priem
v2.0.0-alpha.12
Published
React Hook to declaratively subscribe to external data resources.
Downloads
12
Maintainers
vlad-zhukovReadme
priem · 
React Hook to declaratively subscribe to external data resources.
Table of Contents
Installation
yarn add priemGetting 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
fn: (AsyncFunction): An async function that takes arguments fromuseResourceand must return a Promise. If promise rejects, the cache item corresponding to these arguments will have a rejected status.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
args(Record<string, unknown> | undefined): An array of arguments that will be passed to a function increateResource. Can also beundefinedwhich 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:
data(any): The last successful data. Defaults toundefined.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.