useResource()

function useResource(fetchShape: ReadShape, params: object | null):
  Denormalize<typeof fetchShape.schema>;

function useResource(...[fetchShape: ReadShape, params: object | null]):
  Denormalize<typeof fetchShape.schema>[];

function useResource<
  Params extends Readonly<object>,
  S extends Schema
>(fetchShape: ReadShape<S, Params>, params: Params | null): Denormalize<S>;

function useResource<
  Params extends Readonly<object>,
  S extends Schema
>(...[fetchShape: ReadShape<S, Params>, params: Params | null]): Denormalize<S>[];

Excellent for retrieving the data you need.

Cache policy is Stale-While-Revalidate by default but also configurable.

• Triggers fetch:
  • On first-render
    • or parameters change
    • or required entity is deleted
    • or imperative invalidation triggered
  • and When not in cache or result is considered stale
  • and When no identical requests are in flight
  • and when params are not null
• On Error (404, 500, etc):
  • Throws error to be caught by Error Boundaries
• While Loading:
  • Returns previously cached if exists (even if stale)
  • Suspend rendering otherwise

Single

function Post({ id }: { id: number }) {
  const post = useResource(PostResource.detailShape(), { id });
  // post as PostResource
}

List

function Posts() {
  const posts = useResource(PostResource.listShape(), {});
  // posts as PostResource[]
}

Parallel

function Posts() {
  const [user, posts] = useResource(
    [UserResource.detailShape(), { id: userId }],
    [PostResource.listShape(), { userId }],
  );
  // user as UserResource
  // posts as PostResource[]
}

Sequential

function PostWithAuthor() {
  const post = useResource(PostResource.detailShape(), { id });
  // post as PostResource
  const author = useResource(UserResource.detailShape(), {
    id: post.userId,
  });
  // author as UserResource
}

Paginated data

When entities are stored in nested structures, that structure will remain.

export class PaginatedPostResource extends Resource {
  readonly id: number | null = null;
  readonly title: string = '';
  readonly content: string = '';

  static urlRoot = 'http://test.com/post/';

  static listShape<T extends typeof Resource>(this: T) {
    return {
      ...super.listShape(),
      schema: { results: [this.asSchema()], nextPage: '', lastPage: '' },
    };
  }
}

function ArticleList({ page }: { page: string }) {
  const { results: posts, nextPage, lastPage } = useResource(
    PaginatedPostResource.listShape(),
    { page },
  );
  // posts as PaginatedPostResource[]
}

Useful FetchShapes to send

Resource provides these built-in:

• detailShape()
• listShape()

Feel free to add your own FetchShape as well.