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Victor Hazbun
Victor Hazbun

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Refactoring towards decorators in Rails

Decorators

They wrap an object and extend its functionality without modifying the object itself.

The problem

Say you have the following view.

 <p>Name: <%= @company.name.titleize %></p>

 <p>Email: <%= @company.email_private? 'Private' : @company.email %></p>

 <p>Sign Up At: <%= @company.sign_up_at.strftime('%d. %m. %Y.') %></p>
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It's bad because the view should not care about how to display the data, it should just display it.

The Decorator object

class CompanyDecorator < SimpleDelegator
  def display_name
    name.titleize
  end

  def protected_email
    return "Private" if email_private?
    email
  end

  def formatted_sign_up_at
    sign_up_at.strftime("%d %b %Y")
  end
end
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The implementation

Nice, let's see how the controller looks now.

class CompanyController < ApplicationController
  def show
    company = Company.find(params[:id])
    @decorated_company = CompanyDecorator.new(company)
  end
end
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Now, the view

 <p>Name: <%= @decorated_company.display_name %></p>

 <p>Email: <%= @decorated_company.protected_email %></p>

 <p>Birthday: <%= @decorated_company.formatted_sign_up_at %></p>
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Final thoughts

Not only looks better, testing this approach is much simpler.

This does not only applies for Rails apps, this pattern could be used anywhere in Ruby.

Top comments (1)

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fernandomaia profile image
Fernando Maia

Nice and clean solution. Awesome!