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Cannot update element of SVG image through websocket #187

@claudiomattera

Description

@claudiomattera

Hello,

I am trying to update one element of an SVG image through a websocket, but I cannot seem to make it work.

If I try to update it through a click, everything works fine (with the "Slippery SVGs" caveat mentioned here).
If I try with a websocket, it does not work.

I attached a Python program that shows my attempt.
If you open http://localhost:8080/manual and click on the circle, both the circle and the text change color alternating between red and blue.
If you open http://localhost:8080/continuous, only the text alternates color once per second, but not the circle, and the console log shows an error "htmx:oobErrorNoTarget".

Can you see anything I do wrong?

htmx version 2.0.8, htmx-ex-ws version 2.0.4

from asyncio import sleep
from datetime import timedelta

from aiohttp import web


color = "blue"


def main():
    app = web.Application()
    app.add_routes([
        web.get('/manual', handle_manual),
        web.get('/continuous', handle_continuous),
        web.get('/update', handle_update),
        web.get('/ws', handle_websocket),
    ])
    web.run_app(app)


async def handle_manual(request):
    response = """<!DOCTYPE html><html><head>
    <script
      src="https://unpkg.com/htmx.org@2.0.8/dist/htmx.js"
      crossorigin="anonymous"
    ></script>
  </head>
  <body>
    <svg>
      <circle id="circle1" r="35" cx="50" cy="50" fill="red" hx-get="/update" />
    </svg>
    <div id="message" style="font-weight: bold; color: red;">
    RED
    </div>
  </body>
</html>
"""
    return web.Response(text=response, content_type="text/html")


async def handle_continuous(request):
    response = """<!DOCTYPE html><html><head>
    <script
      src="https://unpkg.com/htmx.org@2.0.8/dist/htmx.js"
      crossorigin="anonymous"
    ></script>
    <script
      src="https://unpkg.com/htmx-ext-ws@2.0.4"
      integrity="sha384-1RwI/nvUSrMRuNj7hX1+27J8XDdCoSLf0EjEyF69nacuWyiJYoQ/j39RT1mSnd2G"
      crossorigin="anonymous">
    </script>
  </head>
  <body hx-ext="ws">
    <svg>
      <circle id="circle1" r="35" cx="50" cy="50" fill="red" />
    </svg>
    <div id="message" style="font-weight: bold; color: red;">
    RED
    </div>
    <div ws-connect="/ws"></div>
  </body>
</html>
"""
    return web.Response(text=response, content_type="text/html")


async def handle_update(request):
    global color
    response = fragment(color)
    color = "red" if color == "blue" else "blue"
    return web.Response(text=response, content_type="text/html")


async def handle_websocket(request):
    ws = web.WebSocketResponse()
    await ws.prepare(request)

    ws_color = "blue"

    while True:
        await sleep(timedelta(seconds=1).total_seconds())

        response = fragment(ws_color)
        ws_color = "red" if ws_color == "blue" else "blue"
        await ws.send_str(response)

    return ws


def fragment(color):
    return f"""
<template><svg>
<circle hx-swap-oob="true" id="circle1" r="35" cx="50" cy="50" fill="{color}" hx-get="/update" />
</svg></template>

<div hx-swap-oob="true" id="message" style="font-weight: bold; color: {color};">
{color.upper()}
</div>"""



if __name__ == '__main__':
    main()

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