backends: Make the filter_class an abstractproperty

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

diff --git a/tasklib/backends.py b/tasklib/backends.py
index 38b88b1ba042401a908f2116f4ac0cacb1189cd2..0d01470c123208ca39cb017877c94c754bb6e45c 100644 (file)
--- a/tasklib/backends.py
+++ b/tasklib/backends.py
@@ -4,7 +4,10 @@ import os
 import re
 import subprocess
 
-from tasklib.task import TaskFilter
+from tasklib.filters import TaskWarriorFilter
+from tasklib.serializing import local_zone
+
+DATE_FORMAT_CALC = '%Y-%m-%dT%H:%M:%S'
 
 VERSION_2_1_0 = six.u('2.1.0')
 VERSION_2_2_0 = six.u('2.2.0')
@@ -19,7 +22,10 @@ VERSION_2_4_5 = six.u('2.4.5')
 
 class Backend(object):
 
-    filter_class = TaskFilter
+    @abc.abstractproperty
+    def filter_class(self):
+        """Returns the TaskFilter class used by this backend"""
+        pass
 
     @abc.abstractmethod
     def filter_tasks(self, filter_obj):
@@ -67,6 +73,13 @@ class Backend(object):
         """Syncs the backend database with the taskd server"""
         pass
 
+    def convert_datetime_string(self, value):
+        """
+        Converts TW syntax datetime string to a localized datetime
+        object. This method is not mandatory.
+        """
+        raise NotImplemented
+
 
 class TaskWarriorException(Exception):
     pass
@@ -139,10 +152,10 @@ class TaskWarrior(object):
             format_default = lambda: six.u("{0}:{1}").format(field,
                                                       escaped_serialized_value)
 
-            format_func = getattr(task, 'format_{0}'.format(field),
+            format_func = getattr(self, 'format_{0}'.format(field),
                                   format_default)
 
-            args.append(format_func())
+            args.append(format_func(task))
 
         # If we're modifying saved task, simply pass on all modified fields
         if task.saved:
@@ -157,6 +170,52 @@ class TaskWarrior(object):
 
         return args
 
+    def format_depends(self, task):
+        # 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 = task._original_data.get('depends', set())
+
+        added = self['depends'] - old_dependencies
+        removed = old_dependencies - self['depends']
+
+        # Removed dependencies need to be prefixed with '-'
+        return 'depends:' + ','.join(
+                [t['uuid'] for t in added] +
+                ['-' + t['uuid'] for t in removed]
+            )
+
+    def format_description(self, task):
+        # Task version older than 2.4.0 ignores first word of the
+        # task description if description: prefix is used
+        if self.version < VERSION_2_4_0:
+            return task._data['description']
+        else:
+            return six.u("description:'{0}'").format(task._data['description'] or '')
+
+    def convert_datetime_string(self, value):
+
+        if self.version >= VERSION_2_4_0:
+            # For strings, use 'task calc' to evaluate the string to datetime
+            # available since TW 2.4.0
+            args = value.split()
+            result = self.execute_command(['calc'] + args)
+            naive = datetime.datetime.strptime(result[0], DATE_FORMAT_CALC)
+            localized = local_zone.localize(naive)
+        else:
+            raise ValueError("Provided value could not be converted to "
+                             "datetime, its type is not supported: {}"
+                             .format(type(value)))
+
+    @property
+    def filter_class(self):
+        return TaskWarriorFilter
+
+    # Public interface
 
     def get_config(self):
         raw_output = self.execute_command(