--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/soc/logic/lists.py	Fri Nov 21 23:45:37 2008 +0000
@@ -0,0 +1,134 @@
+#!/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.
+
+"""List generation logic
+"""
+
+__authors__ = [
+  '"Sverre Rabbelier" <sverre@rabbelier.nl>',
+  ]
+
+
+class Lists(object):
+  """List array suitable for enumerating over with just 'for in'
+  """
+
+  DEF_PASSTHROUGH_FIELDS = [
+      'pagination',
+      'description',
+      'heading',
+      'row',
+      'limit',
+      'newest',
+      'prev',
+      'next',
+      'first',
+      'last',
+      ]
+
+  def __init__(self, contents):
+    """Constructs a new Lists object with the specified contents
+    """
+
+    # All the contents of all the lists
+    self.contents = contents
+    self.content = {}
+
+    # For iterating over all the lists
+    self.lists = range(len(contents))
+    self.list_data = []
+
+    # For iterating over the rows
+    self.rows = []
+    self.row_data = []
+
+  def __getattr__(self, attr):
+    """Delegate field lookup to the current list if appropriate
+
+    If, and only if, a lookup is done on one of the fields defined in
+    DEF_PASSTHROUGH_FIELDS, and the current list defines this field,
+    the value from the current list is returned.
+    """
+
+    if attr not in self.DEF_PASSTHROUGH_FIELDS:
+      raise AttributeError()
+
+    if attr not in self.content:
+      raise AttributeError()
+
+    return self.get(attr)
+
+  def get(self, item):
+    """Returns the item for the current list data
+    """
+
+    return self.content[item]
+
+  def next_list(self):
+    """Shifts out the current list content
+
+    The main content of the next list is returned for further processing.
+    """
+
+    # Advance the list data once
+    self.content = self.contents[0]
+    self.contents = self.contents[1:]
+
+    # Update internal 'iterators'
+    self.list_data = self.get('data')
+    self.rows = range(len(self.list_data))
+
+    return self.get('main')
+
+  def next_row(self):
+    """Returns the next list row for the current list
+
+    Before calling this method, next_list should be called at least once.
+    """
+
+    # Update internal 'iterators'
+    self.row_data =  self.list_data[0]
+
+    # Advance the row data once
+    self.list_data = self.list_data[1:]
+
+    return self.get('row')
+
+  def lists(self):
+    """Returns a list of numbers the size of the amount of lists.
+
+    This method can be used to iterate over all lists with shift,
+    without using a while loop.
+    """
+
+    return self.lists
+
+  def rows(self):
+    """Returns a list of numbers the size of the amount of items.
+
+    This method can be used to iterate over all items with next for
+    the current list, without using a while loop.
+    """
+
+    return self.rows
+
+  def item(self):
+    """Returns the current row item for the current list
+
+    Before calling this method, next_row should be called at least once.
+    """
+
+    return self.row_data