ToJbuilder

gem 'to_jbuilder'

require 'json'
require 'to_jbuilder'

{
  content: "<p>This is <i>serious</i> monkey business</p>",
  created_at: "2011-10-29T20:45:28-05:00",
  updated_at: "2011-10-29T20:45:28-05:00",

  author: {
    name: "Yuki Nishijima",
    email_address: "'Yuki Nishijima' <mail@yukinishijima.net>",
    url: "http://www.yukinishijima.net"
  },

  visitors: 15,

  comments: [
    { content: "Hello everyone!", created_at: "2011-10-29T20:45:28-05:00" },
    { content: "To you my good sir!", created_at: "2011-10-29T20:47:28-05:00" }
  ],

  attachments: [
    { filename: "forecast.xls", url: "http://example.com/downloads/forecast.xls" },
    { filename: "presentation.pdf", url: "http://example.com/downloads/presentation.pdf" }
  ]
}.to_jbuilder(:message)

json.content    @message.content
json.created_at @message.created_at
json.updated_at @message.updated_at

json.author do
  json.name          @author.name
  json.email_address @author.email_address
  json.url           @author.url
end

json.visitors @message.visitors

json.comments @comments do |comment|
  json.content    comment.content
  json.created_at comment.created_at
end

json.attachments @attachments do |attachment|
  json.filename attachment.filename
  json.url      attachment.url
end