Class-based directives

examples/smtp_envelope_example.py

@@ -0,0 +1,30 @@
+import envelopes
+import hug
+
+
+@hug.directive()
+class SMTP(object):
+
+    def __init__(self, *args, **kwargs):
+        self.smtp = envelopes.SMTP(host='127.0.0.1')
+        self.envelopes_to_send = list()
+
+    def send_envelope(self, envelope):
+        self.envelopes_to_send.append(envelope)
+
+    def cleanup(self, exception=None):
+        if exception:
+            return
+        for envelope in self.envelopes_to_send:
+            self.smtp.send(envelope)
+
+
+@hug.get('/hello')
+def send_hello_email(smtp: SMTP):
+    envelope = envelopes.Envelope(
+        from_addr=(u'me@example.com', u'From me'),
+        to_addr=(u'world@example.com', u'To World'),
+        subject=u'Hello',
+        text_body=u"World!"
+    )
+    smtp.send_envelope(envelope)

examples/sqlalchemy_example.py

@@ -0,0 +1,58 @@
+import hug
+
+from sqlalchemy import create_engine, Column, Integer, String
+from sqlalchemy.ext.declarative.api import declarative_base
+from sqlalchemy.orm.session import Session
+from sqlalchemy.orm import scoped_session
+from sqlalchemy.orm import sessionmaker
+
+
+engine = create_engine("sqlite:///:memory:")
+
+session_factory = scoped_session(sessionmaker(bind=engine))
+
+
+Base = declarative_base()
+
+
+class TestModel(Base):
+    __tablename__ = 'test_model'
+    id = Column(Integer, primary_key=True)
+    name = Column(String)
+
+
+Base.metadata.create_all(bind=engine)
+
+
+@hug.directive()
+class Resource(object):
+
+    def __init__(self, *args, **kwargs):
+        self._db = session_factory()
+        self.autocommit = True
+
+    @property
+    def db(self) -> Session:
+        return self._db
+
+    def cleanup(self, exception=None):
+        if exception:
+            self.db.rollback()
+            return
+        if self.autocommit:
+            self.db.commit()
+
+
+@hug.directive()
+def return_session() -> Session:
+    return session_factory()
+
+
+@hug.get('/hello')
+def make_simple_query(resource: Resource):
+    for word in ["hello", "world", ":)"]:
+        test_model = TestModel()
+        test_model.name = word
+        resource.db.add(test_model)
+        resource.db.flush()
+    return " ".join([obj.name for obj in resource.db.query(TestModel).all()])

hug/interface.py

@@ -270,6 +270,13 @@ def _rewrite_params(self, params):
             if interface_name in params:
                 params[internal_name] = params.pop(interface_name)
 
+    @staticmethod
+    def cleanup_parameters(parameters, exception=None):
+        for parameter, directive in parameters.items():
+            if hasattr(directive, 'cleanup'):
+                directive.cleanup(exception=exception)
+
+
 class Local(Interface):
     """Defines the Interface responsible for exposing functions locally"""
     __slots__ = ('skip_directives', 'skip_validation', 'version')
@@ -325,7 +332,12 @@ def __call__(self, *args, **kwargs):
 
         if getattr(self, 'map_params', None):
             self._rewrite_params(kwargs)
-        result = self.interface(**kwargs)
+        try:
+            result = self.interface(**kwargs)
+            self.cleanup_parameters(kwargs)
+        except Exception as exception:
+            self.cleanup_parameters(kwargs, exception=exception)
+            raise exception
         if self.transform:
             result = self.transform(result)
         return self.outputs(result) if self.outputs else result
@@ -480,11 +492,15 @@ def __call__(self):
         if getattr(self, 'map_params', None):
             self._rewrite_params(pass_to_function)
 
-        if args:
-            result = self.interface(*args, **pass_to_function)
-        else:
-            result = self.interface(**pass_to_function)
-
+        try:
+            if args:
+                result = self.interface(*args, **pass_to_function)
+            else:
+                result = self.interface(**pass_to_function)
+            self.cleanup_parameters(pass_to_function)
+        except Exception as exception:
+            self.cleanup_parameters(pass_to_function, exception=exception)
+            raise exception
         return self.output(result)
 
