Add method to set the todos creation date.

TodoBase.py

@@ -179,6 +179,21 @@ class TodoBase(object):
             self.src = re.sub(r'^(\([A-Z]\) )?', \
                 'x ' + today.isoformat() + ' ', self.src)
 
+    def set_creation_date(self, date):
+        """
+        Sets the creation date of a todo. Should be passed a date object.
+        """
+        self.fields['creationDate'] = date
+
+        # not particulary pretty, but inspired by
+        # http://bugs.python.org/issue1519638 non-existent matches trigger
+        # exceptions, hence the lambda
+        self.src = re.sub(
+            r'^(x \d{4}-\d{2}-\d{2} |\([A-Z]\) )?(\d{4}-\d{2}-\d{2} )?(.*)$', \
+            lambda m: \
+            "%s%s %s" % (m.group(1) or '', date.isoformat(), m.group(3)), \
+            self.src)
+
     def creation_date(self):
         """ Returns the creation date of a todo. """
         return self.fields['creationDate']

test/TodoBaseTest.py

@@ -228,5 +228,50 @@ class TodoBaseTester(unittest.TestCase):
         self.assertEquals(todo.src, new_text)
         self.assertEquals(todo.priority(),'C')
 
+    def test_set_creation_date1(self):
+        todo = TodoBase.TodoBase("Foo")
+        date = datetime.date(2014, 7, 24)
+
+        todo.set_creation_date(date)
+
+        self.assertEquals(todo.creation_date(), date)
+        self.assertEquals(todo.src, "2014-07-24 Foo")
+
+    def test_set_creation_date2(self):
+        todo = TodoBase.TodoBase("(A) Foo")
+        date = datetime.date(2014, 7, 24)
+
+        todo.set_creation_date(date)
+
+        self.assertEquals(todo.creation_date(), date)
+        self.assertEquals(todo.src, "(A) 2014-07-24 Foo")
+
+    def test_set_creation_date3(self):
+        todo = TodoBase.TodoBase("(A) 2014-07-23 Foo")
+        date = datetime.date(2014, 7, 24)
+
+        todo.set_creation_date(date)
+
+        self.assertEquals(todo.creation_date(), date)
+        self.assertEquals(todo.src, "(A) 2014-07-24 Foo")
+
+    def test_set_creation_date4(self):
+        todo = TodoBase.TodoBase("2014-07-23 Foo")
+        date = datetime.date(2014, 7, 24)
+
+        todo.set_creation_date(date)
+
+        self.assertEquals(todo.creation_date(), date)
+        self.assertEquals(todo.src, "2014-07-24 Foo")
+
+    def test_set_creation_date5(self):
+        todo = TodoBase.TodoBase("x 2014-07-25 2014-07-23 Foo")
+        date = datetime.date(2014, 7, 24)
+
+        todo.set_creation_date(date)
+
+        self.assertEquals(todo.creation_date(), date)
+        self.assertEquals(todo.src, "x 2014-07-25 2014-07-24 Foo")
+
 if __name__ == '__main__':
     unittest.main()