spaday-perspective

Perspective for spaday

Overview

spaday-perspective moves the existing PerspectivePanel integration out of spaday core. Its self-contained <perspective-panel> bundle includes Perspective's client, viewer, workspace, datagrid, themes, and viewer WASM.

Interactive example

This complete app serves a live Perspective table. Add trade streams a new row into the grid, the select switches between flat and grouped layouts, and the checkbox changes the viewer theme.

import perspective
from perspective.handlers.starlette import PerspectiveStarletteHandler
from starlette.responses import JSONResponse
from starlette.routing import Route, WebSocketRoute
from starlette.websockets import WebSocket

from spaday import CallEndpoint, cond, element, eq, field, obj
from spaday.backends.starlette import serve
from spaday_perspective import PerspectivePanel

server = perspective.Server()
client = server.new_local_client()
trades = client.table(
    [
        {"id": 1, "symbol": "AAPL", "side": "buy", "price": 211.10},
        {"id": 2, "symbol": "MSFT", "side": "sell", "price": 503.02},
    ],
    name="trades",
)
next_id = 2


async def add_trade(_request):
    global next_id
    next_id += 1
    trades.update(
        [
            {
                "id": next_id,
                "symbol": "AAPL" if next_id % 2 else "MSFT",
                "side": "buy" if next_id % 2 else "sell",
                "price": 210 + next_id,
            }
        ]
    )
    return JSONResponse({"id": next_id})


async def perspective_socket(websocket: WebSocket):
    await PerspectiveStarletteHandler(perspective_server=server, websocket=websocket).run()


def layout(*, grouped=False):
    viewer = {"table": "trades", "plugin": "Datagrid", "columns": ["symbol", "side", "price"]}
    if grouped:
        viewer.update({"group_by": ["symbol"], "columns": ["price"], "aggregates": {"price": "avg"}})
    return {
        "sizes": [1],
        "detail": {"main": {"type": "tab-area", "widgets": ["trades"], "currentIndex": 0}},
        "master": {"sizes": [], "widgets": []},
        "mode": "globalFilters",
        "viewers": {"trades": viewer},
    }


panel = (
    PerspectivePanel()
    .compute("theme", cond(field("dark"), "dark", "light"))
    .compute(
        "config",
        obj(
            {
                "ws_url": "/perspective",
                "tables": ["trades"],
                "layout": cond(eq(field("view"), "grouped"), layout(grouped=True), layout()),
            }
        ),
    )
    .style(display="block", height="70vh", margin_top="1rem")
)

view = element("select").bind("value", "view", mode="two-way").child(
    element("option", "Blotter", value="blotter"),
    element("option", "Average by symbol", value="grouped"),
)
dark = element("input", type="checkbox").bind("checked", "dark", mode="two-way")
page = (
    element("main")
    .style(margin="1rem", font_family="system-ui")
    .child(element("button").text("Add trade").on("click", CallEndpoint("POST", "/api/trades")))
    .child(view)
    .child(element("label").child(dark, " Dark theme"))
    .child(panel)
)

app = serve(
    page,
    packages=["perspective"],
    store={"view": "blotter", "dark": False},
    routes=[
        Route("/api/trades", add_trade, methods=["POST"]),
        WebSocketRoute("/perspective", perspective_socket),
    ],
)

Save this as app.py, then run pip install spaday-perspective perspective-python starlette uvicorn and uvicorn app:app. Open http://127.0.0.1:8000.

This keeps Perspective's bulk data on its native websocket. A spaday/transports model only needs to carry the small serializable connection/layout config. Replacing config reconnects when ws_url changes and restores changed layouts; theme accepts light, dark, or a Perspective theme name.

Installing this project registers the perspective entry point with spaday. The equivalent explicit forms are packages=[spaday_perspective.package] and packages=["spaday_perspective:package"].

[!NOTE] This library was generated using copier from the Base Python Project Template repository.