DRY Documentation between method and OptionParser

Ruby
1

I suspect that lots of folks have run into this very problem:

I have a method. It has lots of options. I need a command line
program that will give users command line access to run the method. I
can use OptionParser to parse the command line options into a hash and
give this hash to my method, like this:

The method:

def my_method(arg1, arg2, *opts)
…
end

The command line interface:

opts = {}
parser = OptionParser.new do |op|
op.banner = “usage: progname.rb arg1 arg2 [OPTIONS]”
op.on(“-f”, “–first”, Float, “this is the first option”) {|v|
opts[:first] = v }
op.on(“-s”, “–second”, Array, “second option is an array”) {|v|
opts[:second] = v }
end
parser.parse!
my_method(ARGV, opts)

I’m trying to figure out the DRY way to document these options, since
they will all be identical. OptionParser documentation is in the code
and that’s great, but how do I embed documentation in the method that
also can end up in OptionParser documentation. Any ideas? (This
situation comes up frequently in my work, or I wouldn’t ask)

I’ve read through this post and it looks helpful (albeit fairly old
[will it still work]):
http://groups.google.com/group/comp.lang.ruby/browse_thread/thread/b9a6985c1695531f/6ca8309210b85d72?lnk=gst&q=dry+documentation&rnum=1#6ca8309210b85d72
but I’m not sure how I would apply it to the above situation!

Many Thanks :slight_smile:

2

rdoc has a :include tag that will allow you to include another file.
So generate your documentation with a rake task and then include that
file into RDoc

task :foo_doc => “foo.help” do
sh “rdoc”
end

file “foo.help” => “foo.rb” do
sh “ruby foo.rb -h >foo.help”
end

$ cat foo.rb

This is the foo class

Usage:

:include: foo.help