From: Robert Klemme <bob.news@...>
Date: 2006-01-06T01:37:59+09:00
Subject: Re: Trapping errors, a simple example

John Maclean wrote:
> Hey Chaps,
> 
> Here's a really simple menu with only 4 options. I'd like to be able
> do some simple error trapping... How's it done? 
> 
> #!/usr/bin/ruby
> #Wed Jan  4 06:17:22 GMT 2006
> class TopMenu
>   def welcome
>     puts "Welcome to de-blah-de-blah-de-blah"
>     puts "~~~~~~~ ~~ ~~ ~~~~ ~~ ~~~~ ~~ ~~~~~"
>   end
> 
>   def options
>     # we will use this data to create a class called Option
>     # each option will have a new menu
>     # and will be a child class of the main one
>     print "------------------------------------\nmenu - Which stage
>   are you at?\n------------------------------------\n0:- Before site
> work\n1:- During site work\n2:- After site work\n3:- Other stuff\nq:-
> quit!\n" end  
> 
>   # grab the input
>   def topchoice
>     print "enter your choice (0,1,2,q) : "
>     p =  $stdin.gets # TODO:- check it's validity # TODO:- is the

p.chomp!

if /\a[012q]\Z/ 
  # ok
  case p
    when 0
    when 1
....
  end
else
  # error
end

HTH

    robert

>     choice a number in the correct range?  # TODO:- does he wanna
>     quit? print "you have chosen #{p}" if p == "0"
>       print "you have chosen #{p}"
>     else
>       if p == "q"
>       print "you have chosen #{p}"
>     end
>   end
> end
> 
> 
> 
> 
> # create a new instance
> top = TopMenu.new
> top.welcome
> top.options
> top.topchoice