Centarius
If AfterJS and RogueJS had a baby...
NextJS beloved grandchild..
Getting started with Centarius
Centarius has same API as After.js.
If you have familiarize yourself with After, then you are not finding it difficult to migrate to Centarius.
Also : You can build it on your SSR boilerplate (either it webpack, parcel, etc).
Centarius is just another component wrapper to ease React SSR.
Quickstart with Razzle
curl https://codeload.github.com/rayandrews/centarius/tar.gz/master | tar -xz --strip=2 centarius-master/examples/basic
cd basic
Background
After is awesome library but it has some drawbacks that I found it difficult to modify it in my other projects such as,
- Not able to modify routes tree
- Not able to modify static method for get initial props (getInitialProps is good, but you should be able to modify the name based on your content)
- Not able to add loading or error component while transitioning and getting initial props for other route
- Code splitting and load inital props based on routes config
How about Rogue?
Brilliant Idea to walk into react tree component recursively like Apollo did in their library
But.. something is bothering me..
- Document feature in Next and After is REALLY syntactic sugar
- GetInitialProps method only called on top highest level component (for performance, I know)
- And of course, not be able to modify static method too
tl;dr
I found them not too suitable for my works
Table of Contents
How Centarius Works
Centarius will walk through your React Tree to find static method that you've already specified.
If Centarius not found any static method, Centarius will gracefully return your rendered component.
Data Fetching
For now, in all components that you want to fetch, you can add a static async getInitialProps
or another function's name that exactly does the same
.
This will be called on both initial server render, and then client mounts.
Results are made available on the CONTEXT NOT ON PROPS
If you want to get data in the props, you must include the centariusHoc to easily passing data from context to props.
OR
Use CentariusConsumer (React ^16) to consume the data.
import React from 'react';
import { NavLink } from 'react-router-dom';
class Home extends React.Component {
static async getInitialProps({ req, res, match }) {
const stuff = await CallMyApi();
return { stuff };
}
render() {
return (
<div>
<NavLink to="/about">About</NavLink>
<h1>Home</h1>
</div>
);
}
}
export default Home;
getInitialProps | { name } : (ctx) => object
Within getInitialProps
or another function name
, you will get access to all you need to fetch data on both
the client and the server (same like After)
req?: Request
: (server-only) A Express.js request objectres?: Request
: (server-only) An Express.js response objectmatch
: React Router 4's match
object.history
: React Router 4's history
object.location
: (client-only) React Router 4's location
object.isServer
: Check whether code is running on server or client
You can also add another variable to be passed into static method like Redux Store, etc.
If you are using some server only modules inside getInitialProps
or anoher function name
, make sure to import them properly.
Otherwise, it'll slow down your app.
Taken from Next
Injected Context Data
data: any
- Whatever you have returned in getInitialProps
or another function name
loading: boolean
- Loading state while fetching data in clienterror: boolean
- Error state (but not throwing error) while fetching data in clientprefetch: (pathname: string) => void
- Imperatively prefetch and cache data for a path.
import React from 'react';
import { NavLink } from 'react-router-dom';
import { CentariusConsumer } from 'centarius/core';
class Home extends React.Component {
static async getInitialProps({ req, res, match }) {
const stuff = await CallMyApi();
return { stuff };
}
render() {
return (
<div>
<NavLink to="/about">About</NavLink>
<h1>Home</h1>
<CentariusConsumer>
{({ data, loading }) => (
if(loading) return <div>'Loading...'</div>;
return data.stuff;
)}
</CentariusConsumer>
</div>
);
}
}
export default Home;
OR
Using centariusHoc
to wrap your context into props, just like Redux connect
.
You can also pass options like LoadingComponent
and ErrorComponent
to reduce boilerplate in your render function.
centariusHoc : ({ LoadingComponent?: null, ErrorComponent?: null }) => (Component) => WrappedComponent
TL;DR All static methods will be hoisted
import React from 'react';
import { NavLink } from 'react-router-dom';
import centariusStateHoc from '@centarius/state-hoc'
class Home extends React.Component {
static async getInitialProps({ req, res, match }) {
const stuff = await CallMyApi();
return { stuff };
}
render() {
return (
<div>
<NavLink to="/about">About</NavLink>
<h1>Home</h1>
<div>{this.props.data.stuff}</div>
</div>
);
}
}
export default centariusHoc({
LoadingComponent: () => <div>Loading...</div>,
ErrorComponent: () => <div>Error!</div>
})(Home);
Routing
React Router 4 is used in all over Centarius API.
