Handling dynamic URLs and the HTML forms

The Express framework also supports dynamic URLs. Let's say we have a separate page for every user in our system. The address to those pages looks like the following code:

/user/45/profile

Here, 45 is the unique number of the user in our database. It's of course normal to use one route handler for this functionality. We can't really define different functions for every user. The problem can be solved by using the following syntax:

var getUser = function(req, res, next) {
  res.send("Show user with id = " + req.params.id);
}
app.get('/user/:id/profile', getUser);

The route is actually like a regular expression with variables inside. Later, that variable is accessible in the req.params object. We can have more than one variable. Here is a slightly more complex example:

var getUser = function(req, res, next) {
  var userId = req.params.id;
  var actionToPerform = req.params.action;
  res.send("User (" + userId...