URL protocol handling in RubyCocoa

1. README.mkdn

Lots of help from: http://codeintensity.blogspot.com/2008/01/rubycocoa-rocks.html

This is what I learned from attempting to create a RubyCocoa, Core Data, non-document-based application in Xcode that could handle a 'URL scheme' as defined by OS X.

2. rb_main.rb

# This file should be created by default - no need to
# modify it if so (this is the default content).
require 'osx/cocoa'

def rb_main_init
  path = OSX::NSBundle.mainBundle.resourcePath.fileSystemRepresentation
  rbfiles = Dir.entries(path).select {|x| /\.rb\z/ =~ x}
  rbfiles -= [ File.basename(__FILE__) ]
  rbfiles.each do |path|
    require( File.basename(path) )
  end
end

if $0 == __FILE__ then
  rb_main_init
  OSX.NSApplicationMain(0, nil)
end

3. Info.plist

<key>CFBundleURLTypes</key>
  <array>
    <dict>
      <key>CFBundleURLName</key>
      <string>A Something URL that points to a Something</string>
      <key>CFBundleURLSchemes</key>
      <array>
        <string>smth</string>
      </array>
    </dict>
  </array>

4. string.rb

class String
  # Translate a four-character code to some numeric value
  # apparently used internally by OS X.
  def to_fcc
    raise unless self.length == 4
    self.unpack('N').first
  end
end

5. SomethingsController.rb

# This will replace NSArrayController as the class of your
# Core Data object's controller. In my case, my primary
# model is that for a 'Something'. In the Interface Builder,
# after creating an NSArrayController and attaching it to
# the relevant elements of your interface, make sure it
# uses SomethingsController instead of the default
# NSArrayController as the 'class'.

class SomethingsController < OSX::NSArrayController
  def awakeFromNib
    registerMyApp
    # Whatever else...
  end
  
  def registerMyApp
    OSX::NSAppleEventManager.sharedAppleEventManager.
      setEventHandler_andSelector_forEventClass_andEventID_(
        self, :getUrl_withReplyEvent, 'GURL'.to_fcc, 'GURL'.to_fcc)
  end

  def getUrl_withReplyEvent(event, reply)
    url = event.paramDescriptorForKeyword('----'.to_fcc).stringValue
    # Utilize the URL in whatever way you desire.
  end
end