Ruby class template based on attribs and a passed hash

gistfile1.rb

class Base

  def initialize args
    update args
  end
  
  def update args
    args.each do |k,v|
      send "#{k}=", v if respond_to? k 
    end
  end

end


class Person < Base
  attr_accessor :firstname, :lastname, :age
end


class Dog < Base
  attr_accessor :name, :age
end

The good thing of those classes is that you can initialize them passing a Hash with the attribs:

p = Person.new :firstname => 'John', :lastname => 'Smith'
#<Person:0x8db4284 @firstname="John", @lastname="Smith">
p.firstname
# => "John"
p.lastname
# => "Smith"
p.age
# => nil

And the created objects will just take the declared attribs:

d = Dog.new :name => 'Bobby', :lastname => 'Smith', :age => 7
#<Dog:0x8d05d74 @name="Bobby", @age=7>
d.name
# => "Bobby"
d.lastname
# NoMethodError: undefined method `lastname' for #<Dog:0x8d05d74 @name="Bobby">
d.age
# => 7

The method update is not really necessary but I found it useful for update the object values after it is created. For example:

p
#<Person:0x8db4284 @firstname="John", @lastname="Smith">
p.update :firstname => "Johnny", :age => 17
 => {:firstname=>"Johnny", :age=>17}
p
#<Person:0x8db4284 @firstname="Johnny", @lastname="Smith", @age=17>