#320 Jbuilder

Jan 30, 2012 | 8 minutes | Plugins

Jbuilder provides a DSL for generating JSON. It includes a template engine which allows you to create complex responses with helpers and conditions.

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Wil Gieseler almost 13 years ago

Is it possible to do fragment caching with Jbuilder?

Ryan Bates almost 13 years ago

Good question. You can't use the cache helper method because that is designed to work with ERB. However you can use the read_fragment and write_fragment methods to manage the cache directly.

Stefan Wrobel over 12 years ago

Can you give a little more detail on this?

jonathan-mui about 10 years ago

Late reply, but...

There's json.cache!, but I couldn't get that to work. I ended up doing a Rails.cache.fetch([id, 'name']) do ... end block around the entire json response in the jbuilder file.

Andrey Voronkov almost 13 years ago

Is there any gem for generating xml representation in such kind of way?

Semyon Perepelitsa almost 13 years ago

There is XML Builder that comes bundled with Rails ("builder" gem)

Jim Li almost 13 years ago

check out a gem called "representative_view" https://github.com/mdub/representative_view

Benjamin Roth almost 13 years ago

Check acts_as_api, really useful and modular. You'll define templates once for json and xml.

Semyon Perepelitsa almost 13 years ago

I have used ActiveModel::Serializers::JSON module to make a serializer/presenter class and I like this approach better than Jbuilder.

Milovan Zogovic almost 13 years ago

Andy L almost 13 years ago

Is jBuilder similar to RABL? (I think it is...) If so - what are the pros/cons of jBuilder vs RABL?

Damien Brz. almost 13 years ago

Yes it is but RABL offers you JSON and XML.

Personally, I preferred RABL. I guess its up to everyone.

Gavin Morrice almost 13 years ago

I just discovered RABL - me gusta!

Ryan Bates almost 13 years ago

RABL is similar, and I will likely do an episode on it in the future since it is different enough from Jbuilder. What I like about Jbuilder is its simplicity (it is just two small files). But RABL has more to offer in its interface.

rackom almost 13 years ago

RABL crashes for me on rails 3.2.1 on ruby 1.9.2

/Users/rackom/.rvm/gems/ruby-1.9.2-p290/gems/rabl-0.2.8/lib/rabl/template.rb:66:in <top (required)>: uninitialized constant ActionView::TemplateHandlers (NameError)

jbuilder on same configuration throws this error
Illegal instruction: 4

Any help?

Yale Spector over 12 years ago

see #157

rackom over 12 years ago

Yeah, thanks a lot but:
I can fix it, so RABL would be in handler list, BUT in rails 3.2.2 it seems to me that it is trying to render json while requesting for html. #180

Stephen Paul Suarez over 12 years ago

from the last time i've seen it, RABL is good with objects that are ActiveModel compliant. doesn't provide a lot of support if for example you have an Array/Hash object that you got from redis that needs to be represented as json.

Forrest Zeisler almost 13 years ago

The show notes have 'views/articles/show.json.builder' as the one path, but it should be '.jbuilder'

Very timely episode. I'm implementing it now!

Žiga almost 13 years ago

Thanks! I was going nuts because of this :)

Andrew Gertig almost 13 years ago

I was hoping you would do a railscast on Jbuilder! How about one on Grape, it's got some pretty cool features. If you wanted to do a 5min Pro on Grape I'd be ok with that :)

Markus Mühlberger over 12 years ago

+1. An episode on Grape would be awesome.

Barak Cohen almost 13 years ago

Is there a way to do API versioning and inheritance with jbuilder?

Wojtek Kruszewski almost 12 years ago

I second this question. RABL has "extend" https://github.com/nesquena/rabl/wiki/Reusing-templates

jamesw almost 13 years ago

How do you reference a boolean field?
If the value of a boolean field is false then the field will not be included in the json response

Nils Haldenwang over 12 years ago

Good question, I am currently having the same problem.

Stephen Paul Suarez over 12 years ago

for a quick&dirty support on jsonp with this, you can go with an after_filter:

          ruby
        
after_filter do |controller| 
    if controller.params[:callback] && controller.params[:format].to_s == 'json'
      controller.response['Content-Type'] = 'application/javascript'
      controller.response.body = "%s(%s)" % [controller.params[:callback], controller.response.body]
    end
  end

Brandon Williams over 12 years ago

Can Jbuilder templates be used inside of layouts? I tried creating a layout:

          ruby
        
json.results do |json|
  yield
end

But unfortunately I just get {"results":{}}.

Mike Mondragon over 12 years ago

anyone know how to make jbuilder pretty print?

Nayef Copty over 11 years ago

Any luck with this?

jfine over 11 years ago

Not perfect but this kinda works.

http://stackoverflow.com/questions/13128485/pretty-print-json-generated-with-a-jbuilder-template-in-rails-3-2-8

This looks like an option as well.

http://stackoverflow.com/questions/86653/how-can-i-pretty-format-my-json-output-in-ruby-on-rails/13029297#13029297

Mark Ericksen about 10 years ago

This is late, but a tip for others...

Assuming the reason is for viewing it yourself in a browser, the easiest (and general fix) is to use a nice browser plugin. There are two plugins both named "JSONView" for Chrome and Firefox. I use the Chrome one. Very nice tool for viewing JSON API responses.

Kevin Whitaker over 12 years ago

I'm having trouble using Jbuilder with Rails 3.1.0, specifically my Jbuilder view (index.json.builder) is rendering empty, and throwing no errors. I've placed the issue on Stack hoping to get some help:

http://stackoverflow.com/questions/9999395/rails-3-1-jbuilder-rendering-empty-views

Has anyone else seen this behavior?

Alexis Rabago Carvajal over 10 years ago

i had some problems but it was because i was trying to render a file/object not an attribute, something like:

json.id @image.id
json.name @image.name
json.address @image.image

(using carrierwave)

then even tho it was ok and not rising any error it didnt know how to render a file object, I had to do:

json.address @image.image.route

neetiraj over 12 years ago

+1 for a episode on Grape

Evgeniy.S.Semenchuk over 12 years ago

Goog question from Brandon Williams. Can Jbuilder templates be used inside of layouts?

Maximum that I have been to achieve is this:

          ruby
        
# v1.json.jbuilder - layout
json.request do |json|
  json.url "https://api.storyful.com/stories.json"
  json.status 200
end
json.data JSON.parse(yield)

# show.json.jbuilder - action view
json.test 'test form show'

Don Hill over 11 years ago

What a name I thought this screen cast was going to be about Borland JBuilder(late 90's editor) ;)