TsSTAC is designed as a Sans-I/O style library for loading and managing SpatioTemporal Asset Catalogs.
There are many different ways to fetch data in Javascript, so to make the library the most useful, we shouldn't force any specific one on users. We can however provide a reference implementation, so that users don't have to provide their own.
By not tieing an IO method we can better accomidate different access patterns such as:
- Single File STAC
- Eager caching and re-hydration with React-Query
- Loading data from the filesystem for server side use
- Baking a catalog into an app to save preloading.
import STAC from "tsstac"
import fetcher from "tsstac/reference-fetch"
// Create a STAC store
// This will be in charge of loading data, and mapping from loaded URLs
// to STAC catalogs, collections, and items
const stac_store = STAC(fetch=fetcher)
// Here we're loading up the catalog for landsat from S3,
// but we are choosing to delay loading child links
// until later rather than walking the whole catalog on load
const landsat_catalog = await stac_store.get_catalog("https://landsat-stac.s3.amazonaws.com/catalog.json", walk=false)
// We can quickly view the structure of a catalog (or other STAC objects)
// by describing them
console.log(await landsat_catalog.describe(depth=2))