Introduce MultiCommand.execute() and execute_multi_specific()

Commands operating on multiple todos will inherit common execute()
method from MultiCommand class, and part specific for each command will
be covered in execute_multi_specific()

topydo/lib/DCommand.py

@@ -129,13 +129,7 @@ class DCommand(MultiCommand):
         """
         pass
 
-    def execute(self):
-        if not super(DCommand, self).execute():
-            return False
-
-        todo_errors = self.catch_todo_errors()
-
-        if not todo_errors:
+    def execute_multi_specific(self):
         old_active = self._active_todos()
 
         for todo in self.todos:
@@ -147,6 +141,3 @@ class DCommand(MultiCommand):
 
         current_active = self._active_todos()
         self._print_unlocked_todos(old_active, current_active)
-        else:
-            for error in todo_errors:
-                self.error(error)

topydo/lib/MultiCommand.py

@@ -40,7 +40,7 @@ class MultiCommand(Command):
             except InvalidTodoException:
                 self.invalid_numbers.append(number)
 
-    def catch_todo_errors(self):
+    def _catch_todo_errors(self):
         """
         Returns None or list of error messages depending on number of valid todo
         objects and number of invalid todo IDs.
@@ -62,3 +62,22 @@ class MultiCommand(Command):
             return errors
         else:
             return None
+
+    def execute_multi_specific(self):
+        """
+        Operations specific for particular command dealing with multiple todo
+        IDs.
+        """
+        pass
+
+    def execute(self):
+        if not super(MultiCommand, self).execute():
+            return False
+
+        todo_errors = self._catch_todo_errors()
+
+        if not todo_errors:
+            self.execute_multi_specific()
+        else:
+            for error in todo_errors:
+                self.error(error)

topydo/lib/PostponeCommand.py

@@ -45,7 +45,7 @@ class PostponeCommand(MultiCommand):
 
         self.args = args
 
-    def execute(self):
+    def execute_multi_specific(self):
         def _get_offset(p_todo):
             offset = p_todo.tag_value(
                 config().tag_due(), date.today().isoformat())
@@ -56,12 +56,6 @@ class PostponeCommand(MultiCommand):
 
             return offset_date
 
-        if not super(PostponeCommand, self).execute():
-            return False
-
-        todo_errors = self.catch_todo_errors()
-
-        if not todo_errors:
         try:
             pattern = self.args[-1]
             self.printer.add_filter(PrettyPrinterNumbers(self.todolist))
@@ -85,9 +79,6 @@ class PostponeCommand(MultiCommand):
                     break
         except (InvalidCommandArgument, IndexError):
             self.error(self.usage())
-        else:
-            for error in todo_errors:
-                self.error(error)
 
     def usage(self):
         return "Synopsis: postpone [-s] <NUMBER> [<NUMBER2> ...] <PATTERN>"

topydo/lib/PriorityCommand.py

@@ -29,14 +29,9 @@ class PriorityCommand(MultiCommand):
 
         self.get_todos(self.args[:-1])
 
-    def execute(self):
-        if not super(PriorityCommand, self).execute():
-            return False
-
+    def execute_multi_specific(self):
         priority = None
-        todo_errors = self.catch_todo_errors()
 
-        if not todo_errors:
         try:
             priority = self.args[-1]
             self.printer.add_filter(PrettyPrinterNumbers(self.todolist))
@@ -57,9 +52,6 @@ class PriorityCommand(MultiCommand):
                 self.error("Invalid priority given.")
         except IndexError:
             self.error(self.usage())
-        else:
-            for error in todo_errors:
-                self.error(error)
 
     def usage(self):
         return """Synopsis: pri <NUMBER1> [<NUMBER2> ...] <PRIORITY>"""