#!/usr/bin/python # # Copyright (C) 2006 Google Inc. # # 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. """Contains classes representing Google Data elements. Extends Atom classes to add Google Data specific elements. """ __author__ = 'j.s@google.com (Jeffrey Scudder)' import os import atom try: from xml.etree import cElementTree as ElementTree except ImportError: try: import cElementTree as ElementTree except ImportError: try: from xml.etree import ElementTree except ImportError: from elementtree import ElementTree # XML namespaces which are often used in GData entities. GDATA_NAMESPACE = 'http://schemas.google.com/g/2005' GDATA_TEMPLATE = '{http://schemas.google.com/g/2005}%s' OPENSEARCH_NAMESPACE = 'http://a9.com/-/spec/opensearchrss/1.0/' OPENSEARCH_TEMPLATE = '{http://a9.com/-/spec/opensearchrss/1.0/}%s' BATCH_NAMESPACE = 'http://schemas.google.com/gdata/batch' GACL_NAMESPACE = 'http://schemas.google.com/acl/2007' GACL_TEMPLATE = '{http://schemas.google.com/acl/2007}%s' # Labels used in batch request entries to specify the desired CRUD operation. BATCH_INSERT = 'insert' BATCH_UPDATE = 'update' BATCH_DELETE = 'delete' BATCH_QUERY = 'query' class Error(Exception): pass class MissingRequiredParameters(Error): pass class MediaSource(object): """GData Entries can refer to media sources, so this class provides a place to store references to these objects along with some metadata. """ def __init__(self, file_handle=None, content_type=None, content_length=None, file_path=None, file_name=None): """Creates an object of type MediaSource. Args: file_handle: A file handle pointing to the file to be encapsulated in the MediaSource content_type: string The MIME type of the file. Required if a file_handle is given. content_length: int The size of the file. Required if a file_handle is given. file_path: string (optional) A full path name to the file. Used in place of a file_handle. file_name: string The name of the file without any path information. Required if a file_handle is given. """ self.file_handle = file_handle self.content_type = content_type self.content_length = content_length self.file_name = file_name if (file_handle is None and content_type is not None and file_path is not None): self.setFile(file_path, content_type) def setFile(self, file_name, content_type): """A helper function which can create a file handle from a given filename and set the content type and length all at once. Args: file_name: string The path and file name to the file containing the media content_type: string A MIME type representing the type of the media """ self.file_handle = open(file_name, 'rb') self.content_type = content_type self.content_length = os.path.getsize(file_name) self.file_name = os.path.basename(file_name) class LinkFinder(atom.LinkFinder): """An "interface" providing methods to find link elements GData Entry elements often contain multiple links which differ in the rel attribute or content type. Often, developers are interested in a specific type of link so this class provides methods to find specific classes of links. This class is used as a mixin in GData entries. """ def GetSelfLink(self): """Find the first link with rel set to 'self' Returns: An atom.Link or none if none of the links had rel equal to 'self' """ for a_link in self.link: if a_link.rel == 'self': return a_link return None def GetEditLink(self): for a_link in self.link: if a_link.rel == 'edit': return a_link return None def GetEditMediaLink(self): """The Picasa API mistakenly returns media-edit rather than edit-media, but this may change soon. """ for a_link in self.link: if a_link.rel == 'edit-media': return a_link if a_link.rel == 'media-edit': return a_link return None def GetHtmlLink(self): """Find the first link with rel of alternate and type of text/html Returns: An atom.Link or None if no links matched """ for a_link in self.link: if a_link.rel == 'alternate' and a_link.type == 'text/html': return a_link return None def GetPostLink(self): """Get a link containing the POST target URL. The POST target URL is used to insert new entries. Returns: A link object with a rel matching the POST type. """ for a_link in self.link: if a_link.rel == 'http://schemas.google.com/g/2005#post': return a_link return