Building a rack map via sinatra app inheritance.

config.ru

require 'fedora'

Fedora.map.each do |route, app|
  map(route) { run app }
end

fedora.rb

# Copyright (c) 2011,2012 Jonathan Stott
#
# Permission  is  hereby granted, free of charge, to any person ob-
# taining a copy of  this  software  and  associated  documentation
# files  (the "Software"), to deal in the Software without restric-
# tion, including without limitation the rights to use, copy, modi-
# fy, merge, publish, distribute, sublicense, and/or sell copies of
# the Software, and to permit persons to whom the Software is  fur-
# nished to do so, subject to the following conditions:
# 
# The  above  copyright  notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF  ANY  KIND,
# EXPRESS  OR  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE  AND  NONIN-
# FRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER  IN  AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN  THE
# SOFTWARE.

class Fedora < Sinatra::Base
  def self.inherited(klass)
    super
    descendents.push(klass)
  end

  def self.descendents
     @descendents ||= []
  end

  def self.map
    Hash[descendents.map { |d| [d.namespace, d] }]
  end

  def self.namespace(value=nil)
    return (@namespace || "/#{name}") if value.nil?
    @namespace = value
  end
end

class Test < Fedora
  namespace "/"
  get '/:id' do
  end
end

class Example < Fedora
  get '' do
  end
end