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