class Starlette:
def __init__(self,
debug: bool = False,
routes: typing.List[BaseRoute] = None) -> None:
self._debug = debug
self.router = Router(routes)
self.exception_middleware = ExceptionMiddleware(self.router,
debug=debug)
self.error_middleware = ServerErrorMiddleware(
self.exception_middleware, debug=debug)
@property
def routes(self) -> typing.List[BaseRoute]:
return self.router.routes
@property
def debug(self) -> bool:
return self._debug
@debug.setter
def debug(self, value: bool) -> None:
self._debug = value
self.exception_middleware.debug = value
self.error_middleware.debug = value
def on_event(self, event_type: str) -> typing.Callable:
return self.router.lifespan.on_event(event_type)
def mount(self, path: str, app: ASGIApp, name: str = None) -> None:
self.router.mount(path, app=app, name=name)
def host(self, host: str, app: ASGIApp, name: str = None) -> None:
self.router.host(host, app=app, name=name)
def add_middleware(self, middleware_class: type,
**kwargs: typing.Any) -> None:
self.error_middleware.app = middleware_class(self.error_middleware.app,
**kwargs)
def add_exception_handler(
self,
exc_class_or_status_code: typing.Union[int, typing.Type[Exception]],
handler: typing.Callable,
) -> None:
if exc_class_or_status_code in (500, Exception):
self.error_middleware.handler = handler
else:
self.exception_middleware.add_exception_handler(
exc_class_or_status_code, handler)
def add_event_handler(self, event_type: str,
func: typing.Callable) -> None:
self.router.lifespan.add_event_handler(event_type, func)
def add_route(
self,
path: str,
route: typing.Callable,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> None:
self.router.add_route(path,
route,
methods=methods,
name=name,
include_in_schema=include_in_schema)
def add_websocket_route(self,
path: str,
route: typing.Callable,
name: str = None) -> None:
self.router.add_websocket_route(path, route, name=name)
def exception_handler(
self, exc_class_or_status_code: typing.Union[int,
typing.Type[Exception]]
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.add_exception_handler(exc_class_or_status_code, func)
return func
return decorator
def route(
self,
path: str,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_route(
path,
func,
methods=methods,
name=name,
include_in_schema=include_in_schema,
)
return func
return decorator
def websocket_route(self, path: str, name: str = None) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_websocket_route(path, func, name=name)
return func
return decorator
def middleware(self, middleware_type: str) -> typing.Callable:
assert (middleware_type == "http"
), 'Currently only middleware("http") is supported.'
def decorator(func: typing.Callable) -> typing.Callable:
self.add_middleware(BaseHTTPMiddleware, dispatch=func)
return func
return decorator
def url_path_for(self, name: str, **path_params: str) -> URLPath:
return self.router.url_path_for(name, **path_params)
async def __call__(self, scope: Scope, receive: Receive,
send: Send) -> None:
scope["app"] = self
await self.error_middleware(scope, receive, send)
class Starlette:
def __init__(self,
debug: bool = False,
template_directory: str = None) -> None:
self._debug = debug
self.router = Router()
self.exception_middleware = ExceptionMiddleware(self.router,
debug=debug)
self.error_middleware = ServerErrorMiddleware(
self.exception_middleware, debug=debug)
self.lifespan_middleware = LifespanMiddleware(self.error_middleware)
self.schema_generator = None # type: typing.Optional[BaseSchemaGenerator]
self.template_env = self.load_template_env(template_directory)
@property
def routes(self) -> typing.List[BaseRoute]:
return self.router.routes
@property
def debug(self) -> bool:
return self._debug
@debug.setter
def debug(self, value: bool) -> None:
self._debug = value
self.exception_middleware.debug = value
self.error_middleware.debug = value
def load_template_env(self, template_directory: str = None) -> typing.Any:
if template_directory is None:
