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 bb3fa537438250a7153f3aa214138bbba65819dc..4377f1fb8f1737d730a7cb782c1a2d5f74ba3cd6 100644 (file)
--- a/tasklib/task.py
+++ b/tasklib/task.py
@@ -29,8 +29,19 @@ class TaskResource(object):
 
     def _load_data(self, data):
         self._data = data
+        # We need to use a copy for original data, so that changes
+        # are not propagated
+        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))
@@ -41,7 +52,6 @@ class TaskResource(object):
         dehydrate_func = getattr(self, 'serialize_{0}'.format(key),
                                  lambda x: x)
         self._data[key] = dehydrate_func(value)
-        self._modified_fields.add(key)
 
     def __str__(self):
         s = six.text_type(self.__unicode__())
@@ -107,11 +117,33 @@ class Task(TaskResource):
         kwargs.update(data)
 
         self._load_data(kwargs)
-        self._modified_fields = set()
 
     def __unicode__(self):
         return self['description']
 
+    def __eq__(self, other):
+        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):
+        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):
+        for key in self._data.keys():
+            if self._data.get(key) != self._original_data.get(key):
+                yield key
+
     @property
     def completed(self):
         return self['status'] == six.text_type('completed')
@@ -140,6 +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 []
 
@@ -204,7 +271,6 @@ class Task(TaskResource):
             # Circumvent the ID storage, since ID is considered read-only
             self._data['id'] = int(id_lines[0].split(' ')[2].rstrip('.'))
 
-        self._modified_fields.clear()
         self.refresh()
 
     def add_annotation(self, annotation):
@@ -233,8 +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:
@@ -263,8 +332,13 @@ class Task(TaskResource):
             to_update = dict(
                 [(k, new_data.get(k)) for k in only_fields])
             self._data.update(to_update)
+            self._original_data.update(to_update)
         else:
             self._data = new_data
+            # We need to create a clone for original_data though
+            # Shallow copy is alright, since data dict uses only
+            # primitive data types
+            self._original_data = new_data.copy()
 
 
 class TaskFilter(object):