Update README to reflect new filtering API

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

diff --git a/tasklib/task.py b/tasklib/task.py
index a220264f79b0203d773902628afdb3fe9ce893d2..4681418448b1ca18b77a5bf5b69f2f9850ebf9f4 100644 (file)
--- a/tasklib/task.py
+++ b/tasklib/task.py
@@ -1,3 +1,5 @@
+import copy
+import datetime

 import json
 import os
 import subprocess
 import json
 import os
 import subprocess


@@ -5,6 +7,10 @@ import tempfile
 import uuid
 
 
 import uuid
 
 

+DATE_FORMAT = '%Y%m%dT%H%M%SZ'
+
+REPR_OUTPUT_SIZE = 10
+

 PENDING = 'pending'
 
 
 PENDING = 'pending'
 
 


@@ -14,12 +20,15 @@ class TaskWarriorException(Exception):
 
 class Task(object):
 
 
 class Task(object):
 

+    class DoesNotExist(Exception):
+        pass
+

     def __init__(self, warrior, data={}):
         self.warrior = warrior
         self._data = data
 
     def __getitem__(self, key):
     def __init__(self, warrior, data={}):
         self.warrior = warrior
         self._data = data
 
     def __getitem__(self, key):

-        return self._data.get(key)
+        return self._get_field(key)

 
     def __setitem__(self, key, val):
         self._data[key] = val
 
     def __setitem__(self, key, val):
         self._data[key] = val


@@ -27,6 +36,35 @@ class Task(object):
     def __unicode__(self):
         return self._data.get('description')
 
     def __unicode__(self):
         return self._data.get('description')
 

+    def _get_field(self, key):
+        hydrate_func = getattr(self, 'deserialize_{0}'.format(key), lambda x:x)
+        return hydrate_func(self._data.get(key))
+
+    def _set_field(self, key, value):
+        dehydrate_func = getattr(self, 'serialize_{0}'.format(key), lambda x:x)
+        self._data[key] = dehydrate_func(value)
+
+    def serialize_due(self, date):
+        return date.strftime(DATE_FORMAT)
+
+    def deserialize_due(self, date_str):
+        if not date_str:
+            return None
+        return datetime.datetime.strptime(date_str, DATE_FORMAT)
+
+    def serialize_annotations(self, annotations):
+        ann_list = list(annotations)
+        for ann in ann_list:
+            ann['entry'] = ann['entry'].strftime(DATE_FORMAT)
+        return ann_list
+
+    def deserialize_annotations(self, annotations):
+        ann_list = list(annotations)
+        for ann in ann_list:
+            ann['entry'] = datetime.datetime.strptime(
+                ann['entry'], DATE_FORMAT)
+        return ann_list
+

     def regenerate_uuid(self):
         self['uuid'] = str(uuid.uuid4())
 
     def regenerate_uuid(self):
         self['uuid'] = str(uuid.uuid4())
 


@@ -46,6 +84,137 @@ class Task(object):
     __repr__ = __unicode__
 
 
     __repr__ = __unicode__
 
 

+class TaskFilter(object):
+    """
+    A set of parameters to filter the task list with.
+    """
+
+    def __init__(self, filter_params=[]):
+        self.filter_params = filter_params
+
+    def add_filter(self, filter_str):
+        self.filter_params.append(filter_str)
+
+    def add_filter_param(self, key, value):
+        key = key.replace('__', '.')
+        self.filter_params.append('{0}:{1}'.format(key, value))
+
+    def get_filter_params(self):
+        return [f for f in self.filter_params if f]
+
+    def clone(self):
+        c = self.__class__()
+        c.filter_params = list(self.filter_params)
+        return c
+
+
+class TaskQuerySet(object):
+    """
+    Represents a lazy lookup for a task objects.
+    """
+
+    def __init__(self, warrior=None, filter_obj=None):
+        self.warrior = warrior
+        self._result_cache = None
+        self.filter_obj = filter_obj or TaskFilter()
+
+    def __deepcopy__(self, memo):
+        """
+        Deep copy of a QuerySet doesn't populate the cache
+        """
+        obj = self.__class__()
+        for k,v in self.__dict__.items():
+            if k in ('_iter','_result_cache'):
+                obj.__dict__[k] = None
+            else:
+                obj.__dict__[k] = copy.deepcopy(v, memo)
+        return obj
+
+    def __repr__(self):
+        data = list(self[:REPR_OUTPUT_SIZE + 1])
+        if len(data) > REPR_OUTPUT_SIZE:
+            data[-1] = "...(remaining elements truncated)..."
+        return repr(data)
+
+    def __len__(self):
+        if self._result_cache is None:
+            self._result_cache = list(self)
+        return len(self._result_cache)
+
+    def __iter__(self):
+        if self._result_cache is None:
+            self._result_cache = self._execute()
+        return iter(self._result_cache)
+
+    def __getitem__(self, k):
+        if self._result_cache is None:
+            self._result_cache = list(self)
+        return self._result_cache.__getitem__(k)
+
+    def __bool__(self):
+        if self._result_cache is not None:
+            return bool(self._result_cache)
+        try:
+            next(iter(self))
+        except StopIteration:
+            return False
+        return True
+
+    def __nonzero__(self):
+        return type(self).__bool__(self)
+
+    def _clone(self, klass=None, **kwargs):
+        if klass is None:
+            klass = self.__class__
+        filter_obj = self.filter_obj.clone()
+        c = klass(warrior=self.warrior, filter_obj=filter_obj)
+        c.__dict__.update(kwargs)
+        return c
+
+    def _execute(self):
+        """
+        Fetch the tasks which match the current filters.
+        """
+        return self.warrior.filter_tasks(self.filter_obj)
+
+    def all(self):
+        """
+        Returns a new TaskQuerySet that is a copy of the current one.
+        """
+        return self._clone()
+
+    def pending(self):
+        return self.filter(status=PENDING)
+
+    def filter(self, *args, **kwargs):
+        """
+        Returns a new TaskQuerySet with the given filters added.
+        """
+        clone = self._clone()
+        for f in args:
+            clone.filter_obj.add_filter(f)
+        for key, value in kwargs.items():
+            clone.filter_obj.add_filter_param(key, value)
+        return clone
+
+    def get(self, **kwargs):
+        """
+        Performs the query and returns a single object matching the given
+        keyword arguments.
+        """
+        clone = self.filter(**kwargs)
+        num = len(clone)
+        if num == 1:
+            return clone._result_cache[0]
+        if not num:
+            raise Task.DoesNotExist(
+                'Task matching query does not exist. '
+                'Lookup parameters were {0}'.format(kwargs))
+        raise ValueError(
+            'get() returned more than one Task -- it returned {0}! '
+            'Lookup parameters were {1}'.format(num, kwargs))
+
+

