Task: Add support for start command

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

diff --git a/tasklib/task.py b/tasklib/task.py
index 51c97d31736dc0a9e3d6aa631f940c3e6fae2344..dc83e9706eaa875c1d13ac3350fe5c18e9677982 100644 (file)
--- a/tasklib/task.py
+++ b/tasklib/task.py
@@ -28,6 +28,37 @@ class TaskWarriorException(Exception):
     pass
 
 
+class ReadOnlyDictView(object):
+    """
+    Provides simplified read-only view upon dict object.
+    """
+
+    def __init__(self, viewed_dict):
+        self.viewed_dict = viewed_dict
+
+    def __getitem__(self, key):
+        return copy.deepcopy(self.viewed_dict.__getitem__(key))
+
+    def __contains__(self, k):
+        return self.viewed_dict.__contains__(k)
+
+    def __iter__(self):
+        for value in self.viewed_dict:
+            yield copy.deepcopy(value)
+
+    def __len__(self):
+        return len(self.viewed_dict)
+
+    def get(self, key, default=None):
+        return copy.deepcopy(self.viewed_dict.get(key, default))
+
+    def items(self):
+        return [copy.deepcopy(v) for v in self.viewed_dict.items()]
+
+    def values(self):
+        return [copy.deepcopy(v) for v in self.viewed_dict.values()]
+
+
 class SerializingObject(object):
     """
     Common ancestor for TaskResource & TaskFilter, since they both
@@ -44,6 +75,15 @@ class SerializingObject(object):
         not export empty-valued attributes) if the attribute
         is not iterable (e.g. list or set), in which case
         a empty iterable should be used.
+
+    Normalizing methods should hold the following contract:
+      - They are used to validate and normalize the user input.
+        Any attribute value that comes from the user (during Task
+        initialization, assignign values to Task attributes, or
+        filtering by user-provided values of attributes) is first
+        validated and normalized using the normalize_{key} method.
+      - If validation or normalization fails, normalizer is expected
+        to raise ValueError.
     """
 
     def _deserialize(self, key, value):
@@ -63,6 +103,10 @@ class SerializingObject(object):
         or entered as a value of Task attribute.
         """
 
+        # None value should not be converted by normalizer
+        if value is None:
+            return None
+
         normalize_func = getattr(self, 'normalize_{0}'.format(key),
                                  lambda x: x)
 
@@ -193,9 +237,16 @@ class SerializingObject(object):
             # If the value is already localized, there is no need to change
             # time zone at this point. Also None is a valid value too.
             localized = value
-        
+
         return localized
-            
+
+    def normalize_uuid(self, value):
+        # Enforce sane UUID
+        if not isinstance(value, six.string_types) or value == '':
+            raise ValueError("UUID must be a valid non-empty string, "
+                             "not: {}".format(value))
+
+        return value
 
 
 class TaskResource(SerializingObject):
@@ -334,7 +385,7 @@ class Task(TaskResource):
         pass
 
     @classmethod
-    def from_input(cls, input_file=sys.stdin, modify=None):
+    def from_input(cls, input_file=sys.stdin, modify=None, warrior=None):
         """
         Creates a Task object, directly from the stdin, by reading one line.
         If modify=True, two lines are used, first line interpreted as the
@@ -350,13 +401,18 @@ class Task(TaskResource):
         but defaults to sys.stdin.
         """
 
-        # TaskWarrior instance is set to None
-        task = cls(None)
-
         # Detect the hook type if not given directly
         name = os.path.basename(sys.argv[0])
         modify = name.startswith('on-modify') if modify is None else modify
 
+        # Create the TaskWarrior instance if none passed
+        if warrior is None:
+            hook_parent_dir = os.path.dirname(os.path.dirname(sys.argv[0]))
+            warrior = TaskWarrior(data_location=hook_parent_dir)
+
+        # TaskWarrior instance is set to None
+        task = cls(warrior)
+
         # Load the data from the input
         task._load_data(json.loads(input_file.readline().strip()))
 
@@ -384,6 +440,9 @@ class Task(TaskResource):
                           for (key, value) in six.iteritems(kwargs))
         self._original_data = copy.deepcopy(self._data)
 
+        # Provide read only access to the original data
+        self.original = ReadOnlyDictView(self._original_data)
+
     def __unicode__(self):
         return self['description']
 
@@ -475,6 +534,22 @@ class Task(TaskResource):
         # Refresh the status again, so that we have updated info stored
         self.refresh(only_fields=['status'])
 
+    def start(self):
+        if not self.saved:
+            raise Task.NotSaved("Task needs to be saved before it can be started")
+
+        # Refresh, and raise exception if task is already completed/deleted
+        self.refresh(only_fields=['status'])
+
+        if self.completed:
+            raise Task.CompletedTask("Cannot start a completed task")
+        elif self.deleted:
+            raise Task.DeletedTask("Deleted task cannot be started")
+
+        self.warrior.execute_command([self['uuid'], 'start'])
+
+        # Refresh the status again, so that we have updated info stored
+        self.refresh(only_fields=['status'])
 
     def done(self):
         if not self.saved:
@@ -786,7 +861,7 @@ class TaskWarrior(object):
         stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
         if p.returncode and allow_failure:
             if stderr.strip():
-                error_msg = stderr.strip().splitlines()[-1]
+                error_msg = stderr.strip()
             else:
                 error_msg = stdout.strip()
             raise TaskWarriorException(error_msg)