How to access req and res objects in hooks?

Riyadh Zenasni

I would like to ask whether it is possible to access the req and the res objects provided by express .

Essentially I would like to check the http request headers each time before executing a hook.

Thanks in advance.

PitaJ

For what hook?

Riyadh Zenasni

@PitaJ I would say any hook. Is there a way to do so?

PitaJ

You might be able to use continuation-local storage to do this. If you added a middleware like so:

var cls = require('cls-hooked');

var express = cls.createNamespace('express');

app.use(function (req, res, next) {
  express.set('request', req);
  express.set('response', res);

  express.run(next);
});

then you could probably use those later like this:

plugin.addStyleSheet = function (data, next) {
  var req = express.get('request');
  // do something with request
  
  next(null, data);
};

Beware, I haven't tested any of this. What I wrote may not work at all. It's worth a try. I general, though, I'd recommend using the data you have in the hook itself. There's usually a better way.

Riyadh Zenasni

Interesting. I never knew that such a thing existed (storing at the chain level). I'll post again when I give it a try.

Doing it through the data provided at the hook level is very difficult, because the different hooks (userCreate, ...etc) are executed away from the middleware scope.

Thanks.

julian

Yes... adding in continuation local storage is something we really wanted to do, although when @akhoury tried to do it a couple years back, the technology was as-yet still a little immature.

Perhaps it is time for us to take a look at it again