Handle items that should appear in more than one group

For example, when grouping by project, a todo item in two groups will be
added to each applicable project.

topydo/lib/Sorter.py

@@ -16,6 +16,7 @@
 
 """ This module provides functionality to sort lists with todo items. """
 
+from collections import OrderedDict
 from itertools import groupby
 import re
 from datetime import date
@@ -34,33 +35,14 @@ def get_field_function(p_field):
     access that property. If the property could not be located, return the
     identity function.
     """
-
-    def priority_key(p_todo):
-        priority = p_todo.priority()
-        return (priority or 'ZZ', priority or '')
-
-    def projects_key(p_todo):
-        projects = sorted(p_todo.projects())
-        return ([p.lower() for p in projects], ", ".join(projects))
-
-    def contexts_key(p_todo):
-        contexts = sorted(p_todo.contexts())
-        return ([p.lower() for p in contexts], ", ".join(contexts))
-
-    def get_tag_key(p_todo):
-        if p_todo.has_tag(p_field):
-            return ("0" + p_todo.tag_value(p_field), p_todo.tag_value(p_field))
-        else:
-            return ("1", "")
-
     # default result
     result = lambda a: a
 
     if is_priority_field(p_field):
         # assign dummy priority when a todo has no priority
-        result = priority_key
+        result = lambda a: a.priority() or 'ZZ'
     elif p_field == 'context' or p_field == 'contexts':
-        result = contexts_key
+        result = lambda a: sorted([c.lower() for c in a.contexts()])
     elif p_field == 'creationdate' or p_field == 'creation':
         # when a task has no creation date, push it to the end by assigning it
         # the maximum possible date.
@@ -76,14 +58,15 @@ def get_field_function(p_field):
     elif p_field == 'length':
         result = lambda a: a.length()
     elif p_field == 'project' or p_field == 'projects':
-        result = projects_key
+        result = lambda a: sorted([c.lower() for c in a.projects()])
     elif p_field == 'text':
         result = lambda a: a.text()
     else:
         # try to find the corresponding tag
         # when a tag is not present, push it to the end of the list by giving
         # it an artificially higher value
-        result = get_tag_key
+        result = (lambda a: "0" + a.tag_value(p_field) if a.has_tag(p_field)
+                  else "1")
 
     return result
 
@@ -138,17 +121,25 @@ class Sorter(object):
         Groups the todos according to the given group string. Assumes that the
         given todos have already been sorted with self.sort().
         """
-        result = [([], p_todos)]
+        result = OrderedDict([((), p_todos)])
 
         for function, _ in self.groupfunctions:
             oldresult = result
-            result = []
-            for oldkey, oldgroup in oldresult:
+            result = OrderedDict()
+            for oldkey, oldgroup in oldresult.items():
                 for key, group in groupby(oldgroup, function):
-                    newkey = oldkey + [key]
                     newgroup = list(group)
 
-                    result.append((newkey, newgroup))
+                    if not isinstance(key, list):
+                        key = [key]
+
+                    for subkey in key:
+                        newkey = oldkey + (subkey,)
+
+                        if newkey in result:
+                            result[newkey] = result[newkey] + newgroup
+                        else:
+                            result[newkey] = newgroup
 
         return result
 
@@ -191,12 +182,12 @@ if __name__ == '__main__':
         Todo('Foo +A @A type:a'),
         Todo('Foo +A @B type:b'),
         Todo('Bar +B @B type:b'),
-        Todo('Baz +A @B'),
+        Todo('Baz +A +B @B'),
     ]
 
     s = Sorter('desc:context', 'project,type')
 
-    for key, group in s.group(todos):
+    for key, group in s.group(todos).items():
         print(key)
         for item2 in group:
             print(item2.source())

topydo/lib/printers/PrettyPrinter.py

@@ -79,7 +79,7 @@ class PrettyPrinter(Printer):
     def print_groups(self, p_groups):
         result = []
 
-        for key, todos in p_groups:
+        for key, todos in p_groups.items():
             result.append(TopydoString(''))
             result.append(TopydoString(key))
             result.append(TopydoString("==="))