Gateway class

This is the reference for the Gateway that contains all the parameters, attributes and functions.

How to import

from esmerald import Gateway

esmerald.Gateway

Gateway(path=None, *, handler, name=None, include_in_schema=True, parent=None, dependencies=None, middleware=None, interceptors=None, permissions=None, exception_handlers=None, deprecated=None, is_from_router=False, security=None, tags=None, operation_id=None)

Bases: Path, Dispatcher, BaseMiddleware, GatewayUtil

Gateway object class used by Esmerald routes.

The Gateway act as a brigde between the router handlers and the main Esmerald routing system.

Read more about Gateway and how to use it.

Example

from esmerald import Esmerald. get

@get()
async def home() -> str:
    return "Hello, World!"

Gateway(path="/home", handler=home)

PARAMETER	DESCRIPTION
path	Relative path of the Gateway. The path can contain parameters in a dictionary like format and if the path is not provided, it will default to /. Example Gateway() Example with parameters Gateway(path="/{age: int}") TYPE: Optional[str] DEFAULT: None
handler	An instance of handler. TYPE: Union[HTTPHandler, View]
name	The name for the Gateway. The name can be reversed by path_for(). TYPE: Optional[str] DEFAULT: None
include_in_schema	Boolean flag indicating if it should be added to the OpenAPI docs. TYPE: bool DEFAULT: True
parent	Who owns the Gateway. If not specified, the application automatically it assign it. This is directly related with the application levels. TYPE: Optional[ParentType] DEFAULT: None
dependencies	A dictionary of string and Inject instances enable application level dependency injection. TYPE: Optional[Dependencies] DEFAULT: None
middleware	A list of middleware to run for every request. The middlewares of a Gateway will be checked from top-down or Lilya Middleware as they are both converted internally. Read more about Python Protocols. TYPE: Optional[List[Middleware]] DEFAULT: None
interceptors	A list of interceptors to serve the application incoming requests (HTTP and Websockets). TYPE: Optional[Sequence[Interceptor]] DEFAULT: None
permissions	A list of permissions to serve the application incoming requests (HTTP and Websockets). TYPE: Optional[Sequence[Permission]] DEFAULT: None
exception_handlers	A dictionary of exception types (or custom exceptions) and the handler functions on an application top level. Exception handler callables should be of the form of handler(request, exc) -> response and may be be either standard functions, or async functions. TYPE: Optional[ExceptionHandlerMap] DEFAULT: None
deprecated	Boolean flag for indicating the deprecation of the Gateway and to display it in the OpenAPI documentation.. TYPE: Optional[bool] DEFAULT: None
is_from_router	Used by the .add_router() function of the Esmerald class indicating if the Gateway is coming from a router. TYPE: bool DEFAULT: False
security	Used by OpenAPI definition, the security must be compliant with the norms. Esmerald offers some out of the box solutions where this is implemented. The Esmerald security is available to automatically used. The security can be applied also on a level basis. For custom security objects, you must subclass esmerald.openapi.security.base.HTTPBase object. TYPE: Optional[Sequence[SecurityScheme]] DEFAULT: None
tags	A list of strings tags to be applied to the path operation. It will be added to the generated OpenAPI documentation. Note almost everything in Esmerald can be done in levels, which means these tags on a Esmerald instance, means it will be added to every route even if those routes also contain tags. TYPE: Optional[Sequence[str]] DEFAULT: None
operation_id	Unique operation id that allows distinguishing the same handler in different Gateways. Used for OpenAPI purposes. TYPE: Optional[str] DEFAULT: None

Source code in esmerald/routing/gateways.py

def __init__(
    self,
    path: Annotated[
        Optional[str],
        Doc(
            """
            Relative path of the `Gateway`.
            The path can contain parameters in a dictionary like format
            and if the path is not provided, it will default to `/`.

            **Example**

            ```python
            Gateway()
            ```

            **Example with parameters**

            ```python
            Gateway(path="/{age: int}")
            ```
            """
        ),
    ] = None,
    *,
    handler: Annotated[
        Union["HTTPHandler", View],
        Doc(
            """
        An instance of [handler](https://esmerald.dev/routing/handlers/#http-handlers).
        """
        ),
    ],
    name: Annotated[
        Optional[str],
        Doc(
            """
            The name for the Gateway. The name can be reversed by `path_for()`.
            """
        ),
    ] = None,
    include_in_schema: Annotated[
        bool,
        Doc(
            """
            Boolean flag indicating if it should be added to the OpenAPI docs.
            """
        ),
    ] = True,
    parent: Annotated[
        Optional["ParentType"],
        Doc(
            """
            Who owns the Gateway. If not specified, the application automatically it assign it.

