tasklib/backends.py

   1 import abc
   2 import os
   3 import re
   4 import subprocess
   5
   6
   7 VERSION_2_1_0 = six.u('2.1.0')
   8 VERSION_2_2_0 = six.u('2.2.0')
   9 VERSION_2_3_0 = six.u('2.3.0')
  10 VERSION_2_4_0 = six.u('2.4.0')
  11 VERSION_2_4_1 = six.u('2.4.1')
  12 VERSION_2_4_2 = six.u('2.4.2')
  13 VERSION_2_4_3 = six.u('2.4.3')
  14 VERSION_2_4_4 = six.u('2.4.4')
  15 VERSION_2_4_5 = six.u('2.4.5')
  16
  17
  18 class Backend(object):
  19
  20     @abc.abstractmethod
  21     def filter_tasks(self, filter_obj):
  22         """Returns a list of Task objects matching the given filter"""
  23         pass
  24
  25     @abc.abstractmethod
  26     def save_task(self, task):
  27         pass
  28
  29     @abc.abstractmethod
  30     def delete_task(self, task):
  31         pass
  32
  33     @abc.abstractmethod
  34     def start_task(self, task):
  35         pass
  36
  37     @abc.abstractmethod
  38     def stop_task(self, task):
  39         pass
  40
  41     @abc.abstractmethod
  42     def complete_task(self, task):
  43         pass
  44
  45     @abc.abstractmethod
  46     def refresh_task(self, task):
  47         """
  48         Refreshes the given task. Returns new data dict with serialized
  49         attributes.
  50         """
  51         pass
  52
  53     @abc.abstractmethod
  54     def sync(self):
  55         """Syncs the backend database with the taskd server"""
  56         pass
  57
  58
  59 class TaskWarriorException(Exception):
  60     pass
  61
  62
  63 class TaskWarrior(object):
  64     def __init__(self, data_location=None, create=True, taskrc_location='~/.taskrc'):
  65         self.taskrc_location = os.path.expanduser(taskrc_location)
  66
  67         # If taskrc does not exist, pass / to use defaults and avoid creating
  68         # dummy .taskrc file by TaskWarrior
  69         if not os.path.exists(self.taskrc_location):
  70             self.taskrc_location = '/'
  71
  72         self.version = self._get_version()
  73         self.config = {
  74             'confirmation': 'no',
  75             'dependency.confirmation': 'no',  # See TW-1483 or taskrc man page
  76             'recurrence.confirmation': 'no',  # Necessary for modifying R tasks
  77
  78             # Defaults to on since 2.4.5, we expect off during parsing
  79             'json.array': 'off',
  80
  81             # 2.4.3 onwards supports 0 as infite bulk, otherwise set just
  82             # arbitrary big number which is likely to be large enough
  83             'bulk': 0 if self.version >= VERSION_2_4_3 else 100000,
  84         }
  85
  86         # Set data.location override if passed via kwarg
  87         if data_location is not None:
  88             data_location = os.path.expanduser(data_location)
  89             if create and not os.path.exists(data_location):
  90                 os.makedirs(data_location)
  91             self.config['data.location'] = data_location
  92
  93         self.tasks = TaskQuerySet(self)
  94
  95     def _get_command_args(self, args, config_override=None):
  96         command_args = ['task', 'rc:{0}'.format(self.taskrc_location)]
  97         config = self.config.copy()
  98         config.update(config_override or dict())
  99         for item in config.items():
 100             command_args.append('rc.{0}={1}'.format(*item))
 101         command_args.extend(map(six.text_type, args))
 102         return command_args
 103
 104     def _get_version(self):
 105         p = subprocess.Popen(
 106                 ['task', '--version'],
 107                 stdout=subprocess.PIPE,
 108                 stderr=subprocess.PIPE)
 109         stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
 110         return stdout.strip('\n')
 111
 112     def get_config(self):
 113         raw_output = self.execute_command(
 114                 ['show'],
 115                 config_override={'verbose': 'nothing'}
 116             )
 117
 118         config = dict()
 119         config_regex = re.compile(r'^(?P<key>[^\s]+)\s+(?P<value>[^\s].+$)')
 120
 121         for line in raw_output:
 122             match = config_regex.match(line)
 123             if match:
 124                 config[match.group('key')] = match.group('value').strip()
 125
 126         return config
 127
 128     def execute_command(self, args, config_override=None, allow_failure=True,
 129                         return_all=False):
 130         command_args = self._get_command_args(
 131             args, config_override=config_override)
 132         logger.debug(' '.join(command_args))
 133         p = subprocess.Popen(command_args, stdout=subprocess.PIPE,
 134                              stderr=subprocess.PIPE)
 135         stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
 136         if p.returncode and allow_failure:
 137             if stderr.strip():
 138                 error_msg = stderr.strip()
 139             else:
 140                 error_msg = stdout.strip()
 141             raise TaskWarriorException(error_msg)
 142
 143         # Return all whole triplet only if explicitly asked for
 144         if not return_all:
 145             return stdout.rstrip().split('\n')
 146         else:
 147             return (stdout.rstrip().split('\n'),
 148                     stderr.rstrip().split('\n'),
 149                     p.returncode)
 150
 151     def enforce_recurrence(self):
 152         # Run arbitrary report command which will trigger generation
 153         # of recurrent tasks.
