app.mountpath is not set correctly when used within the app itself

[thomasfr]

Hi,

I have to use app.mountpath in the views of my app, as a prefix for some urls. In this example i used it for the url to a css file which is in a public directory in the app (/app/public), but it could also be used for dynamically creating links depending on the mountpath.

What i did is basically this:

// /index.js

var app = express()
var mountpoint = "/foo";
app.use(mountpoint, require("./app/index.js"))

// /app/index.js

var app = module.exports = express()

app.locals.baseurl = app.mountpath.replace(/\/$/, "") // <-- of course, this is set to '/' at this moment, because it is not yet mounted under 'mountpoint' (/foo)

var router = express.Router()
var route = router.route("/bar")
route.get(function(request, response, next) {
  response.render("bar")
});

app.use(router)

// /app/views/bar.jade
doctype html
html(lang="en")
  head
    meta(charset="utf-8")
    link(href="#{baseurl}/css/style.css", rel="stylesheet")

When requesting /foo/bar the link href should be /foo/css/style.css but it is /css/style.css

Maybe i am using it in a way it was not intended. If so, please tell me how i can achieve the same result.

Thanks
cheers
Thomas

[defunctzombie]

As you noted, mountpath is not yet set because the app is not yet mounted.
In your specific example you have two options, both involve using middleware to set the local.

Option 1: Use middleware in the child app to set the local (in app/index.js)

app.use(function(req, res) {
    res.locals.baseurl = app.mountpath;
});

mountpath will be set by the time a request arrives because the app was mounted already.

The alternative is to use middleware outside of the app to do the same thing (in index.js)

app.use(function(req, res) {
   res.locals.baseurl = mountpath;
});
app.use(mountpath, require('./app'));

[thomasfr]

I see.
Thanks for the quick reply!
cheers