CODEWITHSUNDEEP
javascriptnode.jssyntax
Mr Ed
Mr Ed

Reputation: 11

node.js/JavaScript syntax - add extra parameter to passed parameters

I'm building a REST API using node.js/Express.

I have some middleware applied to certain routes. I have a JavaScript syntax error which I can't resolve.

server.js

const express = require('express')
const router = express.Router()


const watchdogController = {
  ping: function(req, res, next) {
    console.log('watchdog')
    res.status(200).send('woof!')
    //next()
  }
}
const middleware = function(req, res, next) {
  console.log('middleware')
  next()
}
const middleware2 = function(req, res, next, roles) {
  console.log('middleware2')
  //console.log(roles)   //I want to be able to view the roles here!
  next()
}


//This line is where I have the issue...
router.get('/watchdog', middleware, middleware2, watchdogController.ping)



module.exports = router

I need to be able to pass an array of roles to middleware2. E.g.

router.get('/watchdog', middleware, middleware2(...['ordinary','supervisor']), watchdogController.ping)

But this syntax fails :(

node server.js results in:

middleware2
undefined
/Users/asdf7/Desktop/asdf7/lib/router.js:19
  next()
  ^

TypeError: next is not a function
    at middleware2 (/Users/asdf7/Desktop/eoh/lib/router.js:19:3)
    at Object.<anonymous> (/Users/asdf7/Desktop/eoh/lib/router.js:26:37)
    at Module._compile (internal/modules/cjs/loader.js:701:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:712:10)
    at Module.load (internal/modules/cjs/loader.js:600:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:539:12)
    at Function.Module._load (internal/modules/cjs/loader.js:531:3)
    at Module.require (internal/modules/cjs/loader.js:637:17)
    at require (internal/modules/cjs/helpers.js:22:18)
    at Object.<anonymous> (/Users/asdf7/Desktop/asdf7/index.js:2:16)

This works:

router.get('/watchdog', middleware, middleware2, watchdogController.ping)

But now I can't see any roles in middleware2 ;( I need to be able to view the roles array in the middleware2 function.

I can't figure out what syntax to use... Can you guys help?

Upvotes: 0

Views: 95

Answers (1)

Mr Ed
Mr Ed

Reputation: 11

Solution (with thanks to @DaveNewton):

const express = require('express')
const router = express.Router()


const watchdogController = {
  ping: function(req, res, next) {
    console.log('watchdog')
    res.status(200).send('woof!')
    //next()
  }
}
const middleware = function(req, res, next) {
  console.log('middleware')
  next()
}
const middleware2 = roles => function(req, res, next) {
  console.log('middleware2')
  console.log(roles)
  next()
}

router.get('/watchdog', middleware, middleware2(['ordinary','supervisor']), watchdogController.ping)



module.exports = router

Upvotes: 1

Related Questions