@labbsr0x/fetch-text-cache

Fetch Text Cache

This project goal is to provide a almost seamless way to cache requests.

TODO

• make fetch plugable
• make a persitable object

By-pass

All requests are done using fetch, if the requests returns an OK response, the body and headers are cached. If an exception is thrown, the last cached result are returned, as if it was a regular response, except with a cached attribute.

How to use it?

Using fetch-text-cache should be identical to use fetch, except for the import.

const cachedFetch = require('fetch-text-cache')(fetch);

cachedFetch('http://localhost:4343/').then(resp => {
    resp.text().then(text => {
        console.log(text);
    })
});

Providing custom persistence

fetch-text-cache enables the user to use a custom persistence layer. It must be provided an object with three methods: put, get and contains, where the key is the URL and the value is the an object in custom format, received through put method. All these methods should return a Promise.

const map = {};
const persistenceControl = {
    put:(k,v) => new Promise(resolve=>{
        map[k] = v;
        resolve();
    }),
    get:k => Promise.resolve(map[k]),
    contains:k => Promise.resolve(!!map[k])
}

const cachedFetch = require('fetch-text-cache')(fetch,{persistenceControl});

cachedFetch('http://localhost:4343/').then(resp => {
    resp.text().then(text => {
        console.log(text);
    })
});

Preferable Mode

The preferableMode is used to set which is the first option where fetch-text-cache will fetch the resuilt.

• PreferableMode.ONLINE (default) it tries to execute the request online if something wrong happens then it searches in cache.
• PreferableMode.CACHE: it searches first in cache, if it doesn't find, then tries to online fetch;

const cachedFetch = require('fetch-text-cache')(fetch,{
    preferableMode: libCacheableFetch.PreferableMode.CACHE
});

cachedFetch('http://localhost:4343/').then(resp => {
    resp.text().then(text => {
        console.log(text);
    })
});