Task: Use empty string as replacement for None when saving the task

[etc/taskwarrior.git] / tasklib / task.py

diff --git a/tasklib/task.py b/tasklib/task.py
index 44c6965c1e3fdde7be836e48a4f8befb7f9a38c8..4377f1fb8f1737d730a7cb782c1a2d5f74ba3cd6 100644 (file)
--- a/tasklib/task.py
+++ b/tasklib/task.py
@@ -34,6 +34,14 @@ class TaskResource(object):
         self._original_data = data.copy()
 
     def __getitem__(self, key):
+        # This is a workaround to make TaskResource non-iterable
+        # over simple index-based iteration
+        try:
+            int(key)
+            raise StopIteration
+        except ValueError:
+            pass
+
         hydrate_func = getattr(self, 'deserialize_{0}'.format(key),
                                lambda x: x)
         return hydrate_func(self._data.get(key))
@@ -114,10 +122,21 @@ class Task(TaskResource):
         return self['description']
 
     def __eq__(self, other):
-        return self['uuid'] == other['uuid']
+        if self['uuid'] and other['uuid']:
+            # For saved Tasks, just define equality by equality of uuids
+            return self['uuid'] == other['uuid']
+        else:
+            # If the tasks are not saved, compare the actual instances
+            return id(self) == id(other)
+
 
     def __hash__(self):
-        return self['uuid'].__hash__()
+        if self['uuid']:
+            # For saved Tasks, just define equality by equality of uuids
+            return self['uuid'].__hash__()
+        else:
+            # If the tasks are not saved, return hash of instance id
+            return id(self).__hash__()
 
     @property
     def _modified_fields(self):
@@ -153,6 +172,41 @@ class Task(TaskResource):
             return None
         return datetime.datetime.strptime(date_str, DATE_FORMAT)
 
+    def serialize_depends(self, cur_dependencies):
+        # Check that all the tasks are saved
+        for task in cur_dependencies:
+            if not task.saved:
+                raise Task.NotSaved('Task \'%s\' needs to be saved before '
+                                    'it can be set as dependency.' % task)
+
+        # Return the list of uuids
+        return ','.join(task['uuid'] for task in cur_dependencies)
+
+    def deserialize_depends(self, raw_uuids):
+        raw_uuids = raw_uuids or ''  # Convert None to empty string
+        uuids = raw_uuids.split(',')
+        return set(self.warrior.tasks.get(uuid=uuid) for uuid in uuids if uuid)
+
+    def format_depends(self):
+        # We need to generate added and removed dependencies list,
+        # since Taskwarrior does not accept redefining dependencies.
+
+        # This cannot be part of serialize_depends, since we need
+        # to keep a list of all depedencies in the _data dictionary,
+        # not just currently added/removed ones
+
+        old_dependencies_raw = self._original_data.get('depends','')
+        old_dependencies = self.deserialize_depends(old_dependencies_raw)
+
+        added = self['depends'] - old_dependencies
+        removed = old_dependencies - self['depends']
+
+        # Removed dependencies need to be prefixed with '-'
+        return ','.join(
+                [t['uuid'] for t in added] +
+                ['-' + t['uuid'] for t in removed]
+            )
+
     def deserialize_annotations(self, data):
         return [TaskAnnotation(self, d) for d in data] if data else []
 
@@ -245,8 +299,11 @@ class Task(TaskResource):
             # task description if description: prefix is used
             if self.warrior.version < VERSION_2_4_0 and field == 'description':
                 args.append(self._data[field])
+            elif field == 'depends':
+                args.append('{0}:{1}'.format(field, self.format_depends()))
             else:
-                args.append('{0}:{1}'.format(field, self._data[field]))
+                # Use empty string to substitute for None value
+                args.append('{0}:{1}'.format(field, self._data[field] or ''))
 
         # If we're modifying saved task, simply pass on all modified fields
         if self.saved: