Implement bottom-up recursion through tree

eos/base/election.py

@@ -36,6 +36,12 @@ class Voter(EmbeddedObject):
 
 class Question(EmbeddedObject):
 	prompt = StringField()
+	
+	def compute_result(self):
+		...
+
+class Result(EmbeddedObject):
+	pass
 
 class ApprovalQuestion(Question):
 	choices = ListField(StringField())
@@ -43,9 +49,13 @@ class ApprovalQuestion(Question):
 class ApprovalAnswer(Answer):
 	choices = ListField(IntField())
 
+class ApprovalResult(Result):
+	choices = ListField(IntField())
+
 class Election(TopLevelObject):
 	_id = UUIDField()
 	workflow = EmbeddedObjectField(Workflow) # Once saved, we don't care what kind of workflow it is
 	name = StringField()
 	voters = EmbeddedObjectListField(hashed=False)
 	questions = EmbeddedObjectListField()
+	results = EmbeddedObjectListField(hashed=False)

eos/base/tests.py

@@ -25,17 +25,30 @@ class ElectionTestCase(TestCase):
 	def setUpClass(cls):
 		client.drop_database('test')
 	
+	def exit_task_assert(self, election, task, next_task):
+		self.assertEqual(election.workflow.get_task(task).status, WorkflowTask.Status.READY)
+		self.assertEqual(election.workflow.get_task(next_task).status, WorkflowTask.Status.NOT_READY)
+		election.workflow.get_task(task).exit()
+		self.assertEqual(election.workflow.get_task(task).status, WorkflowTask.Status.EXITED)
+		self.assertEqual(election.workflow.get_task(next_task).status, WorkflowTask.Status.READY)
+	
 	def test_run_election(self):
 		# Set up election
 		election = Election()
-		election.workflow = WorkflowBase(election)
+		election.workflow = WorkflowBase()
+		
+		# Check _instance
+		self.assertEqual(election.workflow._instance, (election, 'workflow'))
 		
 		self.assertEqual(election.workflow.get_task('eos.base.workflow.TaskConfigureElection').status, WorkflowTask.Status.READY)
 		
 		election.name = 'Test Election'
 		
 		for i in range(3):
-			election.voters.append(Voter())
+			voter = Voter()
+			election.voters.append(voter)
+			# Check _instance
+			self.assertEqual(voter._instance, (election.voters, None))
 		
 		question = ApprovalQuestion(prompt='President', choices=['John Smith', 'Joe Bloggs', 'John Q. Public'])
 		election.questions.append(question)
@@ -49,12 +62,7 @@ class ElectionTestCase(TestCase):
 		self.assertEqual(db[Election._name].find_one(), election.serialise())
 		
 		# Freeze election
-		self.assertEqual(election.workflow.get_task('eos.base.workflow.TaskConfigureElection').status, WorkflowTask.Status.READY)
+		self.exit_task_assert(election, 'eos.base.workflow.TaskConfigureElection', 'eos.base.workflow.TaskOpenVoting')
-		self.assertEqual(election.workflow.get_task('eos.base.workflow.TaskOpenVoting').status, WorkflowTask.Status.NOT_READY)
-		election.workflow.get_task('eos.base.workflow.TaskConfigureElection').exit()
-		self.assertEqual(election.workflow.get_task('eos.base.workflow.TaskConfigureElection').status, WorkflowTask.Status.EXITED)
-		self.assertEqual(election.workflow.get_task('eos.base.workflow.TaskOpenVoting').status, WorkflowTask.Status.READY)
-		
 		election.save()
 		
 		# Cast ballots
@@ -69,3 +77,11 @@ class ElectionTestCase(TestCase):
 			election.voters[i].ballots.append(ballot)
 		
 		election.save()
+		
+		# Close voting
+		self.exit_task_assert(election, 'eos.base.workflow.TaskOpenVoting', 'eos.base.workflow.TaskCloseVoting')
+		election.save()
+		
+		# Compute result
+		for i in range(2):
+			result = election.questions[i].compute_result()

eos/base/workflow.py

@@ -29,13 +29,13 @@ class WorkflowTask(EmbeddedObject):
 	
 	status = IntField()
 	
-	def __init__(self, workflow=None, *args, **kwargs):
+	def __init__(self, *args, **kwargs):
 		super().__init__(*args, **kwargs)
+	
+	def post_init(self):
+		super().post_init()
 		
-		self.workflow = workflow
+		self.workflow = self.recurse_parents(Workflow)
-		
-		if self.workflow is None:
-			self.workflow = self._instance
 		
 		self.status = WorkflowTask.Status.READY if self.are_dependencies_met() else WorkflowTask.Status.NOT_READY
 		
