Implement providers traversal in first precision

src/dependency_injector/containers.pyi

@@ -7,9 +7,12 @@ from typing import (
     Union,
     ClassVar,
     Callable as _Callable,
+    Sequence,
     Iterable,
+    Iterator,
     TypeVar,
     Awaitable,
+    overload,
 )
 
 from .providers import Provider
@@ -41,6 +44,12 @@ class Container:
     def init_resources(self) -> Optional[Awaitable]: ...
     def shutdown_resources(self) -> Optional[Awaitable]: ...
 
+    @overload
+    def traverse_providers(self, types: Optional[Sequence[Type]] = None) -> Iterator[Provider]: ...
+    @classmethod
+    @overload
+    def traverse_providers(cls, types: Optional[Sequence[Type]] = None) -> Iterator[Provider]: ...
+
 
 class DynamicContainer(Container): ...
 

src/dependency_injector/containers.pyx

@@ -10,16 +10,7 @@ except ImportError:
 
 import six
 
-from .errors import Error
-from .providers cimport (
-    Provider,
-    Object,
-    Resource,
-    Dependency,
-    DependenciesContainer,
-    Container as ContainerProvider,
-    deepcopy,
-)
+from . import providers, errors
 
 
 if sys.version_info[:2] >= (3, 6):
@@ -68,13 +59,13 @@ class DynamicContainer(object):
 
         :rtype: None
         """
-        self.provider_type = Provider
+        self.provider_type = providers.Provider
         self.providers = {}
         self.overridden = tuple()
         self.declarative_parent = None
         self.wired_to_modules = []
         self.wired_to_packages = []
-        self.__self__ = Object(self)
+        self.__self__ = providers.Object(self)
         super(DynamicContainer, self).__init__()
 
     def __deepcopy__(self, memo):
@@ -84,11 +75,11 @@ class DynamicContainer(object):
             return copied
 
         copied = self.__class__()
-        copied.provider_type = Provider
-        copied.overridden = deepcopy(self.overridden, memo)
+        copied.provider_type = providers.Provider
+        copied.overridden = providers.deepcopy(self.overridden, memo)
         copied.declarative_parent = self.declarative_parent
 
-        for name, provider in deepcopy(self.providers, memo).items():
+        for name, provider in providers.deepcopy(self.providers, memo).items():
             setattr(copied, name, provider)
 
         return copied
@@ -107,7 +98,7 @@ class DynamicContainer(object):
 
         :rtype: None
         """
-        if isinstance(value, Provider) and name != '__self__':
+        if isinstance(value, providers.Provider) and name != '__self__':
             _check_provider_type(self, value)
             self.providers[name] = value
         super(DynamicContainer, self).__setattr__(name, value)
@@ -140,9 +131,13 @@ class DynamicContainer(object):
         return {
             name: provider
             for name, provider in self.providers.items()
-            if isinstance(provider, (Dependency, DependenciesContainer))
+            if isinstance(provider, (providers.Dependency, providers.DependenciesContainer))
         }
 
+    def traverse_providers(self, types=None):
+        """Return providers traversal generator."""
+        yield from providers.traverse(*self.providers.values(), types=types)
+
     def set_providers(self, **providers):
         """Set container providers.
 
@@ -167,8 +162,8 @@ class DynamicContainer(object):
         :rtype: None
         """
         if overriding is self:
-            raise Error('Container {0} could not be overridden '
-                        'with itself'.format(self))
+            raise errors.Error('Container {0} could not be overridden '
+                               'with itself'.format(self))
 
         self.overridden += (overriding,)
 
@@ -197,7 +192,7 @@ class DynamicContainer(object):
         :rtype: None
         """
         if not self.overridden:
-            raise Error('Container {0} is not overridden'.format(self))
+            raise errors.Error('Container {0} is not overridden'.format(self))
 
         self.overridden = self.overridden[:-1]
 
