express-router

Express routing with priority settings.

Install

$ npm i --save @openovate/express-router

Usage

It is generally similar to express.Router.

const express = require('express');
const Router = require('@openovate/express-router');

const router = Router();

router.get('/some/path', (req, res) => {
  res.send('Hello World');
});

const app = express();
app.use(router);

app.listen(3000);

The basic route can be formed in several ways.

router.route('/').get((req, res) => {
  res.send('Hello World');
});

// ... or ...

router.get('/', (req, res) => {
  res.send('Hello World');
});

// ... both above actually calls ...

router.route('get', '/', (req, res) => {
  res.send('Hello World');
});

// ... and that actually calls ...

router.on('GET /', (req, res) => {
  res.send('Hello World');
});

Async/Await

You can use async callbacks now it will still properly order by when it was defined.

router.get('/some/path', async(req, res) => {
  await something();
});

router.get('/some/path', (req, res) => {
  res.send('Done');
});

Priority

You can specify higher priority routes (negative priorities work too).

router.get('/some/path', (req, res) => {
  console.log('Run After');
});

router.get('/some/path', (req, res) => {
  console.log('Run Before');
}, 100);

No next()

With async/await there is no need for next() anymore. To pass an error to the express handler, just throw it.

router.get('/some/path', (req, res) => {
  throw new Error('Something happened...');
});

app.use(function (err, req, res) {
  res.status(500).send(err.message);
});

RouteTo ...

Routes can now invoke other routes manually with routeTo()

router.get('/some/path', async (req, res) => {
  await router.routeTo('get', '/some/other', req, res);
});

router.route('/some/other').get((req, res) => {
  res.send('Some other route');
});

Introducing stage, rest and content

stage is a combination of the URL query, form post and URL path parameters. rest is different than res.json() where it gives other routes an opportunity to add on to the rest data before sending it out. stage and rest use Registry from the JSM library. For a quick study, see: @openovate/jsm#registry-usage

The rationale for content is the same as rest where it is different than res.write() and res.send() where it gives other routes an opportunity to add on to the content data before sending it out.

// -> GET /some/path?foo[bar][]=zoo
router.get('/some/path', async (req, res) => {
  if (!req.stage.has('foo', 'bar', 0)) {
    req.stage.set('foo', 'bar', 0, 'zoo');
  }

  const foo = req.stage.get('foo', 'bar', 0);

  res.rest
    .set('error', false)
    .set('results', foo);

  // ... or ...
  res.content.set(foo);
});

Events with Priorities too ...

Router extends EventEmitter from the JSM library. For a quick study, see: @openovate/jsm#eventemitter-usage

router.on('do something', (req, res) => {
  console.log('Run After');
});

router.on('do something', (req, res) => {
  console.log('Run Before');
}, 100);

router.on('something else', (req, res) => {
  const foo = req.stage.get('foo');
  res.rest.set('results', foo);
});

router.get('/some/path', async (req, res) => {
  await router.emit('do something', req, res);
  const results = await router.request('something else', { foo: 'bar' });
  res.send(results); //-> bar
});