@@ -79,9 +79,8 @@ class Workflow(EmbeddedObject):
 		'abstract': True
 	}
 	
-	def __init__(self, election=None, *args, **kwargs):
+	def __init__(self, *args, **kwargs):
 		super().__init__(*args, **kwargs)
-		self.election = election if election else self._instance
 	
 	def get_tasks(self, descriptor):
 		yield from (task for task in self.tasks if task.satisfies(descriptor))
@@ -103,12 +102,16 @@ class TaskConfigureElection(WorkflowTask):
 class TaskOpenVoting(WorkflowTask):
 	depends_on = ['eos.base.workflow.TaskConfigureElection']
 
+class TaskCloseVoting(WorkflowTask):
+	depends_on = ['eos.base.workflow.TaskOpenVoting']
+
 # Concrete workflows
 # ==================
 
 class WorkflowBase(Workflow):
-	def __init__(self, election=None, *args, **kwargs):
+	def __init__(self, *args, **kwargs):
-		super().__init__(election, *args, **kwargs)
+		super().__init__(*args, **kwargs)
 		
-		self.tasks.append(TaskConfigureElection(self))
+		self.tasks.append(TaskConfigureElection())
-		self.tasks.append(TaskOpenVoting(self))
+		self.tasks.append(TaskOpenVoting())
+		self.tasks.append(TaskCloseVoting())

eos/core/objects/python.py

@@ -58,7 +58,7 @@ class EmbeddedObjectField(Field):
 
 class ListField(Field):
 	def __init__(self, element_field=None, *args, **kwargs):
-		super().__init__(default=[], *args, **kwargs)
+		super().__init__(default=EosList, *args, **kwargs)
 		self.element_field = element_field
 	
 	def serialise(self, value):
@@ -69,7 +69,7 @@ class ListField(Field):
 
 class EmbeddedObjectListField(Field):
 	def __init__(self, object_type=None, *args, **kwargs):
-		super().__init__(default=[], *args, **kwargs)
+		super().__init__(default=EosList, *args, **kwargs)
 		self.object_type = object_type
 	
 	def serialise(self, value):
@@ -102,6 +102,20 @@ class EosObjectType(type):
 class EosObject(metaclass=EosObjectType):
 	objects = {}
 	
+	def __init__(self):
+		self._instance = (None, None)
+		self._inited = False
+	
+	def post_init(self):
+		self._inited = True
+	
+	def recurse_parents(self, cls):
+		if isinstance(self, cls):
+			return self
+		if self._instance[0]:
+			return self._instance[0].recurse_parents(cls)
+		return None
+	
 	@staticmethod
 	def serialise_and_wrap(value, object_type=None):
 		if object_type:
@@ -114,6 +128,14 @@ class EosObject(metaclass=EosObjectType):
 			return object_type.deserialise(value)
 		return EosObject.objects[value['type']].deserialise(value['value'])
 
+class EosList(EosObject, list):
+	def append(self, value):
+		if isinstance(value, EosObject):
+			value._instance = (self, None)
+			if not value._inited:
+				value.post_init()
+		return super().append(value)
+
 class DocumentObjectType(EosObjectType):
 	def __new__(meta, name, bases, attrs):
 		cls = EosObjectType.__new__(meta, name, bases, attrs)
@@ -123,14 +145,35 @@ class DocumentObjectType(EosObjectType):
 		for attr in list(dir(cls)):
 			val = getattr(cls, attr)
 			if isinstance(val, Field):
+				val._instance = (cls, name)
 				fields[attr] = val
 				delattr(cls, attr)
 		cls._fields = fields
 		
+		# Make properties
+		def make_property(name, field):
+			def field_getter(self):
+				return self._field_values[name]
+			def field_setter(self, value):
+				if isinstance(value, EosObject):
+					value._instance = (self, name)
+					if not value._inited:
+						value.post_init()
+				
+				self._field_values[name] = value
+			return property(field_getter, field_setter)
+		
+		for attr, val in fields.items():
+			setattr(cls, attr, make_property(attr, val))
+		
 		return cls
 
-class DocumentObject(metaclass=DocumentObjectType):
+class DocumentObject(EosObject, metaclass=DocumentObjectType):
 	def __init__(self, *args, **kwargs):
+		super().__init__()
+		
+		self._field_values = {}
+		
 		for attr, val in self._fields.items():
 			if attr in kwargs:
 				setattr(self, attr, kwargs[attr])