@@ -245,7 +240,7 @@ class DynamicContainer(object):
         """Initialize all container resources."""
         futures = []
         for provider in self.providers.values():
-            if not isinstance(provider, Resource):
+            if not isinstance(provider, providers.Resource):
                 continue
 
             resource = provider.init()
@@ -260,7 +255,7 @@ class DynamicContainer(object):
         """Shutdown all container resources."""
         futures = []
         for provider in self.providers.values():
-            if not isinstance(provider, Resource):
+            if not isinstance(provider, providers.Resource):
                 continue
 
             shutdown = provider.shutdown()
@@ -274,7 +269,7 @@ class DynamicContainer(object):
     def apply_container_providers_overridings(self):
         """Apply container providers' overridings."""
         for provider in self.providers.values():
-            if not isinstance(provider, ContainerProvider):
+            if not isinstance(provider, providers.Container):
                 continue
             provider.apply_overridings()
 
@@ -293,7 +288,7 @@ class DeclarativeContainerMetaClass(type):
         cls_providers = {
             name: provider
             for name, provider in six.iteritems(attributes)
-            if isinstance(provider, Provider)
+            if isinstance(provider, providers.Provider)
         }
 
         inherited_providers = {
@@ -303,18 +298,18 @@ class DeclarativeContainerMetaClass(type):
             for name, provider in six.iteritems(base.providers)
         }
 
-        providers = {}
-        providers.update(inherited_providers)
-        providers.update(cls_providers)
+        all_providers = {}
+        all_providers.update(inherited_providers)
+        all_providers.update(cls_providers)
 
         attributes['containers'] = containers
         attributes['inherited_providers'] = inherited_providers
         attributes['cls_providers'] = cls_providers
-        attributes['providers'] = providers
+        attributes['providers'] = all_providers
 
         cls = <type>type.__new__(mcs, class_name, bases, attributes)
 
-        cls.__self__ = Object(cls)
+        cls.__self__ = providers.Object(cls)
 
         for provider in six.itervalues(cls.providers):
             _check_provider_type(cls, provider)
@@ -335,7 +330,7 @@ class DeclarativeContainerMetaClass(type):
 
         :rtype: None
         """
-        if isinstance(value, Provider) and name != '__self__':
+        if isinstance(value, providers.Provider) and name != '__self__':
             _check_provider_type(cls, value)
             cls.providers[name] = value
             cls.cls_providers[name] = value
@@ -370,9 +365,13 @@ class DeclarativeContainerMetaClass(type):
         return {
             name: provider
             for name, provider in cls.providers.items()
-            if isinstance(provider, (Dependency, DependenciesContainer))
+            if isinstance(provider, (providers.Dependency, providers.DependenciesContainer))
         }
 
+    def traverse_providers(cls, types=None):
+        """Return providers traversal generator."""
+        yield from providers.traverse(*cls.providers.values(), types=types)
+
 
 @six.add_metaclass(DeclarativeContainerMetaClass)
 class DeclarativeContainer(object):
@@ -388,7 +387,7 @@ class DeclarativeContainer(object):
 
     __IS_CONTAINER__ = True
 
-    provider_type = Provider
+    provider_type = providers.Provider
     """Type of providers that could be placed in container.
 
     :type: type
@@ -446,7 +445,7 @@ class DeclarativeContainer(object):
         container = cls.instance_type()
         container.provider_type = cls.provider_type
         container.declarative_parent = cls
-        container.set_providers(**deepcopy(cls.providers))
+        container.set_providers(**providers.deepcopy(cls.providers))
         container.override_providers(**overriding_providers)
         container.apply_container_providers_overridings()
         return container
@@ -464,8 +463,8 @@ class DeclarativeContainer(object):
         :rtype: None
         """
         if issubclass(cls, overriding):
-            raise Error('Container {0} could not be overridden '
-                        'with itself or its subclasses'.format(cls))
+            raise errors.Error('Container {0} could not be overridden '
+                               'with itself or its subclasses'.format(cls))
 
         cls.overridden += (overriding,)
 
@@ -482,7 +481,7 @@ class DeclarativeContainer(object):
         :rtype: None
         """
         if not cls.overridden:
-            raise Error('Container {0} is not overridden'.format(cls))
+            raise errors.Error('Container {0} is not overridden'.format(cls))
 
         cls.overridden = cls.overridden[:-1]
 
@@ -559,7 +558,7 @@ def copy(object container):
     def _decorator(copied_container):
         memo = _get_providers_memo(copied_container.cls_providers, container.providers)
 
