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Calculating Completeness of attributes of Rails Models

Hello Folks,

Hope you all are doing well. In recent week I just faced a feature on an ongoing project that is to track the completeness of model data, i.e. how many attributes of a rails model have non-empty values. In more simpler terms we can take an example of profile of a user, that how many information we need to gather from user and how much he actually provide to us. I am sharing this because I feel that it might help someone. First I tried to find some gem but I didn't get any to complete my requirement. Then I decided to go for manual implementation.

First I tried with a single model, then I used modules to do stuffs. Here I am not going deep about modules and basics of rails application. I assumed that anyone who referring this article must have a rails application and I am just starting with a simple scaffold. One more thing I implemented this one into rails 5 but I believe this can also be useful for rails 4 and rails 3.

Follow these steps:

rails g scaffold professional first_name last_name email address city state country profile_photo contact about:text current_company previous_company total_experience current_company_job_title previous_company_job_title current_company_job_description:text previous_company_job_description:text

rails db:migrate

Now put the following code into app/models/professional.rb

# This will count all fields for your model including default created_at and updated_at model fields
def self.total_columns
  column_names.count  
end

# This will display all model fields names
def self.all_columns
  column_names  
end

# This will check and counts the total non-empty fields for your model
def filled_columns
  counter = 0
  self.class.all_columns.each do |column|
    if self.attributes[column].present?
      counter += 1 
    end
  end
  counter
end

# This will calculates the percentage of completeness for your model
def completeness
  "#{(self.filled_columns * 100) / self.class.total_columns} %"
end

Wow! Its done. To check you can create a professional with some empty fields and then you can check these methods as well like this:

Professional.total_count #=> 20 (This may vary if you remove or add fields from the above sacffold command)

Professional.all_columns #=> ["id", "first_name", "last_name", "email", "address", "city", "state", "country", "profile_photo", "contact", "about", "current_company", "previous_company", "total_experience", "current_company_job_title", "previous_company_job_title", "current_company_job_description", "previous_company_job_description", "created_at", "updated_at"] (This may also vary if you remove or add fields from the above sacffold command)

Professional.last.filled_columns #=> 4 (This will depends on how many fields you left empty)

Professional.last.completeness #=> "20%" (This will also depends on how many fields you left empty)

Till this stage everything is working fine. And we can do the same thing for all our rails models. But hold on, Repeating this similar code into every model is not a standard rails practice. I suggest you to use modules for this purpose. I am assuming you have well brief of modules.

Let's create our completeness module. First remove all these methods form professional model and create a module in app/models/concerns/completeness.rb. And puts following code snippet inside this file.

module Completeness

  include ActiveSupport::Concern

  # This will contains the class methods for your model
  module ClassMethods

    def total_columns
      column_names.count  
    end

    def all_columns
      column_names  
    end
  
  end

  # This will contains the instance methods for your model
  module InstanceMethods

    def filled_columns
      counter = 0
      self.class.all_columns.each do |column|
        if self.attributes[column].present?
          counter += 1 
        end
      end
      counter
    end

    def completeness
      "#{(filled_columns * 100) / self.class.total_columns} %"
    end

  end

end

We are done here. Just one more thing we need to do now here. Add following lines into your rails model.

extend Completeness::ClassMethods
include Completeness::InstanceMethods

Note: extend is used for using class methods inside modules and include is used for using instance methods inside modules.

Thanks for reading this article. This code might not be too optimized, so if any one can help me to do so I will be glade.