Capitalizing titles

//Methods to modify the string in place. I chose to use a different regex selector because using "\b" breaks on apostrophes and leave you with words like "You'Re" instead of "You're"...

class String

def titlecase()
ignore_list = %w{of etc and by the for on is at to but nor or a via}
capitalize_all_ex(ignore_list)
end

def titlecase!()
ignore_list = %w{of etc and by the for on is at to but nor or a via}
capitalize_all_ex!(ignore_list)
end

def capitalize_all(force_downcase = true)
ignore_list = %w{}
capitalize_all_ex(ignore_list, force_downcase)
end

def capitalize_all!(force_downcase = true)
ignore_list = %w{}
capitalize_all_ex!(ignore_list, force_downcase)
end

def capitalize_all_ex(ignore_list, force_downcase = true)
# if force_downcase is true then the
# string is, um, downcased first :-)
if force_downcase
self.downcase.gsub(/[\w\']+/){ |w|
ignore_list.include?(w) ? w : w.capitalize
}
else
self.gsub(/[\w\']+/){ |w|
ignore_list.include?(w) ? w : w.capitalize
}
end
end

def capitalize_all_ex!(ignore_list, force_downcase = true)
if force_downcase
self.replace(self.downcase.gsub(/[\w\']+/){ |w|
ignore_list.include?(w) ? w : w.capitalize
})
else
self.replace(self.gsub(/[\w\']+/){ |w|
ignore_list.include?(w) ? w : w.capitalize
})
end
end
end