Cycle-Express

Express.js driver for cycle.js

This is a experimental driver that allows you to have express router requests as stream, and use it in cycle.js apps.

API

streams of requests

API of router object is very similar to express.Router

router.METHOD(path) // -> stream of requests

router.get('/api/users')
  .filter(req => req.user)
  ...

nested streams of requests

Method route internally will create new express.Router and use (attach) it on current Router instance that will supply you with kind of isolated stream of request from the path.

let nestedRouter = router.route(path) // --> nested router attached on `path`
nestedRouter.METHOD(path) // -> stream of requests

You can use this to pass such nested router to function:

RouteUser({router: router.route('/api/user'), db, log})

streams of responses

Each incoming request from stream has unique id, you should put this id into to sink stream, so driver could make find a corresponding response (usually referred as res) object. So, such object passed to router sink steam:

{
  id: '123',
  status: 202,
  send: {a: 1, b: 2}
}

will set response status to 202 and send (calling send method on express's res object) {a: 1, b: 2}

Example

import {run} from '@cycle/core'
import {Observable as O} from 'rx'
import {makeRouterDriver} from 'cycle-express'
import {Router} from 'express'
 
const router = Router()
 
const Main = ({router, cb}) => {
  return {
    router: db.map(result => ({
      id: result.query.id, // send back to router object that contains original request id 
      send: result.data
    ))
    db: router.map((req) => ({
      req: req.id, // mark db query with original request id 
      id: req.params.id // this is just "db query API" for the sake of simplicity
    }))
  }
}
 
run(Main, {
  router: makeRouterDriver(router),
  db: simpleFlatDbDriver
})