Wowwww I am experiencing the magic of Metaprogramming what a beauty you sweety!!!! .please don’t get embarrassed that I am going to write a post about my girl friend yes absolutely right Metaprogramming ruby is my new girl friend ,what a beauty it has if I start explain about its beauty you will also become a great fan of it.lets implement OpenStruct using Ruby Metaprogramming. OpenStruct kya hei ?? OpenStruct is a data structure close to hash ,it allows to define key and values and access like a hash. If you call the key with object as a receiver corresponding value will be returned.

require ‘ostruct’
str = OpenStruct.new
str.name=”Vinod”
str.age=”23”

puts  str.age #=> 23

puts str.name #=> “Vinod”

Here we will try to implement the functionality of Openstruct using Ruby Metaprogramming

class MyStruct
	def initialize
		@my_hash={}   #empty hash

	end
	def method_missing(name,*args)
		new_key = name.to_s  #convert method name to string

		if new_key =~ /=$/  #check  whether ‘=’ pattern is available in method name

		@my_hash[new_key.chop] = args[0]  #assign value to the corresponding  key in a hash

		else
			@my_hash[new_key]   #assign empty value to hash

		end
	end
end
vcet=MyStruct.new
vcet.nick = "vinod"
puts vcet.nick
vcet.age = 23
puts vcet.age

####Explanation: +create an empty hash named @my_hash = {}. +key name is gonna be dynamic so we need to implement method_missing() to handle the unknown method and the arguments(name will contain method name and args[0] will contain the value). +if the method name has a pattern of ‘=’ then method name will be passed as a key in to the hash and value assigned to method will be value of the key in hash. +if the method is not in such pattern then method name will be passed as a key in to hash and value will be null. +here initialize ‘vcet’ object for MyStruct class and call vcet.nick=”Vinod”. +here nick= will be the method called and method_missing() will be called because it is an unknown method and (nick= and “Vinod”) will be passed as an argument. *hash will be defined as my_hash[nick]=”Vinod”.