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paypal / react-engine

a composite render engine for universal (isomorphic) express apps to render both plain react views and react-router views
Apache License 2.0
1.45k stars 130 forks source link

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react-engine

Build Status

What is react-engine?

Install

# In your express app, react-engine needs to be installed alongside react/react-dom (react-router is optional)
$ npm install react-engine react react-dom react-router --save

Usage On Server Side

Setup in an Express app
var Express = require('express');
var ReactEngine = require('react-engine');

var app = Express();

// create an engine instance
var engine = ReactEngine.server.create({
  /*
    see the complete server options spec here:
    https://github.com/paypal/react-engine#server-options-spec
  */
});

// set the engine
app.engine('.jsx', engine);

// set the view directory
app.set('views', __dirname + '/views');

// set jsx or js as the view engine
// (without this you would need to supply the extension to res.render())
// ex: res.render('index.jsx') instead of just res.render('index').
app.set('view engine', 'jsx');

// finally, set the custom view
app.set('view', require('react-engine/lib/expressView'));
Setup in a KrakenJS app's config.json
{
  "express": {
    "view engine": "jsx",
    "view": "require:react-engine/lib/expressView",
  },
  "view engines": {
    "jsx": {
      "module": "react-engine/lib/server",
      "renderer": {
        "method": "create",
        "arguments": [{
          /*
            see the complete server options spec here:
            https://github.com/paypal/react-engine#server-options-spec
          */
        }]
      }
    }
  }
}
Server options spec

Pass in a JavaScript object as options to the react-engine's server engine create method. The options object should contain the mandatory routes property with the route definition.

Additionally, it can contain the following optional properties,

Rendering views on server side
var data = {}; // your data model

// for a simple react view rendering
res.render(viewName, data);

// for react-router rendering
// pass in the `url` and react-engine
// will run the react-router behind the scenes.
res.render(req.url, data);

Usage On Client Side (Mounting)

// assuming we use a module bundler like `webpack` or `browserify`
var client = require('react-engine/lib/client');

// finally, boot whenever your app is ready
// example:
document.addEventListener('DOMContentLoaded', function onLoad() {

  // `onBoot` - Function (optional)
  // returns data that was used
  // during rendering as the first argument
  // the second argument is the `history` object that was created behind the scenes
  // (only available while using react-router)
  client.boot(/* client options object */, function onBoot(data, history) {

  });
};

// if the data is needed before booting on
// client, call `data` function anytime to get it.
// example:
var data = client.data();
Client options spec

Pass in a JavaScript object as options to the react-engine's client boot function. It can contain the following properties,

Data for component rendering

The actual data that gets fed into the component for rendering is the renderOptions object that express generates.

If you don't want to pass all that data, you can pass in an array of object keys or dot-lookup paths that react-engine can filter out from the renderOptions object before passing it into the component for rendering.

// example of using `renderOptionsKeysToFilter` to filter `renderOptions` keys
var engine = ReactEngine.server.create({
  renderOptionsKeysToFilter: [
    'mySensitiveData',
    'somearrayAtIndex[3].deeply.nested'
  ],
  routes: require(path.join(__dirname + './reactRoutes'))
});

Notes:

Handling redirects and route not found errors on the server side

While using react-router, it matches the url to a component based on the app's defined routes. react-engine captures the redirects and not-found cases that are encountered while trying to run the react-router's match function on the server side.

To handle the above during the lifecycle of a request, add an error type check in your express error middleware. The following are the three types of error that get thrown by react-engine:

Error Type Description
MATCH_REDIRECT** indicates that the url matched to a redirection
MATCH_NOT_FOUND indicates that the url did not match to any component
MATCH_INTERNAL_ERROR indicates that react-router encountered an internal error

_** for MATCHREDIRECT error, redirectLocation property of the err has the new redirection location

// example express error middleware
app.use(function(err, req, res, next) {
  console.error(err);

  // http://expressjs.com/en/guide/error-handling.html
  if (res.headersSent) {
    return next(err);
  }

  if (err._type && err._type === ReactEngine.reactRouterServerErrors.MATCH_REDIRECT) {
    return res.redirect(302, err.redirectLocation);
  }
  else if (err._type && err._type === ReactEngine.reactRouterServerErrors.MATCH_NOT_FOUND) {
    return res.status(404).send('Route Not Found!');
  }
  else {
    // for ReactEngine.reactRouterServerErrors.MATCH_INTERNAL_ERROR or
    // any other error we just send the error message back
    return res.status(500).send(err.message);
  }
});

Yeoman Generator

There is a Yeoman generator available to create a new express or KrakenJS application which uses react-engine: generator-react-engine.

Performance Profiling

Pass in a function to the performanceCollector property to collect the stats object for every render.

stats

The object that contains the stats info for each render by react-engine. It has the below properties.

// example
function collector(stats) {
  console.log(stats);
}

var engine = require('react-engine').server.create({
  routes: './routes.jsx'
  performanceCollector: collector
});

Notes

License

Apache Software License v2.0