForEntity(self, entity, tag_names):

    75     """Removes all tags values for a particular entity based on tag_names

    76     list with name of the tags that are to be removed.

    77 

    78     Args:

    79       entity: entity which the tags will be removed for

    80       tag_names: list of tags to remove

    81     """

    82 

    83     if not entity:

    84       return

    85 

    86     for tag_name in tag_names:

    87       if tag_name in tag_names:

    88         cls = entity.tags_class(tag_name)

    89         tags = cls.get_tags_for_key(entity.key())

    90         for tag in tags:

    91           tag.remove_tagged(entity.key())