            This is directly related with the [application levels](https://esmerald.dev/application/levels/).
            """
        ),
    ] = None,
    dependencies: Annotated[
        Optional["Dependencies"],
        Doc(
            """
            A dictionary of string and [Inject](https://esmerald.dev/dependencies/) instances enable application level dependency injection.
            """
        ),
    ] = None,
    middleware: Annotated[
        Optional[List["Middleware"]],
        Doc(
            """
            A list of middleware to run for every request. The middlewares of a Gateway will be checked from top-down or [Lilya Middleware](https://www.lilya.dev/middleware/) as they are both converted internally. Read more about [Python Protocols](https://peps.python.org/pep-0544/).
            """
        ),
    ] = None,
    interceptors: Annotated[
        Optional[Sequence["Interceptor"]],
        Doc(
            """
            A list of [interceptors](https://esmerald.dev/interceptors/) to serve the application incoming requests (HTTP and Websockets).
            """
        ),
    ] = None,
    permissions: Annotated[
        Optional[Sequence["Permission"]],
        Doc(
            """
            A list of [permissions](https://esmerald.dev/permissions/) to serve the application incoming requests (HTTP and Websockets).
            """
        ),
    ] = None,
    exception_handlers: Annotated[
        Optional["ExceptionHandlerMap"],
        Doc(
            """
            A dictionary of [exception types](https://esmerald.dev/exceptions/) (or custom exceptions) and the handler functions on an application top level. Exception handler callables should be of the form of `handler(request, exc) -> response` and may be be either standard functions, or async functions.
            """
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            """
            Boolean flag for indicating the deprecation of the Gateway and to display it
            in the OpenAPI documentation..
            """
        ),
    ] = None,
    is_from_router: Annotated[
        bool,
        Doc(
            """
            Used by the `.add_router()` function of the `Esmerald` class indicating if the
            Gateway is coming from a router.
            """
        ),
    ] = False,
    security: Annotated[
        Optional[Sequence["SecurityScheme"]],
        Doc(
            """
            Used by OpenAPI definition, the security must be compliant with the norms.
            Esmerald offers some out of the box solutions where this is implemented.

            The [Esmerald security](https://esmerald.dev/openapi/) is available to automatically used.

            The security can be applied also on a [level basis](https://esmerald.dev/application/levels/).

            For custom security objects, you **must** subclass
            `esmerald.openapi.security.base.HTTPBase` object.
            """
        ),
    ] = None,
    tags: Annotated[
        Optional[Sequence[str]],
        Doc(
            """
            A list of strings tags to be applied to the *path operation*.

            It will be added to the generated OpenAPI documentation.

            **Note** almost everything in Esmerald can be done in [levels](https://esmerald.dev/application/levels/), which means
            these tags on a Esmerald instance, means it will be added to every route even
            if those routes also contain tags.
            """
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            """
            Unique operation id that allows distinguishing the same handler in different Gateways.

            Used for OpenAPI purposes.
            """
        ),
    ] = None,
) -> None:
    if not path:
        path = "/"
    if is_class_and_subclass(handler, View):
        handler = handler(parent=self)  # type: ignore

    if not is_from_router:
        self.path = clean_path(path + handler.path)
    else:
        self.path = clean_path(path)

    self.methods = getattr(handler, "http_methods", None)

    if not name:
        if not isinstance(handler, View):
            name = clean_string(handler.fn.__name__)
        else:
            name = clean_string(handler.__class__.__name__)

    # Handle middleware
    self.middleware = middleware or []
    self._middleware: List["Middleware"] = self.handle_middleware(
        handler=handler, base_middleware=self.middleware
    )
    super().__init__(
        path=self.path,
        handler=cast(Callable, handler),
        include_in_schema=include_in_schema,
        name=name,
        methods=self.methods,
        middleware=self._middleware,
        exception_handlers=exception_handlers,
    )
    """
    A "bridge" to a handler and router mapping functionality.
    Since the default Lilya Route handler does not understand the Esmerald handlers,
    the Gateway bridges both functionalities and adds an extra "flair" to be compliant with both class based views and decorated function views.
    """
    self._interceptors: Union[List["Interceptor"], "VoidType"] = Void
    self.name = name
    self.handler = cast("Callable", handler)
    self.dependencies = dependencies or {}
    self.interceptors: Sequence["Interceptor"] = interceptors or []
    self.permissions: Sequence["Permission"] = permissions or []  # type: ignore
    self.response_class = None
    self.response_cookies = None
    self.response_headers = None
    self.deprecated = deprecated
    self.parent = parent
    self.security = security
    self.tags = tags or []
    (handler.path_regex, handler.path_format, handler.param_convertors, _) = compile_path(
        self.path
    )
    self.operation_id = operation_id

    if self.is_handler(self.handler):  # type: ignore
        self.handler.name = self.name

        if self.operation_id or handler.operation_id is not None:
            handler_id = self.generate_operation_id(
                name=self.name, handler=self.handler  # type: ignore
            )
            self.operation_id = f"{operation_id}_{handler_id}" if operation_id else handler_id

        elif not handler.operation_id:
            handler.operation_id = self.generate_operation_id(
                name=self.name, handler=self.handler  # type: ignore
            )

path instance-attribute

path = clean_path(path + path)

handler instance-attribute

handler = cast('Callable', handler)

parent instance-attribute

parent = parent

dependencies instance-attribute

dependencies = dependencies or {}

middleware instance-attribute

middleware = middleware or []

interceptors instance-attribute

interceptors = interceptors or []

permissions instance-attribute

permissions = permissions or []

exception_handlers instance-attribute

exception_handlers = {} if exception_handlers is None else dict(exception_handlers)

include_in_schema instance-attribute

include_in_schema = include_in_schema

deprecated instance-attribute

deprecated = deprecated

security instance-attribute

security = security

tags instance-attribute

tags = tags or []