Does perspective-python support multi-pane workspace with chart plugins?

[Turdot]

Question

I'm using perspective-python (v4.0.1) and trying to create a multi-pane dashboard with charts (Y Line, Y Bar, Y Area) using perspective-workspace.

What works:

• ✅ PerspectiveWidget in JupyterLab with single charts (Y Bar, Y Line, etc.)
• ✅ perspective-workspace with Datagrid plugin via Python Tornado server + HTML

What doesn't work:

• ❌ perspective-workspace with chart plugins (Y Line, Y Bar, Y Area) - throws error:

Error: Cannot read properties of null (reading 'opacity')
TypeError: Cannot read properties of null (reading 'opacity')
    at colorStyles.ts:63:26
    at mc (colorStyles.ts:42:26)
    at pc.update (plugin.ts:481:9)
    at async pc.draw (plugin.ts:312:9)

My setup:

• Python server (Tornado) serving data via WebSocket
• HTML page loading from CDN (@finos/perspective-* or @perspective-dev/*)
• Both CDN sources produce the same error

Code example:

server.py

import perspective
import perspective.handlers.tornado

server = perspective.Server()
client = server.new_local_client()
table = client.table(data, name="pnl")

app = tornado.web.Application([
    (r"/websocket", perspective.handlers.tornado.PerspectiveTornadoHandler,
     {"perspective_server": server}),
])

index.html

<perspective-workspace id="workspace"></perspective-workspace>
<script type="module">
    import perspective from "https://cdn.jsdelivr.net/npm/@finos/perspective/dist/cdn/perspective.js";
    // ... other imports

    const client = await perspective.websocket("ws://localhost:8083/websocket");
    const table = await client.open_table("pnl");
    
    workspace.tables.set("pnl", table);
    workspace.restore({
        viewers: {
            "chart": {
                plugin: "Y Line",  // Error occurs here
                group_by: ["Date"],
                columns: ["Value"],
                table: "pnl"
            }
        }
    });
</script>

Questions:

1. Is multi-pane workspace with chart plugins supported when using Python backend?
2. Is this a known CSS/theme compatibility issue between Python server and JS frontend?
3. Are there plans to provide a native Python widget for multi-pane workspace (like PerspectiveWorkspaceWidget)?

Environment:

• perspective-python: 4.0.1
• Python: 3.12
• OS: macOS
• Browser: Chrome

Thanks!