Avoid dynamic finder method for single attribute using lazy-attribute gem

Lazy Attribute

This gem provides a simple and extremely flexible way to use most frequent find_by query in a model.  You can minimize find_by query of a particular attribute in a model using lazy attribute gem.

Overview

Generally in your application, if you want to fetch a user by id, you can directly use the find method

User.find(12345)

In the same way, if you want to find any user with their username / email, they have to use any one in the below

User.find_by_email('user_email@sample.com')
User.where(email: 'user_email@sample.com').first
User.find_by(email: 'user_email@sample.com')

The lazy_attribute gem will provide way to simplify the above code.

Implementation

Add this line to your application's Gemfile:

gem 'lazy-attribute'

Add this code to your model file

class User < ActiveRecord::Base
  lazy_attribute :email
end

Then anywhere in your application you can find the user with the email attribute like below

User['user_email@sample.com']

This will return user object and will return nil in case of the user not present in the db.  And you can pass optional argument like below

lazy_attribute :email, :raise_error => true

 This will raise ActiveRecord::RecordNotFound Exception instead of sending nil on record absence case.

Source

github => https://github.com/selvachezhian/lazy-attribute

rubygems => https://rubygems.org/gems/lazy-attribute