CODEWITHSUNDEEP
javascriptnode.jsexpress
Abilio Marques
Abilio Marques

Reputation: 161

Get access to Express mountpath from inside a module

In an attempt to build a truly modular express app (one that can run stand alone or as a part of another app) I need to find out the cleanest way to find the mount path from inside the subapp. For a short example, lets say that there are two files: main.js and subapp.js

main.js

var express = require('express');
var app = express();
var localApp = express();
var subapp = require('./subapp');

app.use('/foo', subapp);
app.use('/bar', localApp);
console.log(localApp.mountpath); // yes, this prints '/bar' as expected
...

subapp.js

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

var truePath = app.mountpath; // I wish this would point to '/foo', but instead points to '/'

...
module.exports = app;

What is the best way (as in cleanest) to find the mountpath from inside the module? I'm doing this trying to solve this problem: Access to mountpath variable from inside a template using express in a non hardwired way.

As shown in the example, tried already with app.mountpath without success

Upvotes: 1

Views: 337

Answers (3)

Nocturno
Nocturno

Reputation: 10027

Try req.baseUrl:

app.js

var express = require('express');
var app = express();
var foo = require('./foo');

app.use('/foo', foo);

app.listen(3000);

foo.js

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

router.get('/', function(req, res) {
  console.log(req.baseUrl); // '/foo'
  res.send('foo');
});

module.exports = router;

Upvotes: 0

Abilio Marques
Abilio Marques

Reputation: 161

As answered by alsotang, this is actually a problem of execution sequence, but it can be solved in what I think is a clean way. There is an event that is fired after the module is mounted, so you can do:

var truePath = = "/";

app.on('mount', function (parent) {
  truePath = app.mountpath;
});

Where in real life truePath could be app.locals.truePath, so it can be accessed from inside the views.

Upvotes: 2

alsotang
alsotang

Reputation: 1605

eh..It's a problem of execution sequence.

In your subapp.js, the app.mountpath statement is before module.exports = app.

But only you export the app, then the app be mounted, then it would be set the mountpath property.

so, you should retrieve mountpath after the app be mounted by outer express.

My suggestion are two:

  1. set the mountpath in your subapp.js. And outer express read this property.
  2. perhaps you think 1 is not truly modular. so you can alternatively define a config file. and both main.js and subapp.js read mountpath from the config.

Upvotes: 0

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