def refuse(self, caused_by):
"""
:param caused_by: upon which node, the task flow is refused
"""
self.status = constants.WORK_FLOW_REFUSED
do_commit(self)
self._refuse_tree(self.root_node, caused_by)
def refuse(self):
"""
refuse the node, and the whole work flow
:raise yawf.exceptions.WorkFlowRefused: if work flow already refused
"""
if self.work_flow.status == yawf.constants.WORK_FLOW_REFUSED:
raise yawf.exceptions.WorkFlowRefused()
self.approved = False
self.handle_time = datetime.now()
do_commit(self)
self.work_flow.refuse(self)
def approve(self):
"""
approve the node, and retry the whole work flow to test if it is done
:raise yawf.exceptions.NodeAlreadyApproved: if node already approved
"""
if self.approved:
raise yawf.exceptions.NodeAlreadyApproved()
self.approved = True
self.handle_time = datetime.now()
do_commit(self)
self.on_approved()
self.work_flow.retry(self)
def retry(self, last_operated_node):
"""
test if all the nodes are approved, if they are, execute the nodes from
LEAF to ROOT
:raise: WorkFlowRefused when the node flow has been refused
:raise: WorkFlowDelayed when there exists node that hasn't been
approved
"""
if self.status == constants.WORK_FLOW_REFUSED:
raise WorkFlowRefused()
# then we test if all the (indirect) depenecies of ROOT are met
unmet_node = self._find_next_unmet_node(self.root_node)
if unmet_node:
last_operated_node.on_delayed(unmet_node)
self.current_node = unmet_node
do_commit(self)
raise WorkFlowDelayed(unmet_node,
"node %s is not met" % unicode(unmet_node))
self.status = constants.WORK_FLOW_APPROVED
do_commit(self)
# execute all the nodes
try:
self.root_node.execute()
self.failed = False
self.status = constants.WORK_FLOW_EXECUTED
do_commit(self)
except:
self.failed = True
do_commit(self)
raise
def dependencies(self):
ret = []
from yawf.models import WorkFlow
for policy, node_kwargs in self.policy.dependencies:
try:
node = self.query.filter(
yawf.WorkFlowEngine.instance.node_model.work_flow_id ==
self.work_flow_id).filter(
self.__class__.policy_name == policy).one()
except NoResultFound:
node_kwargs.update(policy_name=policy)
node = self.__class__(work_flow=self.work_flow, **node_kwargs)
do_commit(node)
ret.append(node)
return ret
def node_view():
class _Form(Form):
destination = TextField('destination', validators=[DataRequired()])
contact = TextField('contact', validators=[DataRequired()])
form = _Form()
if form.validate_on_submit():
work_flow = yawf.new_work_flow(
'travel application', lambda work_flow: models.Node(
name='Submit Travel Application',
policy_name="Travel",
work_flow=work_flow,
handler_group=models.Group.query.filter(models.Group.name ==
'Customers').one()),
lambda work_flow: do_commit(
models.Application(username=current_user.username,
destination=form.destination.data,
contact=form.contact.data,
work_flow=work_flow)).id)
try:
work_flow.start()
except yawf.exceptions.WorkFlowDelayed:
flash('You have just submitted an travel application')
return redirect(url_for('node_list_view'))
return render_template('/request.html', form=form)
def execute(self):
"""
execute the policy, all the dependent policy will be executed at first
"""
for node in self.node.dependencies:
node.execute()
if not self.work_flow.status == constants.WORK_FLOW_EXECUTED or self.node.failed:
try:
self()
self.node.failed = False
do_commit(self.node)
self.after_executed()
except:
self.node.failed = True
do_commit(self.node)
raise
def new_work_flow(tag,
node_creator,
tag_creator=None,
annotation=None,
token=None):
"""
create a work flow
:param tag: tag of the work flow
:param node_creator: a function to create root node, its argument is
"work_flow"
:param tag_creator: a function to create tag, its argument is "work_flow"
:param annotation: annotation of the work flow
:param token: token of the work flow
"""
work_flow = do_commit(
yawf.models.WorkFlow(tag=tag, annotation=annotation, token=token))
work_flow.root_node = do_commit(node_creator(work_flow))
work_flow.root_node.tag = tag_creator and tag_creator(work_flow)
return do_commit(work_flow)
def execute(self):
"""
execute the work flow
you must guarantee each work is a transaction
:raise WorkFlowRefused: if task flow is refused
:raise WorkFlowProcessing: if task flow is processing
:raise Exception: any exceptions raised when executing tasks
"""
if self.status == constants.WORK_FLOW_REFUSED:
raise WorkFlowRefused()
elif self.status == constants.WORK_FLOW_PROCESSING:
raise WorkFlowProcessing()
try:
self.root_node.execute()
self.failed = False
self.status == constants.WORK_FLOW_EXECUTED
do_commit(self)
except:
self.failed = True
do_commit(self)
raise
def bind(self, token):
self.token = token
do_commit(self)
#! /usr/bin/env python import types from basemain import app from database import sa_db, init_db from models import Group, User from yawf.utils import do_commit sa_db.drop_all() init_db() customers = do_commit(Group(name='Customers')) clerks = do_commit(Group(name='Clerks')) do_commit(User(username='******', group=customers)) do_commit(User(username='******', group=clerks))