Add originalRoute like originalUrl

[danieljuhl]

In a request we can get the originalUrl, which is the complete URL for the request after it has travelled through nested routes.

But I think an originalRoute would be at least as usefull, especially for request logging.

I don't think it should be that difficult to add.

Currently I've made a simple hack to accomplish this, but I rather see it built-in.

var _ = require('lodash');
var express = require('express');
var Router = express.Router;
var Router_process_params = Router.process_params;

Router.process_params = function (layer, called, req, res, done) {
  req.originalRoute = (req.originalRoute || '') + (req.route && req.route.path || layer.path || '');
  return Router_process_params.apply(this, _.toArray(arguments));
}

[dougwilson]

Can you show a little express app that makes use of this as well, please :)?

[danieljuhl]

@dougwilson Is the following good enough?

A request could be GET /api/user/123, and I would expect to be able to get the full route /api/user/:id in the request object.

server.js

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

app.use('/api', require('./api').router);

app.listen(port);

api/index.js

var express = require('express');
var router = express.Router();

router.use('/user', require('./user'));
router.use('/items', require('./items'));

exports.router = router;

api/user.js

var express = require('express');
var router = express.Router();

router.get('/:id', function(...) {});
router.get('/', function(...) {});

exports.router = router;

api/items.js

var express = require('express');
var router = express.Router();

router.get('/:id', function(...) {});
router.get('/', function(...) {});

exports.router = router;

[dougwilson]

How would it work for RegExp routes or array routes?

[dougwilson]

i.e. we need it to work if your main file has

app.use(['/api', '/api/v1'], require('./api').router);

or

app.use(/^\/api(?:\/v1)?\//i, require('./api').router);

[danieljuhl]

@dougwilson I see your concerns, and that we have to re-think it, to ensure all methods will be handled correctly.

Another approach could be to simply expose an array of routes in the order they were matched, and if you are going to use the data, you'll have to deal with the different data types.

Assume that you'd replaced my route in server.js with one of you version, then req.originalRoute === [['/api', '/api/v1'], '/user', '/:id']; or req.originalRoute === [/^\/api(?:\/v1)?\//i, '/user', '/:id']. In the "array" version, we might actually be able to identify which of the two was used for the request, and then show that specific one instead of an array - and then we only need to see if we can do something better on RegExp-route.

I don't know if newrelic is able to handle all cases (haven't investigated their code further), but they do something similar to my hacky workaround. https://github.com/newrelic/node-newrelic/blob/master/lib/instrumentation/express.js#L184

[dougwilson]

That's fine. I don't mind adding something for this. We just want to make sure that what gets added to Express core is compatible with all of Express's features, rather than only the features a particular user just happens to be using it is all :)

[danieljuhl]

I'm all in on that - I did not just want this to be a feature for me :) This issue was to rise a discussion on a good way to implement something like this, as the new Router in Express 4 is giving the power to split and nest routes, but the downside is, that it can be hard to know exactly where you are, and for logging purpose it is often useful to be able to group by route rather than exact URL, to know how many request of a specific type has happend.

Which way do you prefer? Some way to concat the routes or should we go with the array of routes a particular request has travelled from entry to the final route?

[dougwilson]

An array that gets built up sounds like the simplest method to me.

[danieljuhl]

An array is fine with me... if a use case needs another format, it simply has to handle the transformation from the array to something else, eg a concat-string.

[devlato]

Hey, I can confirm that it would be great to have originalRoute. I'm trying to implement declarative ACL based on routing so it's very uncomfortable to deal with it without knowing what route was matched =(

[dougwilson]

Any traction on a PR?