return None
# Import jinja2 lazily.
import jinja2
@jinja2.contextfunction
def url_for(context: dict, name: str,
**path_params: typing.Any) -> str:
request = context["request"]
return request.url_for(name, **path_params)
loader = jinja2.FileSystemLoader(str(template_directory))
env = jinja2.Environment(loader=loader, autoescape=True)
env.globals["url_for"] = url_for
return env
def get_template(self, name: str) -> typing.Any:
return self.template_env.get_template(name)
@property
def schema(self) -> dict:
assert self.schema_generator is not None
return self.schema_generator.get_schema(self.routes)
def on_event(self, event_type: str) -> typing.Callable:
return self.lifespan_middleware.on_event(event_type)
def mount(self, path: str, app: ASGIApp, name: str = None) -> None:
self.router.mount(path, app=app, name=name)
def host(self, host: str, app: ASGIApp, name: str = None) -> None:
self.router.host(host, app=app, name=name)
def add_middleware(self, middleware_class: type,
**kwargs: typing.Any) -> None:
self.error_middleware.app = middleware_class(self.error_middleware.app,
**kwargs)
def add_exception_handler(
self,
exc_class_or_status_code: typing.Union[int, typing.Type[Exception]],
handler: typing.Callable,
) -> None:
if exc_class_or_status_code in (500, Exception):
self.error_middleware.handler = handler
else:
self.exception_middleware.add_exception_handler(
exc_class_or_status_code, handler)
def add_event_handler(self, event_type: str,
func: typing.Callable) -> None:
self.lifespan_middleware.add_event_handler(event_type, func)
def add_route(
self,
path: str,
route: typing.Callable,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> None:
self.router.add_route(path,
route,
methods=methods,
name=name,
include_in_schema=include_in_schema)
def add_websocket_route(self,
path: str,
route: typing.Callable,
name: str = None) -> None:
self.router.add_websocket_route(path, route, name=name)
def exception_handler(
self, exc_class_or_status_code: typing.Union[int,
typing.Type[Exception]]
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.add_exception_handler(exc_class_or_status_code, func)
return func
return decorator
def route(
self,
path: str,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_route(
path,
func,
methods=methods,
name=name,
include_in_schema=include_in_schema,
)
return func
return decorator
def websocket_route(self, path: str, name: str = None) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_websocket_route(path, func, name=name)
return func
return decorator
def middleware(self, middleware_type: str) -> typing.Callable:
assert (middleware_type == "http"
), 'Currently only middleware("http") is supported.'
def decorator(func: typing.Callable) -> typing.Callable:
self.add_middleware(BaseHTTPMiddleware, dispatch=func)
return func
return decorator
def url_path_for(self, name: str, **path_params: str) -> URLPath:
return self.router.url_path_for(name, **path_params)
def __call__(self, scope: Scope) -> ASGIInstance:
scope["app"] = self
return self.lifespan_middleware(scope)
class Starlette:
"""
Creates an application instance.
**Parameters:**
* **debug** - Boolean indicating if debug tracebacks should be returned on errors.
* **routes** - A list of routes to serve incoming HTTP and WebSocket requests.
* **middleware** - A list of middleware to run for every request. A starlette
application will always automatically include two middleware classes.
`ServerErrorMiddleware` is added the very outermost middleware, to handle
any uncaught errors occuring anywhere in the entire stack.
`ExceptionMiddleware` is added as the very innermost middleware, to deal
with handled exception cases occuring in the routing or endpoints.
* **exception_handlers** - A dictionary mapping either integer status codes,
or exception class types onto callables which handle the exceptions.
Exception handler callables should be of the form `handler(request, exc) -> response`
and may be be either standard functions, or async functions.
* **on_startup** - A list of callables to run on application startup.
Startup handler callables do not take any arguments, and may be be either
standard functions, or async functions.
* **on_shutdown** - A list of callables to run on application shutdown.
Shutdown handler callables do not take any arguments, and may be be either
standard functions, or async functions.
