A ruby DSL for making timelines.

chronology.rb

require 'date'

module Chronograph
	class Timeline
        include Enumerable

		class Event < Struct.new(:name, :date, :desc)
            attr_accessor :name, :date, :desc
            def initialize(name, date, desc)
                raise TypeError.new("date must be a date") unless date.is_a? Date
				raise TypeError.new("name has to be a name or symbol") unless name.is_a?(String) || name.is_a?(Symbol)
				raise TypeError.new("desc must be a string") unless desc.is_a? String

                @name = name
                @date = date
                @desc = desc
            end
			
		end

		class Person < Struct.new(:name, :birth, :death, :desc, :events)
			attr_reader :name, :birth, :death, :desc, :events
			def initialize(name, birth, death, desc, *events)
				raise TypeError.new("name has to be a name or symbol") unless name.is_a?(String) || name.is_a?(Symbol)
				raise TypeError.new("birth and death must be a date") unless birth.is_a?(Date) && death.is_a?(Date)
				
				raise TypeError.new("desc must be a string") unless desc.is_a? String
				
				@name = name
				@birth = birth
				@death = death
				@desc = desc
				@events = events
			end
			
			def events
				[begining_event, ending_event, @events].flatten
			end

            def begining_event
                Event.new("Birth of #{name}", birth, "#{name} is born")
            end

            def ending_event
                 Event.new("Death of #{name}", death, "#{name} dies")
            end

		end

        class LongEvent < Person
            def begining_event                               
                Event.new("Begining of #{name}", birth, "#{name} begins")
            end

            def ending_event
                Event.new("End of #{name}", death, "#{name} ends")
            end
        end

        class War < LongEvent; end

		def initialize(&block)
			@people = []
			@events = []
			instance_eval(&block)
		end

        def each(&block)
            consolidate.each(&block)
        end

		def person(name, birth, death, desc, &block)
			@life_events = []
			def life_event(name, date, desc)
				@life_events << Event.new(name, date, desc)
			end
			
			instance_eval(&block) if block != nil
			
			@people << Person.new(name, birth, death, desc, *@life_events)
		end
		
		def long_event(name, birth, death, desc, &block)
			@long_events = []
			def le_event(name, date, desc)
				@long_events << Event.new(name, date, desc)
			end
			
			instance_eval(&block) if block != nil
			
			@people << LongEvent.new(name, birth, death, desc, *@long_events)
		end



		def event(name, date, desc)
			@events << Event.new(name, date, desc)
		end
		
		def today
			event "Today", Date.today, "this day"
		end

		def consolidate
			t = []
			t << @events << @people.map { |x| x.events }
			return t.flatten.sort { |a, b| a.date <=> b.date }
		end
		
		def get_text
			consolidate.map { |x| "#{x.date}: #{x.name}, #{x.desc}" }.join("\n")
		end

		def get_html_table
			r = "<table>"
			consolidate.each do |x|
				r += "<tr>"
				r += [x.date, x.name, x.desc].map { |x| "<td>" + x.to_s + "</td>"}.join
				r += "</tr>"
			end
			r += "</table>"
		end
	end
end


if $0 == __FILE__
	t = Chronograph::Timeline.new do
		person "Mr. Ruby", Date.new(1654), Date.new(2010), "He was awesome" do
			life_event "Mr. Ruby leaves Japan", Date.new(2000), "It was easy"

            long_event "War against Java", Date.new(2005), Date.new(2007), "It was needed" do
                le_event "Battle of the MRI", Date.new(2005, 5, 6), "Mr. Ruby almost lost"
                le_event "Battle of the JVM", Date.new(2005, 10, 31), "This was one scary halloween for Javaland"
            end
		end
		
		event "Javaland founded", Date.new(1990), "1000s die"
		
		
		today
	end

    #t.each { |x| puts x.inspect }
	puts t.get_text
end