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