Jon Herron 7c219fd731 Squashed 'SpiffWorkflow/' content from commit 63db3e4
git-subtree-dir: SpiffWorkflow
git-subtree-split: 63db3e45947ec66b8d0efc2c74064004f8ff482c
2022-10-12 10:19:53 -04:00

65 lines
2.3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2007 Samuel Abels
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301 USA
from ..exceptions import WorkflowException
from .base import TaskSpec
class StartTask(TaskSpec):
"""
This class implements the task the is placed at the beginning
of each workflow. The task has no inputs and at least one output.
If more than one output is connected, the task does an implicit
parallel split.
"""
def __init__(self, wf_spec, name='Start', **kwargs):
"""
Constructor. The name of this task is *always* 'Start'.
:type wf_spec: WorkflowSpec
:param wf_spec: A reference to the workflow specification.
:type kwargs: dict
:param kwargs: See :class:`SpiffWorkflow.specs.TaskSpec`.
"""
TaskSpec.__init__(self, wf_spec, name, **kwargs)
def _connect_notify(self, task_spec):
"""
Called by the previous task to let us know that it exists.
"""
raise WorkflowException(self, 'StartTask can not have any inputs.')
def test(self):
"""
Checks whether all required attributes are set. Throws an exception
if an error was detected.
"""
if len(self.inputs) != 0:
raise WorkflowException(self, 'StartTask with an input.')
elif len(self.outputs) < 1:
raise WorkflowException(self, 'No output task connected.')
def serialize(self, serializer):
return serializer.serialize_start_task(self)
@classmethod
def deserialize(cls, serializer, wf_spec, s_state):
return serializer.deserialize_start_task(wf_spec, s_state)