Set default content_type for Sinatra

Question

In Sinatra is it possible to make content_type 'application/json' the default? Because I'm building a REST API.

Adam Lassek · Answer 1 · 2011-01-11T00:17:22.510

77

Sure, add content_type to the before callback:

class MyApp < Sinatra::Base

  before do
    content_type 'application/json'
  end

  ...

end

Sinatra 1.1 introduces pattern-matching before filters:

before '/admin/*' do
  check_logged_in
end

edited Jan 11 '11 at 00:17

answered Jan 08 '11 at 03:14

Adam Lassek

Thanks! How do I create a context so that the before filter is only applied to a specific group of routes and not all? – ma11hew28 Jan 08 '11 at 03:18
@MattDiPasquale This should do the trick: http://blog.alastairdawson.com/2010/07/27/a-sinatra-before-only-filter/ – Adam Lassek Jan 08 '11 at 03:20
@MattDePasqaule you can also override the content type within individual routes. – Adam Lassek Jan 08 '11 at 23:52
1

sinatra 1.1 supports pattern before filter, so the patch is not necessary. – Konstantin Haase Jan 10 '11 at 16:37
@Konstantin thanks for the heads up, much better than my suggestion. – Adam Lassek Jan 11 '11 at 00:17
@Adam Lassek, thanks for all your help! @Konstantin, pretty sweet. Thanks! Oh yeah, I see [before filters with pattern matching](http://www.sinatrarb.com/intro#Filters) on the README now. I must've missed that. Thanks. – ma11hew28 Jan 12 '11 at 20:48

Pere Joan Martorell · Accepted Answer · 2021-09-29T14:49:51.510

6

For a JSON API the most recommendable way to set a default Content-Type for all your responses is to add the following in your Sinatra class:

set :default_content_type, :json

It will include a Content-Type: application/json header in all your responses.

edited Sep 29 '21 at 14:49

answered Mar 27 '21 at 10:37

2 Answers2