Example Strategy Factory

example_strategy_factory.rb

# this would be called in the controller, 
# whose return value is the Strategy class

class CandidateJobDocumentStrategyFactory
  def self.strategy_for(document_type)
    case document_type
    when :resume       then resume_strategy
    when :cover_letter then cover_letter_strategy
    when :application  then application_strategy
    end
  end
  
  def self.resume_strategy
    ResumeStrategy
  end
  
  def self.cover_letter_strategy
    CoverLetterStrategy
  end
  
  def self.application_strategy
    ApplicationStrategy
  end
  
  class ResumeStrategy
    def self.execute(candidate_job, resume)
      # business logic of associating the resume to the candidate_job
    end
  end
end