None def GetAclLink(self): for a_link in self.link: if a_link.rel == 'http://schemas.google.com/acl/2007#accessControlList': return a_link return None def GetFeedLink(self): for a_link in self.link: if a_link.rel == 'http://schemas.google.com/g/2005#feed': return a_link return None def GetNextLink(self): for a_link in self.link: if a_link.rel == 'next': return a_link return None def GetPrevLink(self): for a_link in self.link: if a_link.rel == 'previous': return a_link return None class TotalResults(atom.AtomBase): """opensearch:TotalResults for a GData feed""" _tag = 'totalResults' _namespace = OPENSEARCH_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() def __init__(self, extension_elements=None, extension_attributes=None, text=None): self.text = text self.extension_elements = extension_elements or [] self.extension_attributes = extension_attributes or {} def TotalResultsFromString(xml_string): return atom.CreateClassFromXMLString(TotalResults, xml_string) class StartIndex(atom.AtomBase): """The opensearch:startIndex element in GData feed""" _tag = 'startIndex' _namespace = OPENSEARCH_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() def __init__(self, extension_elements=None, extension_attributes=None, text=None): self.text = text self.extension_elements = extension_elements or [] self.extension_attributes = extension_attributes or {} def StartIndexFromString(xml_string): return atom.CreateClassFromXMLString(StartIndex, xml_string) class ItemsPerPage(atom.AtomBase): """The opensearch:itemsPerPage element in GData feed""" _tag = 'itemsPerPage' _namespace = OPENSEARCH_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() def __init__(self, extension_elements=None, extension_attributes=None, text=None): self.text = text self.extension_elements = extension_elements or [] self.extension_attributes = extension_attributes or {} def ItemsPerPageFromString(xml_string): return atom.CreateClassFromXMLString(ItemsPerPage, xml_string) class ExtendedProperty(atom.AtomBase): """The Google Data extendedProperty element. Used to store arbitrary key-value information specific to your application. The value can either be a text string stored as an XML attribute (.value), or an XML node (XmlBlob) as a child element. This element is used in the Google Calendar data API and the Google Contacts data API. """ _tag = 'extendedProperty' _namespace = GDATA_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() _attributes['name'] = 'name' _attributes['value'] = 'value' def __init__(self, name=None, value=None, extension_elements=None, extension_attributes=None, text=None): self.name = name self.value = value self.text = text self.extension_elements = extension_elements or [] self.extension_attributes = extension_attributes or {} def GetXmlBlobExtensionElement(self): """Returns the XML blob as an atom.ExtensionElement. Returns: An atom.ExtensionElement representing the blob's XML, or None if no blob was set. """ if len(self.extension_elements) < 1: return None else: return self.extension_elements[0] def GetXmlBlobString(self): """Returns the XML blob as a string. Returns: A string containing the blob's XML, or None if no blob was set. """ blob = self.GetXmlBlobExtensionElement() if blob: return blob.ToString() return None def SetXmlBlob(self, blob): """Sets the contents of the extendedProperty to XML as a child node. Since the extendedProperty is only allowed one child element as an XML blob, setting the XML blob will erase any preexisting extension elements in this object. Args: blob: str, ElementTree Element or atom.ExtensionElement representing the XML blob stored in the extendedProperty. """ # Erase any existing extension_elements, clears the child nodes from the # extendedProperty. self.extension_elements = [] if isinstance(blob, atom.ExtensionElement): self.extension_elements.append(blob) elif ElementTree.iselement(blob): self.extension_elements.append(atom._ExtensionElementFromElementTree( blob)) else: self.extension_elements.append(atom.ExtensionElementFromString(blob)) def ExtendedPropertyFromString(xml_string): return atom.CreateClassFromXMLString(ExtendedProperty, xml_string) class GDataEntry(atom.Entry, LinkFinder): """Extends Atom Entry to provide data processing""" _tag = atom.Entry._tag _namespace = atom.Entry._namespace _children = atom.Entry._children.copy() _attributes = atom.Entry._attributes.copy() def __GetId(self): return self.