tasklib/backends.py

   1 import abc
   2 import json
   3 import os
   4 import re
   5 import subprocess
   6
   7 from tasklib.task import TaskFilter
   8
   9 VERSION_2_1_0 = six.u('2.1.0')
  10 VERSION_2_2_0 = six.u('2.2.0')
  11 VERSION_2_3_0 = six.u('2.3.0')
  12 VERSION_2_4_0 = six.u('2.4.0')
  13 VERSION_2_4_1 = six.u('2.4.1')
  14 VERSION_2_4_2 = six.u('2.4.2')
  15 VERSION_2_4_3 = six.u('2.4.3')
  16 VERSION_2_4_4 = six.u('2.4.4')
  17 VERSION_2_4_5 = six.u('2.4.5')
  18
  19
  20 class Backend(object):
  21
  22     filter_class = TaskFilter
  23
  24     @abc.abstractmethod
  25     def filter_tasks(self, filter_obj):
  26         """Returns a list of Task objects matching the given filter"""
  27         pass
  28
  29     @abc.abstractmethod
  30     def save_task(self, task):
  31         pass
  32
  33     @abc.abstractmethod
  34     def delete_task(self, task):
  35         pass
  36
  37     @abc.abstractmethod
  38     def start_task(self, task):
  39         pass
  40
  41     @abc.abstractmethod
  42     def stop_task(self, task):
  43         pass
  44
  45     @abc.abstractmethod
  46     def complete_task(self, task):
  47         pass
  48
  49     @abc.abstractmethod
  50     def refresh_task(self, task, after_save=False):
  51         """
  52         Refreshes the given task. Returns new data dict with serialized
  53         attributes.
  54         """
  55         pass
  56
  57     @abc.abstractmethod
  58     def annotate_task(self, task, annotation):
  59         pass
  60
  61     @abc.abstractmethod
  62     def denotate_task(self, task, annotation):
  63         pass
  64
  65     @abc.abstractmethod
  66     def sync(self):
  67         """Syncs the backend database with the taskd server"""
  68         pass
  69
  70
  71 class TaskWarriorException(Exception):
  72     pass
  73
  74
  75 class TaskWarrior(object):
  76     def __init__(self, data_location=None, create=True, taskrc_location='~/.taskrc'):
  77         self.taskrc_location = os.path.expanduser(taskrc_location)
  78
  79         # If taskrc does not exist, pass / to use defaults and avoid creating
  80         # dummy .taskrc file by TaskWarrior
  81         if not os.path.exists(self.taskrc_location):
  82             self.taskrc_location = '/'
  83
  84         self.version = self._get_version()
  85         self.config = {
  86             'confirmation': 'no',
  87             'dependency.confirmation': 'no',  # See TW-1483 or taskrc man page
  88             'recurrence.confirmation': 'no',  # Necessary for modifying R tasks
  89
  90             # Defaults to on since 2.4.5, we expect off during parsing
  91             'json.array': 'off',
  92
  93             # 2.4.3 onwards supports 0 as infite bulk, otherwise set just
  94             # arbitrary big number which is likely to be large enough
  95             'bulk': 0 if self.version >= VERSION_2_4_3 else 100000,
  96         }
  97
  98         # Set data.location override if passed via kwarg
  99         if data_location is not None:
 100             data_location = os.path.expanduser(data_location)
 101             if create and not os.path.exists(data_location):
 102                 os.makedirs(data_location)
 103             self.config['data.location'] = data_location
 104
 105         self.tasks = TaskQuerySet(self)
 106
 107     def _get_command_args(self, args, config_override=None):
 108         command_args = ['task', 'rc:{0}'.format(self.taskrc_location)]
 109         config = self.config.copy()
 110         config.update(config_override or dict())
 111         for item in config.items():
 112             command_args.append('rc.{0}={1}'.format(*item))
 113         command_args.extend(map(six.text_type, args))
 114         return command_args
 115
 116     def _get_version(self):
 117         p = subprocess.Popen(
 118                 ['task', '--version'],
 119                 stdout=subprocess.PIPE,
 120                 stderr=subprocess.PIPE)
 121         stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
 122         return stdout.strip('\n')
 123
 124     def get_config(self):
 125         raw_output = self.execute_command(
 126                 ['show'],
 127                 config_override={'verbose': 'nothing'}
 128             )
 129
 130         config = dict()
 131         config_regex = re.compile(r'^(?P<key>[^\s]+)\s+(?P<value>[^\s].+$)')
 132
 133         for line in raw_output:
 134             match = config_regex.match(line)
 135             if match:
 136                 config[match.group('key')] = match.group('value').strip()
 137
 138         return config
 139
 140     def execute_command(self, args, config_override=None, allow_failure=True,
 141                         return_all=False):
 142         command_args = self._get_command_args(
 143             args, config_override=config_override)
 144         logger.debug(' '.join(command_args))
 145         p = subprocess.Popen(command_args, stdout=subprocess.PIPE,
 146                              stderr=subprocess.PIPE)
 147         stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
 148         if p.returncode and allow_failure:
 149             if stderr.strip():
 150                 error_msg = stderr.strip()
 151             else:
 152                 error_msg = stdout.strip()
 153             raise TaskWarriorException(error_msg)
 154
 155         # Return all whole triplet only if explicitly asked for
 156         if not return_all:
 157             return stdout.rstrip().split('\n')
 158         else:
 159             return (stdout.rstrip().split('\n'),
 160                     stderr.rstrip().split('\n'),
 161                     p.returncode)
 162
 163     def enforce_recurrence(self):
 164         # Run arbitrary report command which will trigger generation
 165         # of recurrent tasks.
