How to use underscore in jade template

Question

I want to use underscore function in jade template, like this

p= _.keys(user)

Not for client javascript, for in redering.

Through I did require 'underscore' in app.js, did not get along well. Of course it work properly in app.js.

ReferenceError: xxxxxxx _ is not defined

this is template error message. any idea?

thanks

Answer 1

If you are using Express.js (presumably you would be since you're using Jade) you can add underscore as a view helper.

app.helpers({
    _: require("underscore")
});

UPDATE Using Express 3+, the above will no longer work, use app.locals instead:

app.locals._ = require("underscore");

Answer 2

In Express 3.x helpers were removed. Instead use middleware and res.locals

app.use(function(req, res, next){
  res.locals._ = require('underscore');
  next();
});