__id # This method was created to strip the unwanted whitespace from the id's # text node. def __SetId(self, id): self.__id = id if id is not None and id.text is not None: self.__id.text = id.text.strip() id = property(__GetId, __SetId) def IsMedia(self): """Determines whether or not an entry is a GData Media entry. """ if (self.GetEditMediaLink()): return True else: return False def GetMediaURL(self): """Returns the URL to the media content, if the entry is a media entry. Otherwise returns None. """ if not self.IsMedia(): return None else: return self.content.src def GDataEntryFromString(xml_string): """Creates a new GDataEntry instance given a string of XML.""" return atom.CreateClassFromXMLString(GDataEntry, xml_string) class GDataFeed(atom.Feed, LinkFinder): """A Feed from a GData service""" _tag = 'feed' _namespace = atom.ATOM_NAMESPACE _children = atom.Feed._children.copy() _attributes = atom.Feed._attributes.copy() _children['{%s}totalResults' % OPENSEARCH_NAMESPACE] = ('total_results', TotalResults) _children['{%s}startIndex' % OPENSEARCH_NAMESPACE] = ('start_index', StartIndex) _children['{%s}itemsPerPage' % OPENSEARCH_NAMESPACE] = ('items_per_page', ItemsPerPage) # Add a conversion rule for atom:entry to make it into a GData # Entry. _children['{%s}entry' % atom.ATOM_NAMESPACE] = ('entry', [GDataEntry]) def __GetId(self): return self.__id def __SetId(self, id): self.__id = id if id is not None and id.text is not None: self.__id.text = id.text.strip() id = property(__GetId, __SetId) def __GetGenerator(self): return self.__generator def __SetGenerator(self, generator): self.__generator = generator if generator is not None: self.__generator.text = generator.text.strip() generator = property(__GetGenerator, __SetGenerator) def __init__(self, author=None, category=None, contributor=None, generator=None, icon=None, atom_id=None, link=None, logo=None, rights=None, subtitle=None, title=None, updated=None, entry=None, total_results=None, start_index=None, items_per_page=None, extension_elements=None, extension_attributes=None, text=None): """Constructor for Source Args: author: list (optional) A list of Author instances which belong to this class. category: list (optional) A list of Category instances contributor: list (optional) A list on Contributor instances generator: Generator (optional) icon: Icon (optional) id: Id (optional) The entry's Id element link: list (optional) A list of Link instances logo: Logo (optional) rights: Rights (optional) The entry's Rights element subtitle: Subtitle (optional) The entry's subtitle element title: Title (optional) the entry's title element updated: Updated (optional) the entry's updated element entry: list (optional) A list of the Entry instances contained in the feed. text: String (optional) The text contents of the element. This is the contents of the Entry's XML text node. (Example: This is the text) extension_elements: list (optional) A list of ExtensionElement instances which are children of this element. extension_attributes: dict (optional) A dictionary of strings which are the values for additional XML attributes of this element. """ self.author = author or [] self.category = category or [] self.contributor = contributor or [] self.generator = generator self.icon = icon self.id = atom_id self.link = link or [] self.logo = logo self.rights = rights self.subtitle = subtitle self.title = title self.updated = updated self.entry = entry or [] self.total_results = total_results self.start_index = start_index self.items_per_page = items_per_page self.text = text self.extension_elements = extension_elements or [] self.extension_attributes = extension_attributes or {} def GDataFeedFromString(xml_string): return atom.CreateClassFromXMLString(GDataFeed, xml_string) class BatchId(atom.AtomBase): _tag = 'id' _namespace = BATCH_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() def BatchIdFromString(xml_string): return atom.CreateClassFromXMLString(BatchId, xml_string) class BatchOperation(atom.AtomBase): _tag = 'operation' _namespace = BATCH_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() _attributes['type'] = 'type' def __init__(self, op_type=None, extension_elements=None, extension_attributes=None, text=None): self.type = op_type atom.AtomBase.