Custom Options
Examples
Centarius does not need any router config, so just passing React component with React Router 4 in it, and you're done!
Centarius has default options as follows
{
document = DefaultCentariusDocument,
staticMethod = 'getInitialProps',
rootId = 'root',
dataId = 'server-app-state',
}
If you want to change static method, rootId, and dataId, you must pass it both in client and server
Example
Centarius : ({ component, data, options }) => RenderedComponent
import React from 'react';
import { hydrate } from 'react-dom';
import { BrowserRouter } from 'react-router-dom';
import './client.css';
import { Centarius } from 'centarius/core';
import { getSsrData } from 'centarius/client';
import App from './App';
const data = getSsrData();
const options = {
staticMethod: 'fetchData',
}
hydrate(
<BrowserRouter>
<Centarius component={App} data={data} options={options} />
</BrowserRouter>,
document.getElementById('root')
);
if (module.hot) {
module.hot.accept();
}
render : (component = App, routerContext, options) => html : string
import express from 'express';
import { render } from 'centarius/server';
import App from './App';
const assets = require(process.env.RAZZLE_ASSETS_MANIFEST);
const server = express();
server
.disable('x-powered-by')
.use(express.static(process.env.RAZZLE_PUBLIC_DIR))
.get('/*', async (req, res) => {
const routerContext = {};
if (req.url.match(/.map$/)) return;
try {
const html = await render(App, routerContext, {
req,
res,
assets,
staticMethod: 'fetchData',
customThing: 'thing',
});
res.send(html);
} catch (error) {
res.json(error);
}
});
export default server;
Code Splitting
Examples
Centarius does not defining any code splitting method like After, Next, or Rogue (with loadable-components) did.
But Centarius does enforce you to implement code splitting with other libraries
With the right custom render function, you can implement it with another React code splitting library out there such as
Custom Document
Examples
Centarius works like After and Next, you can override any html structure that suitable for your needs.
Why we need it?
It really helps if you want to add CSS or other component with side-effects (React Helmet, etc) that needs custom document structure.
Example with React Native Web
import React, { Component } from 'react';
import { AppRegistry } from 'react-native';
import { renderToStaticMarkup } from 'react-dom/server';
import { CentariusRoot, CentariusData } from 'centarius/document';
export default class CustomDocument extends Component {
static async getInitialProps({ assets, data, renderPage }) {
const page = await renderPage();
AppRegistry.registerComponent('CentariusRoot', () => CentariusRoot);
const { getStyleElement } = AppRegistry.getApplication('CentariusRoot', {});
const rnwCss = renderToStaticMarkup(getStyleElement());
return { assets, data, rnwCss, ...page };
}
render() {
const {
rootId,
dataId,
helmet,
assets,
data,
rnwCss,
} = this.props;
const htmlAttrs = helmet.htmlAttributes.toComponent();
const bodyAttrs = helmet.bodyAttributes.toComponent();
return (
<html lang="en" {...htmlAttrs}>
<head>
<meta httpEquiv="X-UA-Compatible" content="IE=edge" />
<meta charSet="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
{helmet.title.toComponent()}
{helmet.meta.toComponent()}
{helmet.link.toComponent()}
{assets.client.css && (
<link rel="stylesheet" href={assets.client.css} />
)}
<style
id="react-native-stylesheet"
dangerouslySetInnerHTML={{
__html: rnwCss
.replace(/<\/style>/g, '')
.replace(/<style id="react-native-stylesheet">/g, ''),
}}
/>
</head>
<body {...bodyAttrs}>
<CentariusRoot id={rootId} />
<CentariusData id={dataId} data={data} />
<script
type="text/javascript"
src={assets.client.js}
crossOrigin="anonymous"
/>
</body>
</html>
);
}
}
If you were using something like styled-components
, and you need to wrap you entire app with some sort of additional provider or function, you can do this with renderPage()
.
