Vielzeug

Page Source with Courier ​

Problem ​

You need Courier middleware and transport errors while Sourcerer owns collection state and request succession.

Solution ​

Map the Courier response into PageResult and forward Sourcerer’s signal.

ts
import { createCourier } from '@vielzeug/courier';
import { createPageSource } from '@vielzeug/sourcerer';

type Issue = { id: number; title: string };
type IssueResponse = { data: Issue[]; total: number };
const courier = createCourier({ baseUrl: 'https://api.example.test' });
const source = createPageSource({
  load: async ({ page, pageSize, params: search, signal }) => {
    const result = await courier.get<IssueResponse>('/issues', { query: { page, pageSize, search }, signal });
    return { items: result.data, totalItems: result.total };
  },
  params: '',
});

try {
  await source.reload();
  console.log(source.state.items);
} finally {
  source.dispose();
  courier.dispose();
}

Pitfalls ​

  • Keep authentication, middleware, timeouts, and transport errors on Courier.
  • Pass the loader signal to Courier.
  • Use a dedicated query cache when reads must be shared by key.