connect-reqcontext

Middleware for Connect which provides globally accessible request context with lifecycle hooks.

This middleware can only be used inside an active domain, use connect-domain.

var connectDomain = require('connect-domain');
var connectReqContext = require('connect-reqcontext');

...
app.use(connectDomain());
app.use(connectReqContext.requestContext(function() {
  // return context you want to attach to the request
  return {
    db: new pg.Client(...)
  }
}, function (context) {
  // this callback will be called when response is finished
  // if custom callback on error is provided (see below) then this callback
  // will only be called on successful circumstances
  context.db.query('commit');
  context.db.end();
});
...
// middleware below is optional if you want custom cleanup on error
app.use(connectReqContext.requestContextOnError(function(context) {
  context.db.query('rollback');
  context.db.end();
});
...

// in another file, maybe in models.js or something like this
// you can access db connection without having access to a request object
var connectReqContext = require('connect-reqcontext');

function getUserById(id, cb) {
  connectReqContext.get('db').query("select ...", cb);
}