StreamRequest

public protocol StreamRequest : NetworkRequest

A request for a steram is similar to a Request, only that it does not send an HTTP request, but asks for a web socket. Instead of a Response that yields at most one value, it therefore returns a Stream which allows for receiving arbitrarily many values as well as sending values. Apart from that, working with a stream request is very similar to working with an HTTP request. It is also scheduled against an API represented by an HttpService. However, the service’s retriers as well as its headers are ignored. Still, the Service.process(_:) method is called.

Types

  • Defines the type of the values sent by the client to the peer. By default, this is set to Void, indicating unidirectional communication from the peer to the client.

    Declaration

    Swift

    associatedtype Message = Void

  • Defines the type of the values sent from the peer to the client.

    Declaration

    Swift

    associatedtype Result

Encoding Data for Sending

  • Encodes a message sent from the client to the peer into an appropriate format for WebSocket communication. There exist default implementations for the case where Message is of type Void, Data, or String. In the first case, an error is thrown (as Void indicates unidirectional communication from the peer to the client). In the latter two cases, the returned value can be synthesized trivially.

    Declaration

    Swift

    func encode(_ message: Message) throws -> URLSessionWebSocketTask.Message

    Parameters

    message

    The message to be sent from the client to the peer.

Decoding Data for Receiving

  • Decodes a message sent by the peer into the stream’s result type. There exist default implementations for result types Void, Data and String. In the former case, a Void value is returned no matter the message, in the latter two cases, the return value can be synthesized easily.

    Declaration

    Swift

    func decode(_ message: URLSessionWebSocketTask.Message) throws -> Result

    Parameters

    message

    The message sent by the peer.

Establishing Streams

  • schedule(with:) Extension method

    Schedules the stream request against the API specified by the given HTTP service. The returned value is the stream over which messages can be sent (bidirectionally). Note that this method is very similar to Request.schedule(with:).

    Declaration

    Swift

    public func schedule<S>(with service: S) -> Stream<Self, S> where S : HttpService

    Parameters

    service

    The service representing the API against which to schedule this request.