JSPM – use-asset@0.2.0

Package Exports

use-asset

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (use-asset) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

Each asset you create comes with its own cache. When you request something from it, the arguments that you pass will act as cache-keys. If you request later on using the same keys, it won't have to re-fetch but serves the result that it already knows.

import React, { Suspense } from "react"
import { createAsset } from "use-asset"

const asset = createAsset(async (id, version) => {
  const res = await fetch(`https://hacker-news.firebaseio.com/${version}/item/${id}.json`)
  return await res.json()
})

function Post({ id }) {
  const { by, title } = asset.read(id, "v0")
  return <div>{title} by {by}</div>
}

function App() {
  <Suspense fallback={null}>
    <Post id={10000} />
  </Suspense>
}

Preloading assets

// You can preload assets, these will be executed and cached immediately
asset.preload("/image.png")

Cache busting strategies

// This asset will be removed from the cache in 15 seconds
const asset = createAsset(promiseFn, 15000)
// Clear all cached entries
asset.clear()
// Clear a specific entry
asset.clear("/image.png")

Peeking into entries outside of suspense

// This will either return the value (without suspense!) or undefined
asset.peek("/image.png")

You can also use the useAsset hook, which is modelled after react-promise-suspense. This makes it possible to define assets on the spot instead of having to define them externally. They use a global cache, anything you request at any time is written into it.

import { useAsset } from "use-asset"

function Post({ id }) {
  const { by, title } = useAsset(fn, [id])
  return <div>{title} by {by}</div>
}

function App() {
  <Suspense fallback={null}>
    <Post id={1000} />

Cache busting, preload and peeking

The hook has the same API as any asset:

// Bust cache in 15 seconds
useAsset.lifespan = 15000
useAsset(promiseFn, ["/image.png"])
// Clear all cached entries
useAsset.clear()
// Clear a specific entry
useAsset.clear("/image.png")
// Preload entries
useAsset.preload(promiseFn, "/image.png")
// This will either return the value (without suspense!) or undefined
useAsset.peek("/image.png")

Simple data fetching

Fetching posts from hacker-news: codesandbox

Infinite load on scroll

Fetching HN posts infinitely: codesandbox

Async dependencies

Component A waits for the result of component B: codesandbox