Dynamic path in express routes

Question

I wonder how to using path in express dynamically. For example, i'm using lodash for finding a path in different file with regex method.

routes.js

const json = require('./routes.json')
const _ = require('lodash')
routes.use(function(req, res, next) {

  let str = req.path
  let path = str.split('/')[1]

  // [Request] => /test/123
  console.log(path)
  // [Result] => test

  let test = _.find(json.routes, function(item) {
    return item.path.match(new RegExp('^/' + path + '*'))
  })
  console.log(test)
  //{"path" : "/test/:id", "target" : "localhost:2018", "message" : "This is Test Response" },

  routes.get(test.path, function(req, res) {
    res.json("Done")
  })
})

On above code, i just nested the routes. But there's nothing any response. Is there any ways to do this? This method also i want to use with DB if necessary. Thanks anyway

Answer 1

Using middleware is impossible. When a request comes, expressjs will search a registered path first. So here we go why that code not running as well.

For example, I'm as an user request : localhost:2018/test/123

Please following my comment in below

const json = require('./routes.json')
const _ = require('lodash')
routes.use(function(req, res, next) {

  let str = req.path
  let path = str.split('/')[1]

  // [Request] => /test/123
  console.log(path)
  // [Result] => test

  let test = _.find(json.routes, function(item) {
    return item.path.match(new RegExp('^/' + path + '*'))
  })
  console.log(test)
  //{"path" : "/test/:id", "target" : "localhost:2018", "message" : "This is Test Response" },

  //And now, the routes has been registered by /test/:id.
  //But, you never get response because you was hitting the first request and you need a second request for see if that works. But you can't do a second request, this method will reseting again. Correctmeifimwrong

  routes.get(test.path, function(req, res) {
    res.json("Done")
  })
})

How to approach this goal then? However, we need a registering our routes inside app.use or routes.use . So far what i got, we can using loop in here.

//Now, we registering our path into routes.use
_.find(json.routes, function(item) {
  routes.use(item.path, function(req, res) {
    res.json("Done")
  })
})

//The result become

/** 
* routes.use('/test:id/', function(req, res, next){
    res.json("Done")
})

routes.use('/hi/', function(req, res, next){
    res.json("Done")
})

*/

Reference : Building a service API Part 4

Thanks anyway, leave me a comment if there's something wrong with this method :D