In Sinatra(Ruby), how should I create global variables which are assigned values only once in the application lifetime?

Question

In Sinatra, I\'m unable to create global variables which are assigned values only once in the application lifetime. Am I missing something? My simplified code looks like thi

Answer 1

I ran into a similar issue, I was trying to initialize an instance variable @a using the initialize method but kept receiving an exception every time:

class MyApp < Sinatra::Application

    def initialize
        @a = 1
    end

    get '/' do
        puts @a
        'inside get'
    end
end

I finally decided to look into the Sinatra code for initialize:

# File 'lib/sinatra/base.rb', line 877

def initialize(app = nil)
  super()
  @app = app
  @template_cache = Tilt::Cache.new
  yield self if block_given?
end

Looks like it does some necessary bootstrapping and I needed to call super().

    def initialize
        super()
        @a = 1
    end

This seemed to fix my issue and everything worked as expected.