How to define global error handler for JSON in Sinatra

Question

I would like to define an error block (or something) that would return all exceptions formatted in JSON somehow plus returning the standard http code (e.g. 404 for not found, 303 for auth errors etc).

Something like:

error do
  e = env['sinatra.error']
  json :result => 'error', :message => e.message
end

Thanks!

Answer 1

This should work:

require 'sinatra'
require 'json'

# This is needed for testing, otherwise the default
# error handler kicks in
set :environment, :production

error do
  content_type :json
  status 400 # or whatever

  e = env['sinatra.error']
  {:result => 'error', :message => e.message}.to_json
end

get '/' do
  raise 'hell'
end

Test it with curl to see that it works.