Pre-routing with querystrings with Express in Node JS

Question

I\'m trying to use express to parse the querystring in case certain parameters are set and execute a little piece of code, before the actual routing is happening. The use-ca

Answer 1

Ok, there is quite a logical flaw in here. Routing only uses the URL, and ignores the querystring.

The (or better "A") solution is actually this:

app.get('*', function(req, res, next) {
  if (req.query.something) {
    console.log("Something: "+req.query.something);
  };
  next();
})

Explanation: As Express is ignoring the querystring for the routing, the only regular expression matching all URL's is "*". Once that is triggered, I can check if said querystring is existing, do my logic and continue the routing matching the next rule by using "next()".

And yes: facepalm

Answer 2

express does not allow you to route based on query strings. You could add some middleware which performs some operation if the relevant parameter is present;

app.use(function (req, res, next) {
    if (req.query.something) {
        // Do something; call next() when done.
    } else {
        next();
    }
});

app.get('/someroute', function (req, res, next) {
    // Assume your query params have been processed
});