Daily Refactor #39: Substitute Algorithm for Checking the Settings

By Eric Davis on March 22, 2010 in General

Since I’m planning to release an update to my StuffToDo plugin next, I decided it could use a week of refactoring in order to clean it up.

The Refactoring

Today I did the second part of the refactoring from yesterday to clean up the StuffToDo plugin’s #using_projects_as_items? and #using_issues_as_items? methods. This time I used “substitute algorithm” to refactor the inner logic.

Before

# app/models/stuff_to_do.rb
class StuffToDo &lt; ActiveRecord::Base
  def self.using_projects_as_items?
    use_setting == &#039;All&#039; || use_setting  == &#039;Only Projects&#039;
  end
 
  def self.using_issues_as_items?
    use_setting == &#039;All&#039; || use_setting  == &#039;Only Issues&#039;
  end
end

After

class StuffToDo &lt; ActiveRecord::Base
  def self.using_projects_as_items?
    [&#039;All&#039;, &#039;Only Projects&#039;].include?(use_setting)
  end
 
  def self.using_issues_as_items?
    [&#039;All&#039;, &#039;Only Issues&#039;].include?(use_setting)
  end
end

Review

This was a simple refactoring but it really made the intent of the methods clear. Removing the extra method calls and using an Array of valid values will make it easier to modify later. This refactoring also made flay happy enough to report that the duplication has been completely removed.

Reference commit

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About Eric Davis

I founded Little Stream Software where I provide Redmine and ChiliProject services to help projects teams. I also created an ebook, Redmine Tips, were I show you how to become more productive using Redmine. I am also the author of Refactoring Redmine, where I go about refactoring Rails using Redmine as an example.

View all posts by Eric Davis →

redmine, refactoring, ruby, substitute-algorithm

← Daily Refactor #38: Extract Method in StuffToDo

Daily Refactor #40: Extract Method in StuffToDo#available →

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I am the founder of Little Stream Software, a software company that specializes in Ruby on Rails and Redmine development.

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