def create_new_flow(self):
# don't repeat the actions from create_new_element() !
if self.title is None:
self.flow_model = FlowModel(element = self.element_model)
else:
self.flow_model = FlowModel(element = self.element_model, title = self.title)
self.flow_model.save()
class Flow(Element):
class_name = "flow"
def __init__(self, title = None, flow_id = None, element_model = None):
self.elements = []
self.element_groups = []
if (flow_id is None) and (element_model is None):
# creating a new object : first create the Element(), then create a new flow
super(Flow, self).__init__(title = title)
self.create_new_flow()
else:
# loading an existing object : first get the element_model, then load the element from DB, then load the flow from DB
if (element_model is None):
# assume flow_id is not None
# get flow_model and element_model from flow_id
flow_model = FlowModel.objects.get(pk = flow_id)
element_model = flow_model.element
else:
# we got element_model, get flow_model from it
flow_model = element_model.flowmodel
super(Flow, self).__init__(title = title, element_model = element_model)
self.load_flow_from_database(flow_model)
def create_new_flow(self):
# don't repeat the actions from create_new_element() !
if self.title is None:
self.flow_model = FlowModel(element = self.element_model)
else:
self.flow_model = FlowModel(element = self.element_model, title = self.title)
self.flow_model.save()
def load_flow_from_database(self, flow_model = None):
self.flow_model = flow_model
self.title = self.flow_model.title
for element_model in self.flow_model.elementmodel_set.all():
specific_class = get_class_for_element_type(element_model.class_name)
element = specific_class(element_model = element_model)
self.add_element(element)
element.find_and_set_group_update_grouplist(self.element_groups)
for element in self.elements:
if not(isinstance(element, Connection)):
continue
src_element_id = element.connection_model.src_element.id
dst_element_id = element.connection_model.dst_element.id
src_element = self.get_element(element_id = src_element_id)
dst_element = self.get_element(element_id = dst_element_id)
src = src_element.get_connector(element.connection_model.src_connector)
dst = dst_element.get_connector(element.connection_model.dst_connector)
element.set_src_dst(src, dst)
@classmethod
def get_all_saved_flows(cls):
return FlowModel.objects.all()
def get_id(self):
return self.element_model.id
def add_element(self, element):
element.set_flow(self)
self.elements.append(element)
if (type(element) == InputData) and not(element.title is None):
self.input_connectors.append(element.data_in)
setattr(self, element.title, element.data_in)
if (type(element) == OutputData) and not(element.title is None):
self.output_connectors.append(element.data_out)
setattr(self, element.title, element.data_out)
def get_element(self, title = None, element_id = None):
if element_id is not None:
for element in self.elements:
if element.element_model.id == element_id:
return element
if isinstance(element, Flow):
try:
return element.get_element(element_id = element_id)
except ElementNotFoundError:
pass
raise ElementNotFoundError("Could not find element with id == %d" % (element_id))
if title is not None:
for element in self.elements:
if element.title == title:
return element
raise ElementNotFoundError("Could not find element with title == %s" % (title))
raise ValueError("Atleast title or element_id should be provided")
def get_num_elements(self):
return len(self.elements)
def remove_element(self, element):
# invalidate all the output connectors of this element + everything in this flow that depends on them
for invalid_connector in element.output_connectors:
self.invalidate_chain(invalid_connector)
# Remove the element from this flow object
self.elements.remove(element)
# Remove the linked connections from this flow object
# We need to iterate over a copy of self.elements[], because items will be removed from it
for connection in self.elements[:]:
if not(isinstance(connection, Connection)):
continue
if connection.dst in element.input_connectors:
self.disconnect(connection)
continue
if connection.src in element.output_connectors:
self.disconnect(connection)
continue
# Remove the element from the database
# The database will automatically be updated to also remove the connections linked to this element
element.delete()
def connect(self, src, dst, title = None):
for element in self.elements:
if not(isinstance(element, Connection)):
continue
if (element.dst != dst):
continue
self.disconnect(element)
break
connection = Connection(title = title)
connection.set_flow(self)
connection.set_src_dst(src, dst)
self.elements.append(connection)
return connection
def disconnect(self, connection):
self.elements.remove(connection)
needs_invalidate = connection.dst.default_needs_invalidate()
if needs_invalidate:
self.invalidate_chain(connection.dst)
connection.dst.default() # need to set default *after* invalidate()
connection.delete()
def invalidate_chain(self, invalid_connector):
invalid_connector.invalidate_connector()
for element in self.elements:
if invalid_connector in element.input_connectors:
# only return connectors which were still valid and are now made invalid
new_invalid_connectors = element.invalidate_element(invalid_connector)
for new_invalid_connector in new_invalid_connectors:
self.invalidate_chain(new_invalid_connector)
# extend element.invalidate_element() in case of element == Flow()
# we need to also invalidate the internal flow, not just the output connectors
# at the end, we need to return the result of element.invalidate_element()
# which is the list of output connectors that were invalidated
def invalidate_element(self, invalid_connector):
result = super(Flow, self).invalidate_element(invalid_connector)
self.invalidate_chain(invalid_connector)
return result
def run(self, iteration = 0, debug = False):
if debug:
print
print self.title, ":: run() :: iteration", iteration
print
elements_done = 0
for element in self.elements:
if element.is_ready() and not element.is_done():
if debug:
print self.title, " execute element :", element
element.run_or_block(debug = debug)
elements_done += 1
if debug:
print
print self.title, " elements_done =", elements_done
print
if elements_done == 0:
return True
return self.run(iteration + 1, debug = debug)
def debug_state(self):
print "==== FLOW : %s ====" % self.title
super(Flow, self).debug_state()
for element in self.elements:
element.debug_state()
print "==== ===="
