Expressjs + handlebars formatting date

Question

i've got this object

{ title: 'A TITLE',
  description: 'Lorem Ipsum...',
  _id: 50806930bbf612a858000013,
  __v: 0,
  screenings: 
   [ { venue: 'Venue1', dates: [Object] },
     { venue: 'Venue2', dates: [Object] } ] }

coming out of my mongoDB.

dates is a list of dates (dah!).

My issue is now I want to have them formatted with momentjs server-side.

It would look like I should be using mustache lambdas, but it appears impossible using my stack (expressjs, consolidate, handlebars...)

Anybody solved this?

Here's what I'm trying now

Theatre.find({"screenings.dates":{$gte:lastSunday, $lte:nextSunday}}, function(err, entities){
    res.render('index', {
        entities: entities,
        giveitatry: function(a) {
            return moment(a).format("MMM Do YY")
        }
    });
});

and on my template I have:

{{#entities}}
<div class="span3">{{#giveitatry}} {{dates.0.}} {{/giveitatry}}</div>
{{/entities}}

Here's part of the expressjs conf

var moment = require('moment');

var express = require('express')
  , cons = require('consolidate')
  , name = 'mustache';

app.configure(function(){
 app.set('view engine', 'hjs');
 app.engine('.hjs', cons.mustache);
 ...

yes, extension's still hjs 'cause i started using hogan but i wasn't able to do it with hogan so i moved to consolidate+mustache.

i'm using node v0.8.8 and expressjs 3.0.0rc4

Answer 1

If you use mustache.js lambdas, you need to return a function instead. The parameters for this function are text, which contains textual representation of the template content and render that can be explicitly invoked to render the template.

The best solution I have found so far is that you first use the default renderer, then pass the resulting date string back to a constructor of new Date object, which then is further passed to moment function. Finally you just return the date with desirated formatting.

Full code:

giveitatry: function() {
    return function(text, render) {
        var date = moment(new Date(render(text)));
        return date.format("MMMM Do YY");
    }
}

Works similarly well for lists of dates:

{{#entities}}
  {{#dates}}
    <div class="span3">{{#giveitatry}}{{.}}{{/giveitatry}}</div>
  {{/dates}}
{{/entities}}

You are not alone in this problem. The introduction for helpers / filters that would provide a cleaner solution to this problem is ongoing in mustache.js's issue tracker (see [1], [2]).