Perspective

Loading data from a virtual Table

Loading a virtual (server-only) [Table] works just like loading a local/Web Worker [Table] - just pass the virtual [Table] to viewer.load(). In the browser:

const elem = document.getElementsByTagName("perspective-viewer")[0];

// Bind to the server's worker instead of instantiating a Web Worker.
const websocket = await perspective.websocket(
    window.location.origin.replace("http", "ws")
);

// Bind the viewer to the preloaded data source.  `table` and `view` objects
// live on the server.
const server_table = await websocket.open_table("table_one");
await elem.load(server_table);

Alternatively, data can be cloned from a server-side virtual Table into a client-side WebAssemblt Table. The browser clone will be synced via delta updates transferred via Apache Arrow IPC format, but local Views created will be calculated locally on the client browser.

const worker = await perspective.worker();
const server_view = await server_table.view();
const client_table = worker.table(server_view);
await elem.load(client_table);

<perspective-viewer> instances bound in this way are otherwise no different than <perspective-viewer>s which rely on a Web Worker, and can even share a host application with Web Worker-bound table()s. The same promise-based API is used to communicate with the server-instantiated view(), only in this case it is over a websocket.