import logging
from django.contrib.contenttypes.models import ContentType
from django.db.models import CASCADE
from django.db.models.signals import post_save, post_delete
from river.core.riverobject import RiverObject
from river.core.workflowregistry import workflow_registry
from river.models import OnApprovedHook, OnTransitHook, OnCompleteHook
try:
from django.contrib.contenttypes.fields import GenericRelation
except ImportError:
from django.contrib.contenttypes.generic import GenericRelation
from river.models.state import State
from river.models.transitionapproval import TransitionApproval
from river.models.transition import Transition
from django.db import models
LOGGER = logging.getLogger(__name__)
class classproperty(object):
def __init__(self, getter):
self.getter = getter
def __get__(self, instance, owner):
return self.getter(instance) if instance else self.getter(owner)
class StateField(models.ForeignKey):
def __init__(self, *args, **kwargs):
self.field_name = None
kwargs['null'] = True
kwargs['blank'] = True
kwargs['to'] = '%s.%s' % (State._meta.app_label, State._meta.object_name)
kwargs['on_delete'] = kwargs.get('on_delete', CASCADE)
kwargs['related_name'] = "+"
super(StateField, self).__init__(*args, **kwargs)
def contribute_to_class(self, cls, name, *args, **kwargs):
@classproperty
def river(_self):
return RiverObject(_self)
self.field_name = name
self._add_to_class(cls, self.field_name + "_transition_approvals",
GenericRelation('%s.%s' % (TransitionApproval._meta.app_label, TransitionApproval._meta.object_name)))
self._add_to_class(cls, self.field_name + "_transitions", GenericRelation('%s.%s' % (Transition._meta.app_label, Transition._meta.object_name)))
if id(cls) not in workflow_registry.workflows:
self._add_to_class(cls, "river", river)
super(StateField, self).contribute_to_class(cls, name, *args, **kwargs)
if id(cls) not in workflow_registry.workflows:
post_save.connect(_on_workflow_object_saved, self.model, False, dispatch_uid='%s_%s_riverstatefield_post' % (self.model, name))
post_delete.connect(_on_workflow_object_deleted, self.model, False, dispatch_uid='%s_%s_riverstatefield_post' % (self.model, name))
workflow_registry.add(self.field_name, cls)
@staticmethod
def _add_to_class(cls, key, value, ignore_exists=False):
if ignore_exists or not hasattr(cls, key):
cls.add_to_class(key, value)
def _on_workflow_object_saved(sender, instance, created, *args, **kwargs):
for instance_workflow in instance.river.all(instance.__class__):
if created:
instance_workflow.initialize_approvals()
if not instance_workflow.get_state():
init_state = getattr(instance.__class__.river, instance_workflow.field_name).initial_state
instance_workflow.set_state(init_state)
instance.save()
def _on_workflow_object_deleted(sender, instance, *args, **kwargs):
OnApprovedHook.objects.filter(object_id=instance.pk, content_type=ContentType.objects.get_for_model(instance.__class__)).delete()
OnTransitHook.objects.filter(object_id=instance.pk, content_type=ContentType.objects.get_for_model(instance.__class__)).delete()
OnCompleteHook.objects.filter(object_id=instance.pk, content_type=ContentType.objects.get_for_model(instance.__class__)).delete()
