From: Jonathan Gillette <jonathan@...>
Date: 2002-03-30T05:13:56+09:00
Subject: My sprintf methods and props for FXRuby

I've had a blast with Ruby over the past seven or so months and thought I'd pass on a bit of favorite code.  I always find myself laying out my strings with sprintf and found it handy to add sprintf methods to arrays, hashes, and the REXML::Element class.  I thought someone else might find this useful or might clue me in on some optimizations.

# The Array#sjoin is similar to Array#join in that it creates a string
# containing the elements in order, but sjoin allows a format string,
# so
#   ['talby','boiler','doolittle','pinback'].sjoin( "(%s)", "," )
#   => (talby),(boiler),(doolittle),(pinback)
class Array
    def sjoin( fmt, sep )
        collect { |x| Kernel::sprintf( fmt, x ) }.join( sep )
    end
end

# Hash#sprintf will take a format string, then keys for each value to be used
#   test_hash = { 'name' => 'joe', 'relationship' => 'mom' }
#   test_hash.sprintf( '%s is my %s', 'name', 'relationship' )
#   => 'joe is my mom'
class Hash
    def sprintf( *args )
        if args == []; return; end
        eval "return Kernel::sprintf( '" + args.shift + "', " + args.sjoin( "@elements[ '%s' ].text.strip()", ", " ) + " )"
    end
end

# Takes a format string then a list of XPath expressions
#   root.sprintf( "%s is my %s", "person/name", "person/relationship" )
require 'rexml/document'
include REXML
class Element
    def sprintf( *args )
        if args == []; return; end
        eval "return Kernel::sprintf( '" + args.shift + "', " + args.sjoin( "@elements[ '%s' ].text.strip()", ", " ) + " )"
    end
end

That last one is sort of weak with the Element#text.strip() part if text is nil.  I often check for the existence of the elements before using sprintf() anyway. 

Big props to the FXRuby team.  I've had such fun with the whole module.  I've been working on a debugger for web applications over UDP [http://www.javuh.com/psychoo/screens/buggoo-freebsd.jpg].  Adding tabs, tables, input controls is a breeze.  Can't wait for threads to work with FOX on Windows.  Nice work overall though.

-- 

Jonathan Gillette
iNetZ Media
(801) 415-2566