 
@@ -559,7 +575,6 @@ def gather_parameters(self, request, response, api_version=None, **input_paramet
             arguments = (self.defaults[parameter], ) if parameter in self.defaults else ()
             input_parameters[parameter] = directive(*arguments, response=response, request=request,
                                                     api=self.api, api_version=api_version, interface=self)
-
         return input_parameters
 
     @property
@@ -676,6 +691,7 @@ def __call__(self, request, response, api_version=None, **kwargs):
         else:
             exception_types = self.api.http.exception_handlers(api_version)
             exception_types = tuple(exception_types.keys()) if exception_types else ()
+        input_parameters = {}
         try:
             self.set_response_defaults(response, request)
 
@@ -691,9 +707,12 @@ def __call__(self, request, response, api_version=None, **kwargs):
                 return self.render_errors(errors, request, response)
 
             self.render_content(self.call_function(input_parameters), request, response, **kwargs)
-        except falcon.HTTPNotFound:
+            self.cleanup_parameters(input_parameters)
+        except falcon.HTTPNotFound as exception:
+            self.cleanup_parameters(input_parameters, exception=exception)
             return self.api.http.not_found(request, response, **kwargs)
         except exception_types as exception:
+            self.cleanup_parameters(input_parameters, exception=exception)
             handler = None
             exception_type = type(exception)
             if exception_type in exception_types:
@@ -710,6 +729,10 @@ def __call__(self, request, response, api_version=None, **kwargs):
                 raise exception
 
             handler(request=request, response=response, exception=exception, **kwargs)
+        except Exception as exception:
+            self.cleanup_parameters(input_parameters, exception=exception)
+            raise exception
+
 
     def documentation(self, add_to=None, version=None, prefix="", base_url="", url=""):
         """Returns the documentation specific to an HTTP interface"""

tests/test_decorators.py

@@ -934,6 +934,69 @@ def test(hug_timer):
     assert isinstance(hug.test.cli(test), float)
 
 
+def test_cli_with_class_directives():
+
+    @hug.directive()
+    class ClassDirective(object):
+
+        def __init__(self, *args, **kwargs):
+            self.test = 1
+
+    @hug.cli()
+    @hug.local(skip_directives=False)
+    def test(class_directive: ClassDirective):
+        return class_directive.test
+
+    assert test() == 1
+    assert hug.test.cli(test) == 1
+
+    class TestObject(object):
+        is_cleanup_launched = False
+        last_exception = None
+
+    @hug.directive()
+    class ClassDirectiveWithCleanUp(object):
+
+        def __init__(self, *args, **kwargs):
+            self.test_object = TestObject
+
+        def cleanup(self, exception):
+            self.test_object.is_cleanup_launched = True
+            self.test_object.last_exception = exception
+
+    @hug.cli()
+    @hug.local(skip_directives=False)
+    def test2(class_directive: ClassDirectiveWithCleanUp):
+        return class_directive.test_object.is_cleanup_launched
+
+    assert not hug.test.cli(test2)  # cleanup should be launched after running command
+    assert TestObject.is_cleanup_launched
+    assert TestObject.last_exception is None
+    TestObject.is_cleanup_launched = False
+    TestObject.last_exception = None
+    assert not test2()
+    assert TestObject.is_cleanup_launched
+    assert TestObject.last_exception is None
+
+    @hug.cli()
+    @hug.local(skip_directives=False)
+    def test_with_attribute_error(class_directive: ClassDirectiveWithCleanUp):
+        raise class_directive.test_object2
+
+    hug.test.cli(test_with_attribute_error)
+    assert TestObject.is_cleanup_launched
+    assert isinstance(TestObject.last_exception, AttributeError)
+    TestObject.is_cleanup_launched = False
+    TestObject.last_exception = None
+    try:
+        test_with_attribute_error()
+        assert False
+    except AttributeError:
+        assert True
+    assert TestObject.is_cleanup_launched
+    assert isinstance(TestObject.last_exception, AttributeError)
+
+
 def test_cli_with_named_directives():
     """Test to ensure you can pass named directives into the cli"""
     @hug.cli()