Streaming

Table of Contents

1. Server-to-Client Streaming
   1. Example Callbacks
2. Client-to-Server Streaming
   1. Full Client Streaming Example
3. Notes

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Server-to-Client Streaming

Use hub_connection.stream() to subscribe to a server-side streaming method. The subscription object accepts three callbacks:

Callback	Description
next	Called for each item streamed from the server
complete	Called when the stream ends successfully
error	Called if the stream encounters an error

hub_connection.stream(
    "Counter",
    [len(self.items), 500]  # method arguments
).subscribe({
    "next": self.on_next,
    "complete": self.on_complete,
    "error": self.on_error
})

Example Callbacks

def on_next(self, value):
    print(f"Received: {value}")

def on_complete(self):
    print("Stream complete")

def on_error(self, error):
    print(f"Stream error: {error}")

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Client-to-Server Streaming

Use a Subject to stream data from the client to the server:

from signalrcore.subject import Subject

subject = Subject()

# Start the streaming invocation
hub_connection.send("UploadStream", subject)

# Send items during the stream
subject.next(str(iteration))

# Signal end of stream
subject.complete()

Full Client Streaming Example

from signalrcore.subject import Subject
import time

subject = Subject()
hub_connection.send("UploadStream", subject)

for i in range(10):
    subject.next(str(i))
    time.sleep(0.5)

subject.complete()

---

Notes

• Server-to-client streaming uses the IAsyncEnumerable<T> or ChannelReader<T> pattern on the .NET server side.
• Client-to-server streaming sends items incrementally until subject.complete() is called.
• More examples are available in the tests folder.