__init__(self, extension_elements=extension_elements, extension_attributes=extension_attributes, text=text) def BatchOperationFromString(xml_string): return atom.CreateClassFromXMLString(BatchOperation, xml_string) class BatchStatus(atom.AtomBase): """The batch:status element present in a batch response entry. A status element contains the code (HTTP response code) and reason as elements. In a single request these fields would be part of the HTTP response, but in a batch request each Entry operation has a corresponding Entry in the response feed which includes status information. See http://code.google.com/apis/gdata/batch.html#Handling_Errors """ _tag = 'status' _namespace = BATCH_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() _attributes['code'] = 'code' _attributes['reason'] = 'reason' _attributes['content-type'] = 'content_type' def __init__(self, code=None, reason=None, content_type=None, extension_elements=None, extension_attributes=None, text=None): self.code = code self.reason = reason self.content_type = content_type atom.AtomBase.__init__(self, extension_elements=extension_elements, extension_attributes=extension_attributes, text=text) def BatchStatusFromString(xml_string): return atom.CreateClassFromXMLString(BatchStatus, xml_string) class BatchEntry(GDataEntry): """An atom:entry for use in batch requests. The BatchEntry contains additional members to specify the operation to be performed on this entry and a batch ID so that the server can reference individual operations in the response feed. For more information, see: http://code.google.com/apis/gdata/batch.html """ _tag = GDataEntry._tag _namespace = GDataEntry._namespace _children = GDataEntry._children.copy() _children['{%s}operation' % BATCH_NAMESPACE] = ('batch_operation', BatchOperation) _children['{%s}id' % BATCH_NAMESPACE] = ('batch_id', BatchId) _children['{%s}status' % BATCH_NAMESPACE] = ('batch_status', BatchStatus) _attributes = GDataEntry._attributes.copy() def __init__(self, author=None, category=None, content=None, contributor=None, atom_id=None, link=None, published=None, rights=None, source=None, summary=None, control=None, title=None, updated=None, batch_operation=None, batch_id=None, batch_status=None, extension_elements=None, extension_attributes=None, text=None): self.batch_operation = batch_operation self.batch_id = batch_id self.batch_status = batch_status GDataEntry.__init__(self, author=author, category=category, content=content, contributor=contributor, atom_id=atom_id, link=link, published=published, rights=rights, source=source, summary=summary, control=control, title=title, updated=updated, extension_elements=extension_elements, extension_attributes=extension_attributes, text=text) def BatchEntryFromString(xml_string): return atom.CreateClassFromXMLString(BatchEntry, xml_string) class BatchInterrupted(atom.AtomBase): """The batch:interrupted element sent if batch request was interrupted. Only appears in a feed if some of the batch entries could not be processed. See: http://code.google.com/apis/gdata/batch.html#Handling_Errors """ _tag = 'interrupted' _namespace = BATCH_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() _attributes['reason'] = 'reason' _attributes['success'] = 'success' _attributes['failures'] = 'failures' _attributes['parsed'] = 'parsed' def __init__(self, reason=None, success=None, failures=None, parsed=None, extension_elements=None, extension_attributes=None, text=None): self.reason = reason self.success = success self.failures = failures self.parsed = parsed atom.AtomBase.__init__(self, extension_elements=extension_elements, extension_attributes=extension_attributes, text=text) def BatchInterruptedFromString(xml_string): return atom.CreateClassFromXMLString(BatchInterrupted, xml_string) class BatchFeed(GDataFeed): """A feed containing a list of batch request entries.""" _tag = GDataFeed._tag _namespace = GDataFeed._namespace _children = GDataFeed._children.copy() _attributes = GDataFeed._attributes.copy() _children['{%s}entry' % atom.ATOM_NAMESPACE] = ('entry', [BatchEntry]) _children['{%s}interrupted' % BATCH_NAMESPACE] = ('interrupted', BatchInterrupted) def __init__(self, author=None, category=None, contributor=None, generator=None, icon=None, atom_id=None, link=None, logo=None, rights=None, subtitle=None, title=None, updated=None, entry=None, total_results=None, start_index=None, items_per_page=None, interrupted=None, extension_elements=None, extension_attributes=None, text=None): self.interrupted = interrupted GDataFeed.