Using dynamicHelpers in routes setup with Express and node.js

Question

Using dynamicHelpers in routes setup with Express and node.js

I began using node.js+express combo very recently and I stumbled at a need to use dynamicHelpers not only in my views but also inside my routes setup (routes/index.js in default express config). Should I use some different pattern?

app.js

app.dynamicHelpers({
    translate : function(req, res) {
        return translate;
    },
    language : function(req, res) {
        return req.session.language || "en";
    },
});

Below I would like to have a convenient access to whatever I set for my dynamicHelpers because in my mind it is the same context .. so why set it up two times?

var routes = {};
routes.index = function(req, res) {
    res.render('index', {
        title : 'My webpage',
        categories : categoryPositions,
        referrer : req.header("Referrer"),
        languages : ["pl", "en", "de"],
        <----- here I would like to use my dynamicHelpers (for example translate)
    })
};

I know I can pass my data in many ways but I do not want to repeat my code and want to set up the common context only once and as cleanly as polssible. I welcome any criticism and good advice!

node.js
express

Answer 1

functions.js

module.exports = {
  translate : function(req, res) {
    return translate;
  },
  language : function(req, res) {
    return req.session.language || "en";
  },
};

helpers.js

var functions = require('./functions');

app.dynamicHelpers({
  translate : functions.translate,
  language : functions.language
});

Depending on what you need you can also write the helpers like this

var functions = require('./functions');

app.dynamicHelpers( functions );

routes.js

var functions = require('./functions');

var routes = {
  index: function(req, res) {
    res.render('index', {
      title : 'My webpage',
      categories : categoryPositions,
      referrer : req.header("Referrer"),
      languages : ["pl", "en", "de"],
      stuff: functions.translate(req, res) // <----- here I would like to use my dynamicHelpers (for example translate)
    })
  }
};

Answer 2

So actually the solution is to use not yet released express 3.0, modify:

npm install -g express@3.0

Follow https://github.com/visionmedia/express/wiki/Migrating-from-2.x-to-3.x , http://www.devthought.com/code/use-jade-blocks-not-layouts/

The new express simplified dynamicHelpers to the use of res.locals which are both available in the routes setup and then bound to the view.

Example:

// app.
app.locals.use(function(req, res) {
    var language = req.session.language || "en";
    res.locals.language = language;
    res.locals.translate = function(clause) {
        return translate(clause, language);
    };
});

In the routes setup I can now access both res.locals.language and res.locals.translate. In my views I simply can use translate('something').