Express App Param Pam Pam

Author

Created by Rafase282

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Express App: Param Pam Pam

This exercise is about using URL parameters. For example, if you have /message/526aa677a8ceb64569c9d4fb, then you should know how to extract that value which is an ID of the message.

Create an Express.js server that processes PUT /message/:id requests and produces a SHA-1 hash of the current date combined with the ID from the URL.

For instance, if the server receives

PUT /message/526aa677a8ceb64569c9d4fb

it will respond with a hash of the current date (as a string) and the ID.

The SHA-1 can be computed like this:

require('crypto')
  .createHash('sha1')
  .update(new Date().toDateString() + id)
  .digest('hex')

HINTS

Express.js apps can also be mounted to paths that contain a variable by prepending a : to the beginning of a variable name. For instance, in the following, app handles PUT requests in any subdirectory of /path/:

app.put('/path/:NAME', function(req, res){ /* ... */ });

The given variable is then stored in req.params. So, to extract parameters from within the request handlers, use:

req.params.NAME

BONUS

You can use req.param middleware to parse the URL parameter.

For example,

app.param('id', function (req, res, next, id) {
  req.id = id
  ...
  next()
})

app.get('/message/:id', function (req, res, next) {
  console.log(req.id)
  next()
})

My Solution

var express = require('express');
var app = express();

app.put('/message/:NAME', function(req, res) {
  var id = req.params.NAME;
  res.send(require('crypto')
    .createHash('sha1')
    .update(new Date().toDateString() + id)
    .digest('hex')
  );
});

app.listen(process.argv[2]);

Official Solution:

var express = require('express')
var app = express()

app.put('/message/:id', function(req, res) {
  var id = req.params.id
  var str = require('crypto')
    .createHash('sha1')
    .update(new Date().toDateString() + id)
    .digest('hex')
  res.send(str)
})

app.listen(process.argv[2])