Add ability to identify tasks based on their UID.

bin/topydo.conf

@@ -6,6 +6,7 @@ default_command             = ls
 ; archive_filename          = done.txt
 colors                      = 1
 highlight_projects_contexts = 1
+identifiers                 = linenumber ; or: text
 
 [ls]
 indent                      = 0

test/SortCommandTest.py

@@ -15,6 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import CommandTest
+from Config import config
 import SortCommand
 import TestFacilities
 
@@ -22,6 +23,10 @@ class SortCommandTest(CommandTest.CommandTest):
     def setUp(self):
         self.todolist = TestFacilities.load_file_to_todolist("data/SorterTest1.txt")
 
+    def tearDown(self):
+        # restore to the default configuration in case a custom one was set
+        config("")
+
     def test_sort1(self):
         """ Alphabetically sorted """
         command = SortCommand.SortCommand(["text"], self.todolist, self.out, self.error)
@@ -35,6 +40,17 @@ class SortCommandTest(CommandTest.CommandTest):
 
         self.assertEquals(str(self.todolist), "(A) Foo\n2014-06-14 Last\nFirst")
 
+    def test_sort3(self):
+        """ Check that order does not influence the UID of a todo. """
+        config("data/todolist-uid.conf")
+
+        todo1 = self.todolist.todo('tpi')
+        command = SortCommand.SortCommand(["text"], self.todolist, self.out, self.error)
+        command.execute()
+        todo2 = self.todolist.todo('tpi')
+
+        self.assertEquals(todo1.source(), todo2.source())
+
     def test_help(self):
         command = SortCommand.SortCommand(["help"], self.todolist, self.out, self.error)
         command.execute()

test/TodoListTest.py

@@ -19,6 +19,7 @@
 import re
 import unittest
 
+from Config import config
 import Todo
 import TodoFile
 from TodoListBase import InvalidTodoException
@@ -32,6 +33,10 @@ class TodoListTester(unittest.TestCase):
         self.text = ''.join(lines)
         self.todolist = TodoList.TodoList(lines)
 
+    def tearDown(self):
+        # restore to the default configuration in case a custom one was set
+        config("")
+
     def test_contexts(self):
         self.assertEquals(set(['Context1', 'Context2']), \
             self.todolist.contexts())
@@ -191,6 +196,19 @@ class TodoListTester(unittest.TestCase):
         self.assertTrue(todo)
         self.assertEquals(todo.source(), "(D) Bar @Context1 +Project2")
 
+    def test_uid1(self):
+        config("data/todolist-uid.conf")
+
+        self.assertEquals(self.todolist.todo('6iu').source(), "(C) Foo @Context2 Not@Context +Project1 Not+Project")
+
+    def test_uid2(self):
+        """ Changing the priority should not change the identifier. """
+        config("data/todolist-uid.conf")
+
+        todo = self.todolist.todo('6iu')
+        self.todolist.set_priority(todo, 'B')
+        self.assertEquals(self.todolist.todo('6iu').source(), "(B) Foo @Context2 Not@Context +Project1 Not+Project")
+
 class TodoListDependencyTester(unittest.TestCase):
     def setUp(self):
         self.todolist = TodoList.TodoList([])

test/data/todolist-uid.conf

+[topydo]
+identifiers = text

topydo/lib/Config.py

@@ -36,6 +36,7 @@ class _Config:
             'highlight_projects_contexts': '1',
             'filename' : 'todo.txt',
             'archive_filename' : 'done.txt',
+            'identifiers': 'linenumber',
 
             # ls
             'indent': 0,
@@ -93,6 +94,9 @@ class _Config:
     def archive(self):
         return self.cp.get('topydo', 'archive_filename')
 
+    def identifiers(self):
+        return self.cp.get('topydo', 'identifiers')
+
     def list_limit(self):
         try:
             return self.cp.getint('ls', 'list_limit')

topydo/lib/TodoListBase.py

@@ -21,6 +21,7 @@ A list of todo items.
 from datetime import date
 import re
 
+from Config import config
 import Filter
 from HashListValues import hash_list_values
 from PrettyPrinter import pretty_print_list
@@ -56,13 +57,23 @@ class TodoListBase(object):
         The _todos list has the same order as in the backend store (usually
         a todo.txt file. The user refers to the first task as number 1, so use
         index 0, etc.
+
+        Alternative ways to identify a todo is using a hashed version based on
+        the todo's text, or a regexp that matches the todo's source. The regexp
+        match is a fallback.
+
+        Returns None when the todo couldn't be found.
         """
         result = None
+
         try:
-            result = self._todos[int(p_identifier) - 1]
+            if config().identifiers() == 'text':
+                result = self._id_todo_map[p_identifier]
+            else:
+                result = self._todos[int(p_identifier) - 1]
         except IndexError:
             raise InvalidTodoException
-        except (TypeError, ValueError):
+        except (TypeError, ValueError, KeyError):
             result = self.todo_by_regexp(p_identifier)
 
         return result