__init__(self, author=author, category=category, contributor=contributor, generator=generator, icon=icon, atom_id=atom_id, link=link, logo=logo, rights=rights, subtitle=subtitle, title=title, updated=updated, entry=entry, total_results=total_results, start_index=start_index, items_per_page=items_per_page, extension_elements=extension_elements, extension_attributes=extension_attributes, text=text) def AddBatchEntry(self, entry=None, id_url_string=None, batch_id_string=None, operation_string=None): """Logic for populating members of a BatchEntry and adding to the feed. If the entry is not a BatchEntry, it is converted to a BatchEntry so that the batch specific members will be present. The id_url_string can be used in place of an entry if the batch operation applies to a URL. For example query and delete operations require just the URL of an entry, no body is sent in the HTTP request. If an id_url_string is sent instead of an entry, a BatchEntry is created and added to the feed. This method also assigns the desired batch id to the entry so that it can be referenced in the server's response. If the batch_id_string is None, this method will assign a batch_id to be the index at which this entry will be in the feed's entry list. Args: entry: BatchEntry, atom.Entry, or another Entry flavor (optional) The entry which will be sent to the server as part of the batch request. The item must have a valid atom id so that the server knows which entry this request references. id_url_string: str (optional) The URL of the entry to be acted on. You can find this URL in the text member of the atom id for an entry. If an entry is not sent, this id will be used to construct a new BatchEntry which will be added to the request feed. batch_id_string: str (optional) The batch ID to be used to reference this batch operation in the results feed. If this parameter is None, the current length of the feed's entry array will be used as a count. Note that batch_ids should either always be specified or never, mixing could potentially result in duplicate batch ids. operation_string: str (optional) The desired batch operation which will set the batch_operation.type member of the entry. Options are 'insert', 'update', 'delete', and 'query' Raises: MissingRequiredParameters: Raised if neither an id_ url_string nor an entry are provided in the request. Returns: The added entry. """ if entry is None and id_url_string is None: raise MissingRequiredParameters('supply either an entry or URL string') if entry is None and id_url_string is not None: entry = BatchEntry(atom_id=atom.Id(text=id_url_string)) # TODO: handle cases in which the entry lacks batch_... members. #if not isinstance(entry, BatchEntry): # Convert the entry to a batch entry. if batch_id_string is not None: entry.batch_id = BatchId(text=batch_id_string) elif entry.batch_id is None or entry.batch_id.text is None: entry.batch_id = BatchId(text=str(len(self.entry))) if operation_string is not None: entry.batch_operation = BatchOperation(op_type=operation_string) self.entry.append(entry) return entry def AddInsert(self, entry, batch_id_string=None): """Add an insert request to the operations in this batch request feed. If the entry doesn't yet have an operation or a batch id, these will be set to the insert operation and a batch_id specified as a parameter. Args: entry: BatchEntry The entry which will be sent in the batch feed as an insert request. batch_id_string: str (optional) The batch ID to be used to reference this batch operation in the results feed. If this parameter is None, the current length of the feed's entry array will be used as a count. Note that batch_ids should either always be specified or never, mixing could potentially result in duplicate batch ids. """ entry = self.AddBatchEntry(entry=entry, batch_id_string=batch_id_string, operation_string=BATCH_INSERT) def AddUpdate(self, entry, batch_id_string=None): """Add an update request to the list of batch operations in this feed. Sets the operation type of the entry to insert if it is not already set and assigns the desired batch id to the entry so that it can be referenced in the server's response. Args: entry: BatchEntry The entry which will be sent to the server as an update (HTTP PUT) request. The item must have a valid atom id so that the server knows which entry to replace. batch_id_string: str (optional) The batch ID to be used to reference this batch operation in the results feed. If this parameter is None, the current length of the feed's entry array will be used as a count. See also comments for AddInsert. """ entry = self.AddBatchEntry(entry=entry, batch_id_string=batch_id_string, operation_string=BATCH_UPDATE) def AddDelete(self, url_string=None, entry=None, batch_id_string=None): """Adds a delete request to the batch request feed. This method takes either the url_string which is the atom id of the item to be deleted, or the entry itself. The atom id of the entry must be present so that the server knows which entry should be deleted. Args: url_string: str (optional) The URL of the entry to be deleted. You can find this URL in the text member of the atom id for an entry. entry: BatchEntry (optional) The entry to be deleted. batch_id_string: str (optional) Raises: MissingRequiredParameters: Raised if neither a url_string nor an entry are provided in the request. """ entry = self.AddBatchEntry(entry=entry, id_url_string=url_string, batch_id_string=batch_id_string, operation_string=BATCH_DELETE) def AddQuery(self, url_string=None, entry=None, batch_id_string=None): """Adds a query request to the batch request feed. This method takes either the url_string which is the query URL whose results will be added to the result feed. The query URL will be encapsulated in a BatchEntry, and you may pass in the BatchEntry with a query URL instead of sending a url_string. Args: url_string: str (optional) entry: BatchEntry (optional) batch_id_string: str (optional) Raises: MissingRequiredParameters """ entry = self.AddBatchEntry(entry=entry, id_url_string=url_string, batch_id_string=batch_id_string, operation_string=BATCH_QUERY) def GetBatchLink(self): for link in self.link: if link.rel == 'http://schemas.google.com/g/2005#batch': return link return None def BatchFeedFromString(xml_string): return atom.CreateClassFromXMLString(BatchFeed, xml_string) class EntryLink(atom.AtomBase): """The gd:entryLink element""" _tag = 'entryLink' _namespace = GDATA_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() # The entry used to be an atom.Entry, now it is a GDataEntry. _children['{%s}entry' % atom.ATOM_NAMESPACE] = ('entry', GDataEntry) _attributes['rel'] = 'rel' _attributes['readOnly'] = 'read_only' _attributes['href'] = 'href' def __init__(self, href=None, read_only=None, rel=None, entry=None, extension_elements=None, extension_attributes=None, text=None): self.href = href self.read_only = read_only self.rel = rel self.entry = entry self.text = text self.extension_elements = extension_elements or [] self.extension_attributes = extension_attributes or {} def EntryLinkFromString(xml_string): return atom.CreateClassFromXMLString(EntryLink, xml_string) class FeedLink(atom.AtomBase): """The gd:feedLink element""" _tag = 'feedLink' _namespace = GDATA_NAMESPACE _children = atom.AtomBase._children.copy() _attributes = atom.AtomBase._attributes.copy() _children['{%s}feed' % atom.ATOM_NAMESPACE] = ('feed', GDataFeed) _attributes['rel'] = 'rel' _attributes['readOnly'] = 'read_only' _attributes['countHint'] = 'count_hint' _attributes['href'] = 'href' def __init__(self, count_hint=None, href=None, read_only=None, rel=None, feed=None, extension_elements=None, extension_attributes=None, text=None): self.count_hint = count_hint self.href = href self.read_only = read_only self.rel = rel self.feed = feed self.text = text self.extension_elements = extension_elements or [] self.extension_attributes = extension_attributes or {} def FeedLinkFromString(xml_string): return atom.CreateClassFromXMLString(FeedLink, xml_string)