Q:

Ruby Sinatra NoMethodError

I've tried running this with Ruby 1.9.3 as well as 2.0, but nothing seemed to work. Here's the code:
require 'sinatra'

before do
   set :display_string, 'Welcome from Ruby!'
end
get '/' do
   settings.display_string
end

The error is:
NoMethodError at /
undefined method `set' for (sinatra application code here)

This code:
set :display_string, 'Welcome from Ruby!'

seems to cause the issue. I'm running Thin 1.5.1 , latest version of Sinatra 1.4.3
EDIT: It seems that this works well if set is not inside the "before do/end" block. So it's something about the set being in the before do/end block.

A:

I think you should set your configure with configure block:
before do
  configure do
    set :display_string, 'Welcome from Ruby!'
  end
end

see more sinatra docs about the configure