 class TaskWarrior(object):
     DEFAULT_FILTERS = {
         'status': 'pending',
 class TaskWarrior(object):
     DEFAULT_FILTERS = {
         'status': 'pending',


@@ -57,59 +226,48 @@ class TaskWarrior(object):
         self.config = {
             'data.location': os.path.expanduser(data_location),
         }
         self.config = {
             'data.location': os.path.expanduser(data_location),
         }

+        self.tasks = TaskQuerySet(self)

 
 

-    def _generate_command(self, command):
-        args = ['task', 'rc:/']
+    def _get_command_args(self, args):
+        command_args = ['task', 'rc:/']

         for item in self.config.items():
         for item in self.config.items():

-            args.append('rc.{0}={1}'.format(*item))
-        args.append(command)
-        return ' '.join(args)
+            command_args.append('rc.{0}={1}'.format(*item))
+        command_args.extend(args)
+        return command_args

 
 

-    def _execute(self, command):
-        p = subprocess.Popen(self._generate_command(command), shell=True,
+    def _execute_command(self, args):
+        p = subprocess.Popen(self._get_command_args(args),

                              stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         stdout, stderr = p.communicate()
         if p.returncode:
             raise TaskWarriorException(stderr.strip())
         return stdout.strip().split('\n')
 
                              stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         stdout, stderr = p.communicate()
         if p.returncode:
             raise TaskWarriorException(stderr.strip())
         return stdout.strip().split('\n')
 

-    def _format_filter_kwarg(self, kwarg):
-        key, val = kwarg[0], kwarg[1]
-        if key in ['tag', 'tags']:
-            key = 'tags.equal'
-        key = key.replace('__', '.')
-        return '{0}:{1}'.format(key, val)
-
-    def get_tasks(self, **filter_kwargs):
-        filters = dict(self.DEFAULT_FILTERS)
-        filters.update(filter_kwargs)
-        filter_commands = ' '.join(map(self._format_filter_kwarg,
-                                       filters.items()))
-        command = '{0} export'.format(filter_commands)
+    def filter_tasks(self, filter_obj):
+        args = ['export', '--'] + filter_obj.get_filter_params()

         tasks = []
         tasks = []

-        for line in self._execute(command):
+        for line in self._execute_command(args):

             if line:
                 tasks.append(Task(self, json.loads(line.strip(','))))
         return tasks
 
             if line:
                 tasks.append(Task(self, json.loads(line.strip(','))))
         return tasks
 

-    def get_task(self, task_id):
-        command = '{0} export'.format(task_id)
-        return Task(self, json.loads(self._execute(command)[0]))
-

     def add_task(self, description, project=None):
         args = ['add', description]
         if project is not None:
             args.append('project:{0}'.format(project))
     def add_task(self, description, project=None):
         args = ['add', description]
         if project is not None:
             args.append('project:{0}'.format(project))

-        self._execute(' '.join(args))
+        self._execute_command(args)

 
     def delete_task(self, task_id):
 
     def delete_task(self, task_id):

-        self._execute('{0} rc.confirmation:no delete'.format(task_id))
+        args = [task_id, 'rc.confirmation:no', 'delete']
+        self._execute_command(args)

 
     def complete_task(self, task_id):
 
     def complete_task(self, task_id):

-        self._execute('{0} done'.format(task_id))
+        args = [task_id, 'done']
+        self._execute_command(args)

 
     def import_tasks(self, tasks):
         fd, path = tempfile.mkstemp()
         with open(path, 'w') as f:
             f.write(json.dumps(tasks))
 
     def import_tasks(self, tasks):
         fd, path = tempfile.mkstemp()
         with open(path, 'w') as f:
             f.write(json.dumps(tasks))

-        self._execute('import {0}'.format(path))
+        args = ['import', path]
+        self._execute_command(args)