-        providers_copy = deepcopy(container.providers, memo)
+        providers_copy = providers.deepcopy(container.providers, memo)
         for name, provider in six.iteritems(providers_copy):
             setattr(copied_container, name, provider)
 
@@ -580,8 +579,8 @@ cpdef bint is_container(object instance):
 
 cpdef object _check_provider_type(object container, object provider):
     if not isinstance(provider, container.provider_type):
-        raise Error('{0} can contain only {1} '
-                    'instances'.format(container, container.provider_type))
+        raise errors.Error('{0} can contain only {1} '
+                           'instances'.format(container, container.provider_type))
 
 
 cpdef bint _isawaitable(object instance):

src/dependency_injector/providers.pyi

@@ -13,6 +13,7 @@ from typing import (
     Dict as _Dict,
     Optional,
     Union,
+    Sequence,
     Coroutine as _Coroutine,
     Iterator as _Iterator,
     AsyncIterator as _AsyncIterator,
@@ -68,6 +69,8 @@ class Provider(Generic[T]):
     def is_async_mode_enabled(self) -> bool: ...
     def is_async_mode_disabled(self) -> bool: ...
     def is_async_mode_undefined(self) -> bool: ...
+    @property
+    def providers_traversal(self) -> _Iterator[Provider]: ...
     def _copy_overridings(self, copied: Provider, memo: Optional[_Dict[Any, Any]]) -> None: ...
 
 
@@ -382,6 +385,9 @@ def deepcopy(instance: Any, memo: Optional[_Dict[Any, Any]] = None): Any: ...
 def merge_dicts(dict1: _Dict[Any, Any], dict2: _Dict[Any, Any]) -> _Dict[Any, Any]: ...
 
 
+def traverse(*providers: Provider, types: Optional[Sequence[Type]]=None) -> _Iterator[Provider]: ...
+
+
 if yaml:
     class YamlLoader(yaml.SafeLoader): ...
 else:

src/dependency_injector/providers.pyx

@@ -363,6 +363,11 @@ cdef class Provider(object):
         """Check if async mode is undefined."""
         return self.__async_mode == ASYNC_MODE_UNDEFINED
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        yield from self.overridden
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Providing strategy implementation.
 
@@ -423,6 +428,13 @@ cdef class Object(Provider):
         """
         return self.__str__()
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        if isinstance(self.__provides, Provider):
+            yield self.__provides
+        yield from super().providers_traversal
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return provided instance.
 
@@ -487,6 +499,12 @@ cdef class Delegate(Provider):
         """Return provider."""
         return self.__provides
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        yield self.__provides
+        yield from super().providers_traversal
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return provided instance.
 
@@ -619,6 +637,13 @@ cdef class Dependency(Provider):
         """Return default provider."""
         return self.__default
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        if self.__default is not UNDEFINED:
+            yield self.__default
+        yield from super().providers_traversal
+
     def provided_by(self, provider):
         """Set external dependency provider.
 
@@ -790,6 +815,12 @@ cdef class DependenciesContainer(Object):
             child.reset_override()
         super(DependenciesContainer, self).reset_override()
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        yield from self.providers.values()
+        yield from super().providers_traversal
+
     cpdef object _override_providers(self, object container):
         """Override providers with providers from provided container."""
         for name, dependency_provider in container.providers.items():
@@ -998,6 +1029,14 @@ cdef class Callable(Provider):
         self.__kwargs_len = len(self.__kwargs)
         return self
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        yield from filter(is_provider, [self.provides])
+        yield from filter(is_provider, self.args)
+        yield from filter(is_provider, self.kwargs.values())
+        yield from super().providers_traversal
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return result of provided callable's call."""
         return __callable_call(self, args, kwargs)
@@ -1442,6 +1481,12 @@ cdef class ConfigurationOption(Provider):
 
         self.override(value)
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        # TODO: revise
+        yield from super().providers_traversal
+
     def _is_strict_mode_enabled(self):
         return self.__root.__strict
 
@@ -1979,6 +2024,15 @@ cdef class Factory(Provider):
         self.__attributes_len = len(self.__attributes)
         return self
 
