custom error handling in rails, allows to respond with json when exeptions are thrown in api controllers and with standard error handling in all other cases

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery


  # CUSTOM EXCEPTION HANDLING
  rescue_from Exception do |e|
    error(e)
  end

  def routing_error
    raise ActionController::RoutingError.new(params[:path])
  end
 
  protected
  
  def error(e)
    #render :template => "#{Rails::root}/public/404.html"
    if env["ORIGINAL_FULLPATH"] =~ /^\/api/
    error_info = {
      :error => "internal-server-error",
      :exception => "#{e.class.name} : #{e.message}",
    }
    error_info[:trace] = e.backtrace[0,10] if Rails.env.development?
    render :json => error_info.to_json, :status => 500
    else
      #render :text => "500 Internal Server Error", :status => 500 # You can render your own template here
      raise e
    end
  end

  # ...
  
end

routes.rb

MyApp::Application.routes.draw do

  # ...

  # Any other routes are handled here (as ActionDispatch prevents RoutingError from hitting ApplicationController::rescue_action).
  match "*path", :to => "application#routing_error", :via => :all
end