Taken from After
import React, { Component } from 'react';
import { ServerStyleSheet } from 'styled-components'
import { renderToStaticMarkup } from 'react-dom/server';
import { CentariusRoot, CentariusData } from 'centarius/document';
export default class CustomDocument extends Component {
static async getInitialProps({ assets, data, renderPage }) {
const sheet = new ServerStyleSheet();
const page = await renderPage(App => props => sheet.collectStyles(<App {...props} />));
const styleTags = sheet.getStyleElement();
return { assets, data, ...page, styleTags };
}
render() {
const {
rootId,
dataId,
helmet,
assets,
data,
styleTags,
} = this.props;
const htmlAttrs = helmet.htmlAttributes.toComponent();
const bodyAttrs = helmet.bodyAttributes.toComponent();
return (
<html lang="en" {...htmlAttrs}>
<head>
<meta httpEquiv="X-UA-Compatible" content="IE=edge" />
<meta charSet="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
{helmet.title.toComponent()}
{helmet.meta.toComponent()}
{helmet.link.toComponent()}
{styleTags}
</head>
<body {...bodyAttrs}>
<CentariusRoot id={rootId} />
<CentariusData id={dataId} data={data} />
<script
type="text/javascript"
src={assets.client.js}
defer
crossOrigin="anonymous"
/>
</body>
</html>
);
}
To use custom document, you need to pass it on server file
import express from 'express';
import { render } from 'centarius/server';
import App from './App';
import Doc from './Document';
const assets = require(process.env.RAZZLE_ASSETS_MANIFEST);
const server = express();
server
.disable('x-powered-by')
.use(express.static(process.env.RAZZLE_PUBLIC_DIR))
.get('/*', async (req, res) => {
const routerContext = {};
if (req.url.match(/.map$/)) return;
try {
const html = await render(App, routerContext, {
req,
res,
assets,
staticMethod: 'fetchData',
customThing: 'thing',
document: Doc,
});
res.send(html);
} catch (error) {
res.json(error);
}
});
export default server;
Custom/Async Rendering
Examples
You can provide a custom (potentially async) rendering function as an option to Centarius render
function, just like After.js.
If it presents, it will be used instead of the default ReactDOMServer renderToString function.
It has to return an object of shape { html : string!, ...otherProps }
, in which html
will be used as the rendered string.
otherProps
will be passed as props to the rendered Document.
defaultRenderer = (node) => ({ html: ReactDOMServer.renderToString(node) })
Example
import express from 'express';
import { render } from 'centarius/server';
import { Capture } from 'react-loadable';
import { getBundles } from 'react-loadable/webpack';
import stats from 'build/react-loadable.json';
import configureStore from 'store/configureStore';
import App from './App';
import Doc from './Document';
const assets = require(process.env.RAZZLE_ASSETS_MANIFEST);
const server = express();
server
.disable('x-powered-by')
.use(express.static(process.env.RAZZLE_PUBLIC_DIR))
.get('/*', async (req, res) => {
const routerContext = {};
if (req.url.match(/.map$/)) return;
try {
const preloadedState = {};
const store = configureStore(preloadedState);
const modules = [];
const customRenderer = (node) => {
const CustomApp = (
<Capture report={(moduleName) => modules.push(moduleName)}>
<Provider store={store}>{node}</Provider>
</Capture>
);
const bundles = getBundles(stats, modules);
const chunks = bundles.filter((bundle) => bundle.file.endsWith('.js'));
return {
chunks,
store,
html: renderToString(CustomApp),
};
};
const html = await render(App, routerContext, {
req,
res,
assets,
staticMethod: 'fetchData',
customThing: 'thing',
document: Doc,
store,
});
res.send(html);
} catch (error) {
res.json(error);
}
});
export default server;
Authors
Special Thanks
Inspirations
License
This project is licensed under the MIT License - see the LICENSE.md file for details