Interchangeable

Create and maintain interchangeable components in Ruby.

Usage

class MyApi
  def api_key
    "abc"
  end
end

can become

class MyApi
  interchangeable_method :api_key
end

Elsewhere in your application, you can define the method like so:

  Interchangeable.define MyApi, :api_key { 'anything' }

  MyApi.new.api_key # 'anything'

You can also provide a default implementation that can be overridden elsewhere:

class MyApi
  interchangeable_method(:api_key) { 'abc' }
end

MyApi.new.api_key # 'abc'

But why bother doing this?

Interchangeable will provide you a list of the methods you have defined, as well as some helpful information.

class MyApi
  interchangeable_describe "this is an apple"
  interchangeable_method :apple
  
  interchangeable_describe "this is an orange"
  interchangeable_method(:orange) { 'orange' }
  
  interchangeable_describe "this is a banana"
  interchangeable_method :banana
end

Interchangeable.define(MyApi, :banana) { 'banana' }


Interchangeable.methods # [<target=MyApi, method_name=:apple,  implemented=false, default=false, description="this is an apple">,
                        #  <target=MyApi, method_name=:orange, implemented=true,  default=true,  description="this is an orange">,
                        #  <target=MyApi, method_name=:banana, implemented=true,  default=false, description="this is a banana">]

This information can be helpful if you have a reusable system with many interchangeable parts.

Installation

Add this line to your application's Gemfile:

gem 'interchangeable'

And then execute:

$ bundle

Or install it yourself as:

$ gem install interchangeable