From: James Edward Gray II <james@...>
Date: 2006-01-06T01:43:14+09:00
Subject: Re: Trapping errors, a simple example

On Jan 5, 2006, at 10:37 AM, Robert Klemme wrote:

> 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

You might also want to take a look at HighLine[1], which can make  
this kind of user interaction easier.

1:  http://rubyforge.org/projects/highline/

James Edward Gray II