README.md

fetch-unless-cached

Store fetch JSON responses in localStorage with expire timers! And fetch only if the timer has expired.

---

What is it really?

• A wrapper on top isomorphic-fetch for JSON responses
• When data is fetched, it's stored in localStorage with an expire timer
• When data is reqeusted, it checks in the storage and only fetches if needed, otherwise it resolves the cached data.
• Optionally, the api call can be made when the browser is idle and the timer is udpated.

Installation

npm i --save fetch-unless-cached

Usage

1. Use the inbuilt cached fetch which caches response for 600 minutes.

   import cachedFetch from "fetch-unless-cached";

2. Or create a custom cached fetch function with your own duration

import {createfetchUnlessCached} from "fetch-unless-cached"

/**
 * Create a custom fetch function which caches response for 300 minutes
 */
const cachedFetch = createfetchUnlessCached(300)

function fetchMyData(){
  /*
   * cachedFetch is just isomorphic-fetch but coupled with cache
   * Do not perform .then(res => res.json()) as this happens internally
   *
   */
  ...
  return cachedFetch('myapi.com').then(response => console.log(response))
}

Note: If you would like to fetch during an idle state you can set the second argument to true.

const cachedFetch = createfetchUnlessCached(300, true);

Credits

• isomorphic-fetch - Fetch api for node and browser
• lscache - localStorage caching with timers

Caveats

• Works only with JSON responses