 154
 155         # Only necessary for TW up to 2.4.1, fixed in 2.4.2.
 156         if self.version < VERSION_2_4_2:
 157             self.execute_command(['next'], allow_failure=False)
 158
 159     def merge_with(self, path, push=False):
 160         path = path.rstrip('/') + '/'
 161         self.execute_command(['merge', path], config_override={
 162             'merge.autopush': 'yes' if push else 'no',
 163         })
 164
 165     def undo(self):
 166         self.execute_command(['undo'])
 167
 168     # Backend interface implementation
 169
 170     def filter_tasks(self, filter_obj):
 171         self.enforce_recurrence()
 172         args = ['export', '--'] + filter_obj.get_filter_params()
 173         tasks = []
 174         for line in self.execute_command(args):
 175             if line:
 176                 data = line.strip(',')
 177                 try:
 178                     filtered_task = Task(self)
 179                     filtered_task._load_data(json.loads(data))
 180                     tasks.append(filtered_task)
 181                 except ValueError:
 182                     raise TaskWarriorException('Invalid JSON: %s' % data)
 183         return tasks
 184
 185     def save_task(self, task):
 186         """Save a task into TaskWarrior database using add/modify call"""
 187
 188         args = [task['uuid'], 'modify'] if task.saved else ['add']
 189         args.extend(task._get_modified_fields_as_args())
 190         output = self.execute_command(args)
 191
 192         # Parse out the new ID, if the task is being added for the first time
 193         if not task.saved:
 194             id_lines = [l for l in output if l.startswith('Created task ')]
 195
 196             # Complain loudly if it seems that more tasks were created
 197             # Should not happen
 198             if len(id_lines) != 1 or len(id_lines[0].split(' ')) != 3:
 199                 raise TaskWarriorException("Unexpected output when creating "
 200                                            "task: %s" % '\n'.join(id_lines))
 201
 202             # Circumvent the ID storage, since ID is considered read-only
 203             identifier = id_lines[0].split(' ')[2].rstrip('.')
 204
 205             # Identifier can be either ID or UUID for completed tasks
 206             try:
 207                 task._data['id'] = int(identifier)
 208             except ValueError:
 209                 task._data['uuid'] = identifier
 210
 211         # Refreshing is very important here, as not only modification time
 212         # is updated, but arbitrary attribute may have changed due hooks
 213         # altering the data before saving
 214         task.refresh(after_save=True)
 215
 216     def delete_task(self, task):
 217         self.execute_command([task['uuid'], 'delete'])
 218
 219     def start_task(self, task):
 220         self.execute_command([task['uuid'], 'start'])
 221
 222     def stop_task(self, task):
 223         self.execute_command([task['uuid'], 'stop'])
 224
 225     def complete_task(self, task):
 226         # Older versions of TW do not stop active task at completion
 227         if self.version < VERSION_2_4_0 and task.active:
 228             task.stop()
 229
 230         self.execute_command([task['uuid'], 'done'])
 231