"""
def __init__(
self,
debug: bool = False,
routes: typing.Sequence[BaseRoute] = None,
middleware: typing.Sequence[Middleware] = None,
exception_handlers: typing.Dict[typing.Union[int,
typing.Type[Exception]],
typing.Callable] = None,
on_startup: typing.Sequence[typing.Callable] = None,
on_shutdown: typing.Sequence[typing.Callable] = None,
lifespan: typing.Callable[["Starlette"], typing.AsyncGenerator] = None,
) -> None:
# The lifespan context function is a newer style that replaces
# on_startup / on_shutdown handlers. Use one or the other, not both.
assert lifespan is None or (
on_startup is None and on_shutdown is None
), "Use either 'lifespan' or 'on_startup'/'on_shutdown', not both."
self._debug = debug
self.state = State()
self.router = Router(routes,
on_startup=on_startup,
on_shutdown=on_shutdown,
lifespan=lifespan)
self.exception_handlers = ({} if exception_handlers is None else
dict(exception_handlers))
self.user_middleware = [] if middleware is None else list(middleware)
self.middleware_stack = self.build_middleware_stack()
def build_middleware_stack(self) -> ASGIApp:
debug = self.debug
error_handler = None
exception_handlers = {}
for key, value in self.exception_handlers.items():
if key in (500, Exception):
error_handler = value
else:
exception_handlers[key] = value
middleware = ([
Middleware(
ServerErrorMiddleware,
handler=error_handler,
debug=debug,
)
] + self.user_middleware + [
Middleware(
ExceptionMiddleware,
handlers=exception_handlers,
debug=debug,
)
])
app = self.router
for cls, options in reversed(middleware):
app = cls(app=app, **options)
return app
@property
def routes(self) -> typing.List[BaseRoute]:
return self.router.routes
@property
def debug(self) -> bool:
return self._debug
@debug.setter
def debug(self, value: bool) -> None:
self._debug = value
self.middleware_stack = self.build_middleware_stack()
def url_path_for(self, name: str, **path_params: str) -> URLPath:
return self.router.url_path_for(name, **path_params)
async def __call__(self, scope: Scope, receive: Receive,
send: Send) -> None:
scope["app"] = self
await self.middleware_stack(scope, receive, send)
# The following usages are now discouraged in favour of configuration
# during Starlette.__init__(...)
def on_event(self, event_type: str) -> typing.Callable:
return self.router.on_event(event_type)
def mount(self, path: str, app: ASGIApp, name: str = None) -> None:
self.router.mount(path, app=app, name=name)
def host(self, host: str, app: ASGIApp, name: str = None) -> None:
self.router.host(host, app=app, name=name)
def add_middleware(self, middleware_class: type,
**options: typing.Any) -> None:
self.user_middleware.insert(0, Middleware(middleware_class, **options))
self.middleware_stack = self.build_middleware_stack()
def add_exception_handler(
self,
exc_class_or_status_code: typing.Union[int, typing.Type[Exception]],
handler: typing.Callable,
) -> None:
self.exception_handlers[exc_class_or_status_code] = handler
self.middleware_stack = self.build_middleware_stack()
def add_event_handler(self, event_type: str,
func: typing.Callable) -> None:
self.router.add_event_handler(event_type, func)
def add_route(
self,
path: str,
route: typing.Callable,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> None:
self.router.add_route(path,
route,
methods=methods,
name=name,
include_in_schema=include_in_schema)
def add_websocket_route(self,
path: str,
route: typing.Callable,
name: str = None) -> None:
self.router.add_websocket_route(path, route, name=name)
def exception_handler(
self, exc_class_or_status_code: typing.Union[int,
typing.Type[Exception]]
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.add_exception_handler(exc_class_or_status_code, func)
return func
return decorator
def route(
self,
path: str,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_route(
path,
func,
methods=methods,
name=name,
include_in_schema=include_in_schema,
)
return func
return decorator
def websocket_route(self, path: str, name: str = None) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_websocket_route(path, func, name=name)
return func
return decorator
def middleware(self, middleware_type: str) -> typing.Callable:
assert (middleware_type == "http"
), 'Currently only middleware("http") is supported.'
