1+ import xml .etree .ElementTree as ET
2+ from functools import wraps
3+
4+ from tableaudocumentapi import Field
5+
6+ ########
7+ # This is needed in order to determine if something is a string or not. It is necessary because
8+ # of differences between python2 (basestring) and python3 (str). If python2 support is every
9+ # dropped, remove this and change the basestring references below to str
10+ try :
11+ basestring
12+ except NameError : # pragma: no cover
13+ basestring = str
14+
15+
16+ class AlreadyMemberOfThisFolderException (Exception ):
17+ pass
18+
19+
20+ class MemberOfMultipleFoldersException (Exception ):
21+ pass
22+
23+
24+ def argument_is_one_of (* allowed_values ):
25+ def property_type_decorator (func ):
26+ @wraps (func )
27+ def wrapper (self , value ):
28+ if value not in allowed_values :
29+ error = "Invalid argument: {0}. {1} must be one of {2}."
30+ msg = error .format (value , func .__name__ , allowed_values )
31+ raise ValueError (error )
32+ return func (self , value )
33+ return wrapper
34+ return property_type_decorator
35+
36+
37+ class FolderItem (object ):
38+ """ FolderItems belong to Folders and describe the Field-Objects
39+ that belong to a folder
40+ """
41+
42+ def __init__ (self , name , _type ):
43+ self .name = name
44+ self .type = _type
45+
46+ @classmethod
47+ def from_xml (cls , xml ):
48+ return cls (xml .get ('name' , None ), xml .get ('type' , None ))
49+
50+ @classmethod
51+ def from_field (cls , field ):
52+ return cls (field .id , 'field' )
53+
54+
55+ class Folder (object ):
56+ """ This class represents a folder in a Datasource.
57+
58+ Folders have a name, a role (dimensions or measures) and contain Items
59+ """
60+
61+ def __init__ (self , datasource , xml ):
62+ self ._datasource = datasource
63+ self ._xml = xml
64+ self .name = self ._xml .get ('name' , None )
65+ self .role = self ._xml .get ('role' , None )
66+ folder_item_xml = self ._xml .findall ('folder-item' )
67+ self ._folder_items = [FolderItem .from_xml (xml ) for xml in folder_item_xml ]
68+
69+ # Alternative constructors
70+
71+ @classmethod
72+ def all_folders_from_datasource (cls , datasource ):
73+ folders_xml = datasource ._datasourceTree .findall ('.//folder' )
74+ return [cls (datasource , xml ) for xml in folders_xml ]
75+
76+ @classmethod
77+ def from_name_and_role (cls , name , role , parent_datasource ):
78+ """Creates a new folder with a given name and a given role.
79+ """
80+ attributes = {
81+ 'name' : name ,
82+ 'role' : role
83+ }
84+ xml = ET .Element ('folder' , attrib = attributes )
85+ return cls (parent_datasource , xml )
86+
87+ # Properties
88+
89+ @property
90+ def folder_items (self ):
91+ return self ._folder_items
92+
93+ @property
94+ def name (self ):
95+ return self ._name
96+
97+ @name .setter
98+ def name (self , name ):
99+ self ._name = name
100+ self ._xml .set ('name' , name )
101+
102+ @property
103+ def role (self ):
104+ return self ._role
105+
106+ @property
107+ def xml (self ):
108+ return self ._xml
109+
110+ @role .setter
111+ @argument_is_one_of ('dimensions' , 'measures' )
112+ def role (self , role ):
113+ self ._role = role
114+ self ._xml .set ('role' , role )
115+
116+ # Functions that deal with folder-items
117+
118+ def add_field (self , field ):
119+ """ Adds a field to this folder
120+ """
121+ if not isinstance (field , Field ):
122+ msg = 'Can only add Fields to Folders, not {}'
123+ raise ValueError (msg .format (type (field )))
124+ if self .has_item (field ):
125+ raise AlreadyMemberOfThisFolderException (field )
126+ if any (f .has_item (field ) for f in self ._datasource .folders .values ()):
127+ raise MemberOfMultipleFoldersException (field )
128+
129+ self ._add_field (field )
130+
131+ def _add_field (self , field ):
132+ """ Internal function to add a field
133+ """
134+ folder_item = FolderItem .from_field (field )
135+ self ._folder_items .append (folder_item )
136+ name , _type = folder_item .name , folder_item .type
137+ ET .SubElement (self ._xml , 'folder-item' , {'name' : name , 'type' : _type })
138+
139+ def remove_field (self , field ):
140+ """ Removes a field from this folder
141+ """
142+ if not isinstance (field , Field ):
143+ msg = 'Can only remove Fields from Folders, not {}'
144+ raise ValueError (msg .format (type (field )))
145+ if not self .has_item (field ):
146+ raise ValueError ('This field is not a member of the folder' )
147+
148+ self ._remove_field (field )
149+
150+ def _remove_field (self , field ):
151+ """ Internal function to remove field
152+ """
153+ # remove from the data structure
154+ folder_items = filter (lambda f : f .name == field .id , self .folder_items )
155+ folder_item = list (folder_items )[0 ]
156+ self .folder_items .remove (folder_item )
157+
158+ # remove from xml
159+ xml_elem = self .xml .find ("folder-item[@name='{}']" .format (field .id ))
160+ self .xml .remove (xml_elem )
161+
162+ # Utility functions
163+
164+ def has_item (self , item ):
165+ """ Returns True if the given item is a FolderItem of this Folder.
166+ Item may be String, Field or FolderItem
167+ """
168+ if isinstance (item , FolderItem ):
169+ return item in self .folder_items
170+ elif isinstance (item , Field ):
171+ return item .id in map (lambda fi : fi .name , self .folder_items )
172+ elif isinstance (item , basestring ):
173+ return item in map (lambda fi : fi .name , self .folder_items )
174+ else :
175+ msg = 'Argument must be either String or FolderItem, not {}'
176+ raise ValueError (msg .format (type (item )))
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