Skip to content

vlad-zhukov/priem

Repository files navigation

priem · npm Build Status codecov bundlephobia

React Hook to declaratively subscribe to external data resources.

Table of Contents

Installation

yarn add priem

Getting Started

App.js

import React from 'react';
import {createResource} from 'priem';

const useReddit = createResource(
    () =>
        fetch('https://www.reddit.com/r/reactjs.json')
            .then(res => res.json())
            .then(res => res.data.children),
    {
        ssrKey: 'reddit-resource',
    },
);

export default () => {
    const [redditData, {pending}] = useReddit({});

    if (!redditData) {
        return pending ? <h2>Loading...</h2> : <h2>Empty.</h2>;
    }

    return (
        <div style={{opacity: pending ? 0.5 : 1}}>
            <ul>
                {redditData.map((post, i) => (
                    <li key={i}>{post.title}</li>
                ))}
            </ul>
        </div>
    );
};

server.js

import React from 'react';
import ReactDOM from 'react-dom/server';
import {getDataFromTree} from 'priem/server';
import {flushStore} from 'priem';
import App from './App';

app.get(async (req, res) => {
    await getDataFromTree(<App />);
    const content = ReactDOM.renderToString(<App />);

    // We suggest to use a specific library instead of JSON.stringify
    // for example `devalue` or `serialize-javascript`.
    const storeJson = JSON.stringify(flushStore()).replace(/</g, '\\u003c');

    res.send(`
        <!doctype html>
        ${ReactDOM.renderToStaticMarkup(<Html content={content} />)}
        <script id="preloaded-state">
            window.__PRIEM_STORE__ = ${storeJson};
        </script>
    `);
});

client.js

import React from 'react';
import ReactDOM from 'react-dom';
import {hydrateStore} from 'priem';

hydrateStore(JSON.parse(window.__PRIEM_STORE__));
delete window.__PRIEM_STORE__;

// Note that the import order is important here
const App = require('./App').default;

ReactDOM.hydrate(<App />, document.getElementById('root'));

Examples

Example apps can be found under the examples/ directory.

API

createResource

Creates a React Hook that fetches and caches data.

Arguments

  1. fn: (AsyncFunction): An async function that takes arguments from useResource and must return a Promise. If promise rejects, the cache item corresponding to these arguments will have a rejected status.
  2. options (Object): An options object, that can have the following properties:
    • maxAge (number?): A time in milliseconds after which cache items will expire and trigger a refresh.
    • maxSize (number?): A number of maximum cache entries in store. After exceeding this amount the most former used item will be removed and a refresh triggered. Defaults to 1.
    • refreshOnMount (Boolean?): Refreshes data on mounting. Default to false.
    • ssrKey (string?): A unique key that will be used to place this resource to the store. Required for server-side rendering.

Returns

useResource.

useResource

A React Hook for subscribing to resources.

Arguments

  1. args (Record<string, unknown> | null): An array of arguments that will be passed to a function in createResource. Can also be null which will prevent the update which can be utilized for waiting for other async tasks or user interactions to finish. Defaults to [].

Returns

The function returns a tuple with data and a meta object:

  1. data (any): The last successful data. Defaults to null.
  2. meta (Object): Meta properties of most recent promise.
    • pending (boolean).
    • rejected (boolean).
    • reason (Error?).
    • refresh (Function): a method to update the resource.

getDataFromTree(element)

An async function that walks the component tree and fetches data from resources that have ssrKey set. Returns a promise that either resolves with undefined or rejects on errors.


hydrateStore(initialStore)

A function to hydrate internal store with initial data from server.


flushStore()

A function that clears internal store and returns it. It's safe to serialize it and send to client.


About

Rich async state management.

Resources

License

Stars

Watchers

Forks

Packages

No packages published