def decorator(func: typing.Callable) -> typing.Callable:
self.add_middleware(BaseHTTPMiddleware, dispatch=func)
return func
return decorator
class Starlette:
def __init__(
self,
debug: bool = False,
routes: typing.List[BaseRoute] = None,
middleware: typing.List[Middleware] = None,
exception_handlers: typing.Dict[typing.Union[int,
typing.Type[Exception]],
typing.Callable] = None,
on_startup: typing.List[typing.Callable] = None,
on_shutdown: typing.List[typing.Callable] = None,
) -> None:
self._debug = debug
self.state = State()
self.router = Router(routes,
on_startup=on_startup,
on_shutdown=on_shutdown)
self.exception_handlers = ({} if exception_handlers is None else
dict(exception_handlers))
self.user_middleware = list(middleware or [])
self.middleware_stack = self.build_middleware_stack()
def build_middleware_stack(self) -> ASGIApp:
debug = self.debug
error_handler = None
exception_handlers = {}
for key, value in self.exception_handlers.items():
if key in (500, Exception):
error_handler = value
else:
exception_handlers[key] = value
server_errors = Middleware(
ServerErrorMiddleware,
options={
"handler": error_handler,
"debug": debug
},
)
exceptions = Middleware(
ExceptionMiddleware,
options={
"handlers": exception_handlers,
"debug": debug
},
)
middleware = [server_errors] + self.user_middleware + [exceptions]
app = self.router
for cls, options, enabled in reversed(middleware):
if enabled:
app = cls(app=app, **options)
return app
@property
def routes(self) -> typing.List[BaseRoute]:
return self.router.routes
@property
def debug(self) -> bool:
return self._debug
@debug.setter
def debug(self, value: bool) -> None:
self._debug = value
self.middleware_stack = self.build_middleware_stack()
def on_event(self, event_type: str) -> typing.Callable:
return self.router.lifespan.on_event(event_type)
def mount(self, path: str, app: ASGIApp, name: str = None) -> None:
self.router.mount(path, app=app, name=name)
def host(self, host: str, app: ASGIApp, name: str = None) -> None:
self.router.host(host, app=app, name=name)
def add_middleware(self, middleware_class: type,
**kwargs: typing.Any) -> None:
self.user_middleware.insert(
0, Middleware(middleware_class, options=kwargs))
self.middleware_stack = self.build_middleware_stack()
def add_exception_handler(
self,
exc_class_or_status_code: typing.Union[int, typing.Type[Exception]],
handler: typing.Callable,
) -> None:
self.exception_handlers[exc_class_or_status_code] = handler
self.middleware_stack = self.build_middleware_stack()
def add_event_handler(self, event_type: str,
func: typing.Callable) -> None:
self.router.lifespan.add_event_handler(event_type, func)
def add_route(
self,
path: str,
route: typing.Callable,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> None:
self.router.add_route(path,
route,
methods=methods,
name=name,
include_in_schema=include_in_schema)
def add_websocket_route(self,
path: str,
route: typing.Callable,
name: str = None) -> None:
self.router.add_websocket_route(path, route, name=name)
def exception_handler(
self, exc_class_or_status_code: typing.Union[int,
typing.Type[Exception]]
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.add_exception_handler(exc_class_or_status_code, func)
return func
return decorator
def route(
self,
path: str,
methods: typing.List[str] = None,
name: str = None,
include_in_schema: bool = True,
) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_route(
path,
func,
methods=methods,
name=name,
include_in_schema=include_in_schema,
)
return func
return decorator
def websocket_route(self, path: str, name: str = None) -> typing.Callable:
def decorator(func: typing.Callable) -> typing.Callable:
self.router.add_websocket_route(path, func, name=name)
return func
return decorator
def middleware(self, middleware_type: str) -> typing.Callable:
assert (middleware_type == "http"
), 'Currently only middleware("http") is supported.'
def decorator(func: typing.Callable) -> typing.Callable:
self.add_middleware(BaseHTTPMiddleware, dispatch=func)
return func
return decorator
def url_path_for(self, name: str, **path_params: str) -> URLPath:
return self.router.url_path_for(name, **path_params)
async def __call__(self, scope: Scope, receive: Receive,
send: Send) -> None:
scope["app"] = self
await self.middleware_stack(scope, receive, send)