Background & Objectives

Congrats for reaching this exercise. We will now do some meta-programing; code that produces code. We can write code to dynamically generate classes, or methods inside a class. This is very powerful, and quite easily done with Ruby.

Think about your Post class. You have methods like save, self.find and self.all. Imagine having another model, say User or ProgrammingLanguage. You'll need the exact same methods right?

This means we want Post, User and ProgrammingLanguage to share a common behavior, which can be achieved through inheritance:

class Record
  # The shared code
end

class Post < Record
end

class User < Record
end

class ProgrammingLanguage < Record
end

Specs

Implement the Record class so that it has all the behavior expected from a model:

Class methods:

• new
• attribute_names
• create
• find
• all
• first
• second
• third
• last
• count
• destroy_all

Instance methods:

• attributes
• update
• save
• destroy
• reload
• assign_attributes

Do not write any code in your Post, User, and ProgrammingLanguage classes! This constraint will help you discover Ruby awesomeness.

Further suggestions & resources

• There is a send method on all classes.
• You can dynamically set an instance variable with instance_variable_set
• You can dynamically read an instance variable with instance_variable_get