+    @property
+    def providers_traversal(self):
+        """Return providers traversal generator."""
+        yield from filter(is_provider, [self.provides])
+        yield from filter(is_provider, self.args)
+        yield from filter(is_provider, self.kwargs.values())
+        yield from filter(is_provider, self.attributes.values())
+        yield from super().providers_traversal
+
     cpdef object _provide(self, tuple args, dict kwargs):
         """Return new instance."""
         return __factory_call(self, args, kwargs)
@@ -3846,6 +3900,29 @@ def merge_dicts(dict1, dict2):
     return result
 
 
+def traverse(*providers, types=None):
+    """Return providers traversal generator."""
+    visited = set()
+    to_visit = set(providers)
+
+    if types:
+        types = tuple(types)
+
+    while len(to_visit) > 0:
+        visiting = to_visit.pop()
+        visited.add(visiting)
+
+        for child in visiting.providers_traversal:
+            if child in visited:
+                continue
+            to_visit.add(child)
+
+        if types and not isinstance(visiting, types):
+            continue
+
+        yield visiting
+
+
 def isawaitable(obj):
     """Check if object is a coroutine function.
 

tests/unit/containers/test_declarative_py2_py3.py

@@ -431,3 +431,90 @@ class DeclarativeContainerTests(unittest.TestCase):
         self.assertIsInstance(container.p31, providers.Provider)
         self.assertIsInstance(container.p32, providers.Provider)
         self.assertIs(container.p11.last_overriding, provider)
+
+
+class ProvidersTraversalTests(unittest.TestCase):
+
+    def test_nested_providers(self):
+        class Container(containers.DeclarativeContainer):
+            obj_factory = providers.DelegatedFactory(
+                dict,
+                foo=providers.Resource(
+                    dict,
+                    foo='bar'
+                ),
+                bar=providers.Resource(
+                    dict,
+                    foo='bar'
+                )
+            )
+
+        container = Container()
+        all_providers = list(container.traverse_providers())
+
+        self.assertIn(container.obj_factory, all_providers)
+        self.assertIn(container.obj_factory.kwargs['foo'], all_providers)
+        self.assertIn(container.obj_factory.kwargs['bar'], all_providers)
+        self.assertEqual(len(all_providers), 3)
+
+    def test_nested_providers_class(self):
+        class Container(containers.DeclarativeContainer):
+            obj_factory = providers.DelegatedFactory(
+                dict,
+                foo=providers.Resource(
+                    dict,
+                    foo='bar'
+                ),
+                bar=providers.Resource(
+                    dict,
+                    foo='bar'
+                )
+            )
+
+        all_providers = list(Container.traverse_providers())
+
+        self.assertIn(Container.obj_factory, all_providers)
+        self.assertIn(Container.obj_factory.kwargs['foo'], all_providers)
+        self.assertIn(Container.obj_factory.kwargs['bar'], all_providers)
+        self.assertEqual(len(all_providers), 3)
+
+    def test_nested_providers_with_filtering(self):
+        class Container(containers.DeclarativeContainer):
+            obj_factory = providers.DelegatedFactory(
+                dict,
+                foo=providers.Resource(
+                    dict,
+                    foo='bar'
+                ),
+                bar=providers.Resource(
+                    dict,
+                    foo='bar'
+                )
+            )
+
+        container = Container()
+        all_providers = list(container.traverse_providers(types=[providers.Resource]))
+
+        self.assertIn(container.obj_factory.kwargs['foo'], all_providers)
+        self.assertIn(container.obj_factory.kwargs['bar'], all_providers)
+        self.assertEqual(len(all_providers), 2)
+
+    def test_nested_providers_class_with_filtering(self):
+        class Container(containers.DeclarativeContainer):
+            obj_factory = providers.DelegatedFactory(
+                dict,
+                foo=providers.Resource(
+                    dict,
+                    foo='bar'
+                ),
+                bar=providers.Resource(
+                    dict,
+                    foo='bar'
+                )
+            )
+
+        all_providers = list(Container.traverse_providers(types=[providers.Resource]))
+
+        self.assertIn(Container.obj_factory.kwargs['foo'], all_providers)
+        self.assertIn(Container.obj_factory.kwargs['bar'], all_providers)
+        self.assertEqual(len(all_providers), 2)