Ruby + Tk command binding - scope issue?

Question

So I have this app

require \'tk\'
class Foo
  def my_fancy_function
    puts \"hello, world!\"
  end

  def initialize
    @root = TkRoot.new{title \"Hello,          


        

Answer 1

Usually, passing blocks to Tk constructors is unnecessary. The resulting scope is confusing, so I think it should be discouraged.

Examples of same which contain only literal values are inflexible, and teach a bad habit.

Here, a minimal change to your program makes it work, while maintaining readability:

require 'tk'
class Foo
  def my_fancy_function
    puts "hello, world!"
  end

  def initialize
    @root = TkRoot.new{title "Hello, world!"}
    frame = TkFrame.new
    my_fancy_button = begin
      b = TkButton.new frame
      b.text "Press meee"
      b.command {my_fancy_function}
      b.pack
    end
    frame.pack
    Tk.mainloop
  end
end

bar = Foo.new

It works for me using Ruby 2.2.5 (with Tk 8.5.12) on Windows 7.