Merge pull request #57 from coddingtonbear/only_change_if_changes_exi…

…st_when_using_modern_task

Only attempt to change fields known to have changed if using new journal...

taskw/task.py

@@ -171,6 +171,15 @@ def serialized(self):
             serialized[k] = self._serialize(k, v)
         return serialized
 
+    def serialized_changes(self, keep=False):
+        serialized = {}
+        for k, v in six.iteritems(self.get_changes(keep=keep)):
+            # Here, `v` is a 2-tuple of the field's original value
+            # and the field's new value.
+            _, to = v
+            serialized[k] = self._serialize(k, to)
+        return serialized
+
     def __getitem__(self, key):
         try:
             return super(Task, self).__getitem__(key)

taskw/warrior.py

@@ -706,12 +706,19 @@ def task_done(self, **kw):
     def task_update(self, task):
         if 'uuid' not in task:
             raise KeyError('Task must have a UUID.')
+        # 'Legacy' causes us to handle this task as if it were an
+        # old-style task -- just a standard dictionary
+        legacy = True
 
         if isinstance(task, Task):
             # Let's pre-serialize taskw.task.Task instances
-            task = task.serialized()
+            task_uuid = six.text_type(task['uuid'])
+            task = task.serialized_changes(keep=True)
+            legacy = False
+        else:
+            task_uuid = task['uuid']
 
-        id, original_task = self.get_task(uuid=task['uuid'])
+        id, original_task = self.get_task(uuid=task_uuid)
 
         if 'id' in task:
             del task['id']
@@ -721,35 +728,52 @@ def task_update(self, task):
         task_to_modify.pop('uuid', None)
         task_to_modify.pop('id', None)
 
-        # Check if there are annotations, if so, look if they are
-        # in the existing task, otherwise annotate the task to add them.
-        ttm_annotations = taskw.utils.annotation_list_to_comparison_map(
-            self._extract_annotations_from_task(task_to_modify)
-        )
-        original_annotations = taskw.utils.annotation_list_to_comparison_map(
-            self._extract_annotations_from_task(original_task)
-        )
+        # Only handle annotation differences if this is an old-style
+        # task, or if the task itself says annotations have changed.
+        annotations_to_delete = set()
+        annotations_to_create = set()
+        if legacy or 'annotations' in task_to_modify:
+            # Check if there are annotations, if so, look if they are
+            # in the existing task, otherwise annotate the task to add them.
+            ttm_annotations = taskw.utils.annotation_list_to_comparison_map(
+                self._extract_annotations_from_task(task_to_modify)
+            )
+            original_annotations = (
+                taskw.utils.annotation_list_to_comparison_map(
+                    self._extract_annotations_from_task(original_task)
+                )
+            )
 
-        new_annotations = set(ttm_annotations.keys())
-        existing_annotations = set(original_annotations.keys())
+            new_annotations = set(ttm_annotations.keys())
+            existing_annotations = set(original_annotations.keys())
 
-        annotations_to_delete = existing_annotations - new_annotations
-        annotations_to_create = new_annotations - existing_annotations
+            annotations_to_delete = existing_annotations - new_annotations
+            annotations_to_create = new_annotations - existing_annotations
 
-        if 'annotations' in task_to_modify:
-            del task_to_modify['annotations']
+            if 'annotations' in task_to_modify:
+                del task_to_modify['annotations']
 
         modification = taskw.utils.encode_task_experimental(task_to_modify)
-        self._execute(task['uuid'], 'modify', modification)
+        # Only try to modify the task if there are changes to post here
+        # (changes *might* just be in annotations).
+        if modification.strip():
+            self._execute(task_uuid, 'modify', modification)
 
         # If there are no existing annotations, add the new ones
-        ttm_annotations.update(original_annotations)
-        for annotation_key in annotations_to_create:
-            self.task_annotate(original_task, ttm_annotations[annotation_key])
-        for annotation_key in annotations_to_delete:
-            self.task_denotate(original_task, ttm_annotations[annotation_key])
+        if legacy or annotations_to_delete or annotations_to_create:
+            ttm_annotations.update(original_annotations)
+            for annotation_key in annotations_to_create:
+                self.task_annotate(
+                    original_task,
+                    ttm_annotations[annotation_key]
+                )
+            for annotation_key in annotations_to_delete:
+                self.task_denotate(
+                    original_task,
+                    ttm_annotations[annotation_key]
+                )
 
-        return self.get_task(uuid=original_task['uuid'])
+        return self.get_task(uuid=task_uuid)
 
     def task_delete(self, **kw):
         """ Marks a task as deleted.  """