I am using/testing HTMX v4.0.0-beta6 right now, and I have the following test file (runnable via uv):
#! /usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.14"
# dependencies = [
# "sse-starlette~=3.0",
# "starlette~=1.0",
# "uvicorn[standard]~=0.51.0",
# ]
# ///
import asyncio
import collections.abc
import sse_starlette
import starlette.applications
import starlette.requests
import starlette.responses
import starlette.routing
import uvicorn
CONTENT = """
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<script src="https://cdn.jsdelivr.net/npm/htmx.org@4.0.0-beta6/dist/htmx.min.js" defer></script>
<script src="https://cdn.jsdelivr.net/npm/htmx.org@4.0.0-beta6/dist/ext/hx-sse.min.js" defer></script>
<title>HTMX SSE Playground</title>
</head>
<body>
<output aria-live="polite" hx-sse:connect="/sse" hx-sse:close="done"></output>
</body>
</html>
"""
async def homepage(_: starlette.requests.Request) -> starlette.responses.HTMLResponse:
return starlette.responses.HTMLResponse(content=CONTENT)
async def sse_endpoint(
_: starlette.requests.Request,
) -> sse_starlette.EventSourceResponse:
async def values() -> collections.abc.AsyncIterable[sse_starlette.ServerSentEvent]:
for idx in range(10):
yield sse_starlette.ServerSentEvent(data=f"data {idx}")
await asyncio.sleep(1)
# if data=None, `hx-sse:close` does not work
# yield sse_starlette.ServerSentEvent(event="done")
yield sse_starlette.ServerSentEvent(event="done", data="")
return sse_starlette.EventSourceResponse(content=values())
app = starlette.applications.Starlette(
routes=[
starlette.routing.Route("/sse", sse_endpoint, methods=["GET"]),
starlette.routing.Route("/", homepage, methods=["GET"]),
]
)
if __name__ == "__main__":
uvicorn.run(app, host="127.0.0.1", port=8080)Currently, hx-sse:close does not close the long-running hx-sse:connect session when an event done is received with no data. Is this expected behavior? For it to work properly, I need to send an empty string.
I am using/testing HTMX
v4.0.0-beta6right now, and I have the following test file (runnable viauv):Currently,
hx-sse:closedoes not close the long-runninghx-sse:connectsession when an eventdoneis received with no data. Is this expected behavior? For it to work properly, I need to send an empty string.