SSE responses are not supported in the function

I noticed that the Appwrite Python function uses Flask for its construction, so I attempted to send chunks with Flask’s SSE response. However, the Appwrite function responses do not support the use of return Response(event_stream(), mimetype="text/event-stream")

TL;DR

The issue is that the Appwrite Functions currently do not support server-sent events (SSE) and do not allow for chunked responses. Setting the MIME type to `text/event-stream` is not possible in the Appwrite server. The suggested solutions are to use the existing inbuilt functions provided by Appwrite or to try Flask's SSE response, but neither of these options work. Unfortunately, there is no known solution or timeline for when SSE support will be available in Appwrite Functions.

There are inbuilt function to return value. You can check the example from the official docs:

https://appwrite.io/docs/products/functions/development#response

TypeScript

def main(context):
    type = context.req.query['type']

    if type == 'empty':
        return context.res.empty()
    elif type =='json':
        return context.res.json({"type": "This is a JSON response"})
    elif type == 'redirect':
        return context.res.redirect("https://appwrite.io", 301)
    elif type == 'html':
        return context.res.send("<h1>This is an HTML response</h1>", 200, {
            "content-type": "text/html"
        })
    else:
        return context.res.send("This is a text response")

I was aware of that, but none of them support the SSE Response, which I require.

I tried the next function:```python import time

def main(context): context.log("Starting")

TypeScript

def event_stream():
    context.log("I am inside the Function")
    for i in range(0, 20):
        yield 'data: {"message": "Hello ' + "{}".format(i) + '"}\n\n'
        time.sleep(0.3)
    yield 'data: {"message": "World"}\n\n'
    yield 'data: {"message": "stop"}\n\n'
    yield 'data: {"message": "World"}\n\n'
    yield 'data: {"message": "World"}\n\n'
    yield 'data: {"message": "World"}\n\n'
# Response(event_stream(), mimetype="text/event-stream")
return context.res.send(event_stream(), 200, {"content-type": "text/event-stream"})

TypeScript

Its works but It send all yield message as one response only.

I believe this is happening because the Appwrite server doesn't support setting the MIME type to text/event-stream, which is necessary to enable server-sent events on both the client and server side.

???

Yes, this is correct. Appwrite Functions do not currently support chunked responses. My understanding is that this is on the wishlist, but I'm not aware of any open Issue for it, or of any specific milestone (unless this is part of the SSR milestone for 1.5? - would need someone from Core to clarify that).

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