nexusrpc.handler.OperationHandler

class documentation

class OperationHandler(ABC, Generic[InputT, OutputT]):

Known subclasses: nexusrpc.handler._operation_handler.SyncOperationHandler

Base class for an operation handler in a Nexus service implementation.

To define a Nexus operation handler, create a method on your service handler class that takes self and returns an instance of OperationHandler, and apply the @nexusrpc.handler.operation_handler decorator.

To create an operation handler that is limited to returning synchronously, use @nexusrpc.handler.SyncOperationHandler to create the instance of OperationHandler from the start method.

Method	`cancel`	Cancel the operation.
Method	`fetch_info`	Return information about the current status of the operation.
Method	`fetch_result`	Return the result of the operation.
Method	`start`	Start the operation, completing either synchronously or asynchronously.

@abstractmethod

def cancel(self, ctx: CancelOperationContext, token: str) -> None | Awaitable[None]: ¶

overridden in nexusrpc.handler._operation_handler.SyncOperationHandler

Cancel the operation.

@abstractmethod

def fetch_info(self, ctx: FetchOperationInfoContext, token: str) -> OperationInfo | Awaitable[OperationInfo]: ¶

overridden in nexusrpc.handler._operation_handler.SyncOperationHandler

Return information about the current status of the operation.

@abstractmethod

def fetch_result(self, ctx: FetchOperationResultContext, token: str) -> OutputT | Awaitable[OutputT]: ¶

overridden in nexusrpc.handler._operation_handler.SyncOperationHandler

Return the result of the operation.

@abstractmethod

def start(self, ctx: StartOperationContext, input: InputT) ->

StartOperationResultSync[OutputT] | Awaitable[StartOperationResultSync[OutputT]] | StartOperationResultAsync | Awaitable[StartOperationResultAsync]

: ¶

overridden in nexusrpc.handler._operation_handler.SyncOperationHandler

Start the operation, completing either synchronously or asynchronously.

Returns the result synchronously, or returns an operation token. Which path is taken may be decided at operation handling time.