SmartAttr

This gem helps you make your model's attribute smart.You can get many useful methods with only a little code. It is especially useful for an attribute which is enumerable, because with SmartAttr you can make it more readable and convinient, and you can get many useful methods meanwhile.

Add this line to your application's Gemfile:

gem 'smart_attr'

And then execute:

$ bundle

Or install it yourself as:

$ gem install smart_attr

'Without database' means that your model does not inherit from something like ActiveRecord::Base, and does not include something like Mongoid::Document.

You can see more details in the example below:

class Movie

  include SmartAttr::Base

  smart_attr :star, config: {
    one:    { value: 1, desc: 'one star' },
    two:    { value: 2, desc: 'two star' },
    three:  { value: 3, desc: 'three star' },
    four:   { value: 4, desc: 'four star' },
    five:   { value: 5, desc: 'five star' }
  }
end

Movie.star_config_hash
# => { :one=>{:value=>1, :desc=>"one star"},
#      :two=>{:value=>2, :desc=>"two star"},
#      :three=>{:value=>3, :desc=>"three star"},
#      :four=>{:value=>4, :desc=>"four star"},
#      :five=>{:value=>5, :desc=>"five star"}
#    }

movie = Movie.new # => #<Movie:0x007fcc041b0490>

movie.star = 1  # => 1
movie.star_name # => :one
movie.star_desc # => "one star"
movie.star_one? # => true
movie.star_two? # => false

movie.star_two! # => 2
movie.star      # => 2
movie.star_two? # => true

movie.star_config # => {:value=>2, :desc=>"two star", :key=>:two}

In this situation, an instance_variable is created to store the value when you set value for the attribute.

For example:

movie = Movie.new # => #<Movie:0x007fcc041b0490>
movie.star = 3 # =>3

# By run 'movie.inspect', you can see that there is an instance_variable named '@star'.
movie.inspect # => "#<Movie:0x007fcc041b0490 @star=3>"

It is almost the same as the basic usage when used with ActiveRecord.

There is just one difference between this and the basic usage, however, there is one extra functionality when used with ActiveRecord.

The only one difference is that it will not create an instance_variable to store the value when you set value for the attribute. This is because it will store the value in the database. And the extra functionality is that it will define scope for you when used with ActiveRecord.

For example, suppose you have a class named "Movie" with database table 'movies', then you should ensure that 'movies' have column 'star' before you use 'smart_attr :star, config: { # something }'

class Song < ActiveRecord::Base

  include SmartAttr::Base

  smart_attr :star, config: {
    one:    { value: 1, desc: 'one star' },
    two:    { value: 2, desc: 'two star' },
    three:  { value: 3, desc: 'three star' },
    four:   { value: 4, desc: 'four star' },
    five:   { value: 5, desc: 'five star' }
  }

end


song = Song.new(star: 0)

song.save

song.star = 1  # => 1
song.star_name # => :one
song.star_desc # => "one star"
song.star_one? # => true
song.star_two? # => false

song.star_two! # => 2
song.star      # => 2
song.star_two? # => true

song.reload
song.star # => 1
song.star_two!
song.save
song.reload
song.star # => 2

song.star_config # => {:value=>2, :desc=>"two star", :key=>:two}

# scope
Song.star_one # The same as: Song.where(star: 1)
Song.star_two # The same as: Song.where(star: 2)

Same like used with ActiveRecord.

MRI: From 2.0.0 to 2.3.3

NOTE: 2.4.0 is not supported yet!

• Introduce SimpleCov
• Compare this to Rails' Enum, to make this gem more similar to Rails' enum so that people who are using Rails can learn this gem more easily.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/liukgg/smart_attr. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.