def __new__(cls, class_name, bases, namespace):
if not bases:
namespace["__dependencies__"] = {}
namespace["__wrapped__"] = None # Doctest module compatibility.
namespace["_subs_tree"] = None # Typing module compatibility.
return type.__new__(cls, class_name, bases, namespace)
_check_inheritance(bases, Injector)
ns = {}
for attr in ("__module__", "__doc__", "__weakref__", "__qualname__"):
try:
ns[attr] = namespace.pop(attr)
except KeyError:
pass
for name in namespace:
_check_dunder_name(name)
_check_attrs_redefinition(name)
dependencies = {}
for base in reversed(bases):
dependencies.update(base.__dependencies__)
for name, dep in namespace.items():
dependencies[name] = _make_dependency_spec(name, dep)
_check_loops(class_name, dependencies)
_check_circles(dependencies)
ns["__dependencies__"] = dependencies
return type.__new__(cls, class_name, bases, ns)
def __getattr__(cls, attrname):
__tracebackhide__ = True
cache, cached = {"__self__": cls}, {"__self__"}
current_attr, attrs_stack = attrname, [attrname]
have_default = False
while attrname not in cache:
spec = cls.__dependencies__.get(current_attr)
if spec is None:
if have_default:
cached.add(current_attr)
current_attr = attrs_stack.pop()
have_default = False
continue
if len(attrs_stack) > 1:
message = "{!r} can not resolve attribute {!r} while building {!r}".format( # noqa: E501
cls.__name__, current_attr, attrs_stack.pop())
else:
message = "{!r} can not resolve attribute {!r}".format(
cls.__name__, current_attr)
raise DependencyError(message)
marker, attribute, args, have_defaults = spec
if set(args).issubset(cached):
kwargs = {k: cache[k] for k in args if k in cache}
try:
cache[current_attr] = attribute(**kwargs)
except _Replace as replace:
_deep_replace_dependency(cls, current_attr, replace)
_check_loops(cls.__name__, cls.__dependencies__)
_check_circles(cls.__dependencies__)
continue
cached.add(current_attr)
current_attr = attrs_stack.pop()
have_default = False
continue
for n, arg in enumerate(args, 1):
if arg not in cached:
attrs_stack.append(current_attr)
current_attr = arg
have_default = False if n < have_defaults else True
break
return cache[attrname]
def __getattr__(cls, attrname):
__tracebackhide__ = True
cache, cached = {"__self__": cls}, {"__self__"}
current_attr, attrs_stack = attrname, [attrname]
have_default = False
replaced_dependencies = {}
while attrname not in cache:
spec = cls.__dependencies__.get(current_attr)
if spec is None:
if have_default:
cached.add(current_attr)
current_attr = attrs_stack.pop()
have_default = False
continue
if len(attrs_stack) > 1:
message = "{!r} can not resolve attribute {!r} while building {!r}".format( # noqa: E501
cls.__name__, current_attr, attrs_stack.pop()
)
else:
message = "{!r} can not resolve attribute {!r}".format(
cls.__name__, current_attr
)
raise DependencyError(message)
marker, attribute, args, have_defaults = spec
if set(args).issubset(cached):
kwargs = {k: cache[k] for k in args if k in cache}
try:
dependency = attribute(**kwargs)
if ('nested' not in marker
and inspect.isclass(dependency)
and not current_attr.endswith("_class")):
spec = _make_init_spec(dependency)
replaced_dependency = _replace_dependency(cls, current_attr, spec)
replaced_dependencies[current_attr] = replaced_dependency
continue
elif isinstance(dependency, This):
spec = _make_this_spec(dependency)
replaced_dependency = _replace_dependency(cls, current_attr, spec)
replaced_dependencies[current_attr] = replaced_dependency
continue
else:
cache[current_attr] = dependency
except _Replace as replace:
_deep_replace_dependency(cls, current_attr, replace)
_check_loops(cls.__name__, cls.__dependencies__)
_check_circles(cls.__dependencies__)
continue
cached.add(current_attr)
current_attr = attrs_stack.pop()
have_default = False
continue
for n, arg in enumerate(args, 1):
if arg not in cached:
attrs_stack.append(current_attr)
current_attr = arg
have_default = False if n < have_defaults else True
break
# Restore @value dependencies that returned a class from the result class
# to their defining function
for attr, dep in replaced_dependencies.items():
cls.__dependencies__[attr] = dep
return cache[attrname]
def _replace_dependency(injector, current_attr, spec):
replaced_dependency = injector.__dependencies__[current_attr]
injector.__dependencies__[current_attr] = spec
_check_loops(injector.__name__, injector.__dependencies__)
_check_circles(injector.__dependencies__)
return replaced_dependency
