--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/soc/logic/document.py	Sat Sep 13 22:00:51 2008 +0000
@@ -0,0 +1,85 @@
+#!/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.
+
+"""Document (Model) query functions.
+"""
+
+__authors__ = [
+  '"Pawel Solyga" <pawel.solyga@gmail.com>',
+  ]
+
+from google.appengine.ext import db
+
+import soc.models.document
+import soc.logic.model
+
+def getDocumentFromPath(path):
+  """Returns Document entity for a given path, or None if not found.  
+    
+  Args:
+    id: a Google Account (users.User) object
+  """
+  # lookup by Doc:path key name
+  key_name = getDocumentKeyNameForPath(path)
+  
+  if key_name:
+    document = soc.models.document.Document.get_by_key_name(key_name)
+  else:
+    document = None
+  
+  return document
+
+def getDocumentKeyNameForPath(path):
+  """Return a Datastore key_name for a Document from the path.
+  
+  Args:
+    path: a request path of the Document that uniquely identifies it
+  """
+  if not path:
+    return None
+
+  return 'Doc:%s' % path
+
+
+def updateOrCreateDocumentFromPath(path, **document_properties):
+  """Update existing Document entity, or create new one with supplied properties.
+
+  Args:
+    path: a request path of the Document that uniquely identifies it
+    **document_properties: keyword arguments that correspond to Document entity
+      properties and their values
+
+  Returns:
+    the Document entity corresponding to the path, with any supplied
+    properties changed, or a new Document entity now associated with the 
+    supplied path and properties.
+  """
+  # attempt to retrieve the existing Document
+  document = getDocumentFromPath(path)
+
+  if not document:
+    # document did not exist, so create one in a transaction
+    key_name = getDocumentKeyNameForPath(path)
+    document = soc.models.document.Document.get_or_insert(
+      key_name, **document_properties)
+
+  # there is no way to be sure if get_or_insert() returned a new Document or
+  # got an existing one due to a race, so update with document_properties anyway,
+  # in a transaction
+  return soc.logic.model.updateModelProperties(document, **document_properties)
+
+
+