 166
 167         # Only necessary for TW up to 2.4.1, fixed in 2.4.2.
 168         if self.version < VERSION_2_4_2:
 169             self.execute_command(['next'], allow_failure=False)
 170
 171     def merge_with(self, path, push=False):
 172         path = path.rstrip('/') + '/'
 173         self.execute_command(['merge', path], config_override={
 174             'merge.autopush': 'yes' if push else 'no',
 175         })
 176
 177     def undo(self):
 178         self.execute_command(['undo'])
 179
 180     # Backend interface implementation
 181
 182     def filter_tasks(self, filter_obj):
 183         self.enforce_recurrence()
 184         args = ['export', '--'] + filter_obj.get_filter_params()
 185         tasks = []
 186         for line in self.execute_command(args):
 187             if line:
 188                 data = line.strip(',')
 189                 try:
 190                     filtered_task = Task(self)
 191                     filtered_task._load_data(json.loads(data))
 192                     tasks.append(filtered_task)
 193                 except ValueError:
 194                     raise TaskWarriorException('Invalid JSON: %s' % data)
 195         return tasks
 196
 197     def save_task(self, task):
 198         """Save a task into TaskWarrior database using add/modify call"""
 199
 200         args = [task['uuid'], 'modify'] if task.saved else ['add']
 201         args.extend(task._get_modified_fields_as_args())
 202         output = self.execute_command(args)
 203
 204         # Parse out the new ID, if the task is being added for the first time
 205         if not task.saved:
 206             id_lines = [l for l in output if l.startswith('Created task ')]
 207
 208             # Complain loudly if it seems that more tasks were created
 209             # Should not happen
 210             if len(id_lines) != 1 or len(id_lines[0].split(' ')) != 3:
 211                 raise TaskWarriorException("Unexpected output when creating "
 212                                            "task: %s" % '\n'.join(id_lines))
 213
 214             # Circumvent the ID storage, since ID is considered read-only
 215             identifier = id_lines[0].split(' ')[2].rstrip('.')
 216
 217             # Identifier can be either ID or UUID for completed tasks
 218             try:
 219                 task._data['id'] = int(identifier)
 220             except ValueError:
 221                 task._data['uuid'] = identifier
 222
 223         # Refreshing is very important here, as not only modification time
 224         # is updated, but arbitrary attribute may have changed due hooks
 225         # altering the data before saving
 226         task.refresh(after_save=True)
 227
 228     def delete_task(self, task):
 229         self.execute_command([task['uuid'], 'delete'])
 230
 231     def start_task(self, task):
 232         self.execute_command([task['uuid'], 'start'])
 233
 234     def stop_task(self, task):
 235         self.execute_command([task['uuid'], 'stop'])
 236
 237     def complete_task(self, task):
 238         # Older versions of TW do not stop active task at completion
 239         if self.version < VERSION_2_4_0 and task.active:
 240             task.stop()
 241
 242         self.execute_command([task['uuid'], 'done'])
 243
 244     def refresh_task(self, task, after_save=False):
 245         # We need to use ID as backup for uuid here for the refreshes
 246         # of newly saved tasks. Any other place in the code is fine
 247         # with using UUID only.
 248         args = [task['uuid'] or task['id'], 'export']
 249         output = self.execute_command(args)
 250
 251         def valid(output):
 252             return len(output) == 1 and output[0].startswith('{')
 253
 254         # For older TW versions attempt to uniquely locate the task
 255         # using the data we have if it has been just saved.
 256         # This can happen when adding a completed task on older TW versions.
 257         if (not valid(output) and self.version < VERSION_2_4_5
 258                 and after_save):
 259
 260             # Make a copy, removing ID and UUID. It's most likely invalid
 261             # (ID 0) if it failed to match a unique task.
 262             data = copy.deepcopy(task._data)
 263             data.pop('id', None)
 264             data.pop('uuid', None)
 265
 266             taskfilter = self.filter_class(self)
 267             for key, value in data.items():
 268                 taskfilter.add_filter_param(key, value)
 269
 270             output = self.execute_command(['export', '--'] +
 271                 taskfilter.get_filter_params())
 272
 273         # If more than 1 task has been matched still, raise an exception
 274         if not valid(output):
 275             raise TaskWarriorException(
 276                 "Unique identifiers {0} with description: {1} matches "
 277                 "multiple tasks: {2}".format(
 278                 task['uuid'] or task['id'], task['description'], output)
 279             )
 280
 281         return json.loads(output[0])
 282
 283     def sync(self):
 284         self.execute_command(['sync'])