https://github.com/lucascaton/enumerate_it
Enumerations for Ruby with some magic powers! 🎩
https://github.com/lucascaton/enumerate_it
enumeration rails ruby ruby-enumerations
Last synced: about 1 month ago
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Enumerations for Ruby with some magic powers! 🎩
- Host: GitHub
- URL: https://github.com/lucascaton/enumerate_it
- Owner: lucascaton
- License: other
- Created: 2010-03-16T23:25:21.000Z (over 15 years ago)
- Default Branch: main
- Last Pushed: 2025-03-28T23:36:03.000Z (3 months ago)
- Last Synced: 2025-04-03T20:43:55.672Z (3 months ago)
- Topics: enumeration, rails, ruby, ruby-enumerations
- Language: Ruby
- Homepage:
- Size: 465 KB
- Stars: 350
- Watchers: 9
- Forks: 44
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
- awesome-ruby-toolbox - Enumerate it - Enumerations for Ruby with some magic powers! (Active Record Plugins / Active Record Enumerations)
README
# EnumerateIt
Enumerations for Ruby with some magic powers! 🎩
[](https://github.com/lucascaton/enumerate_it/actions?query=workflow%3ACI)
[](https://rubygems.org/gems/enumerate_it)
[](https://rubygems.org/gems/enumerate_it)
[](https://github.com/lucascaton/enumerate_it/releases)
**EnumerateIt** helps you declare and use enumerations in a very simple and
flexible way.
### Why would I want a gem if Rails already has native enumeration support?
Firstly, although **EnumerateIt** works well with **Rails**, it isn't required!
This means you can add it to any **Ruby** project! Secondly, you can
[define your enumerations in classes](#creating-enumerations), allowing you to
**add behavior** and **reuse** them! 😀
---
## Table of Contents
- [Installation](#installation)
- [Using with Rails](#using-with-rails)
- [Creating enumerations](#creating-enumerations)
- [Sorting enumerations](#sorting-enumerations)
- [Using enumerations](#using-enumerations)
- [FAQ](#faq)
- [Why define enumerations outside the class that uses them?](#why-define-enumerations-outside-the-class-that-uses-them)
- [Can I use `enumerate_it` gem without Rails?](#can-i-use-enumerate_it-gem-without-rails)
- [What versions of Ruby and Rails are supported?](#what-versions-of-ruby-and-rails-are-supported)
- [Can I set a value to always be at the end of a sorted list?](#can-i-set-a-value-to-always-be-at-the-end-of-a-sorted-list)
- [I18n](#i18n)
- [Translate a namespaced enumeration](#translate-a-namespaced-enumeration)
- [Handling a legacy database](#handling-a-legacy-database)
- [Changelog](#changelog)
- [Note on Patches/Pull Requests](#note-on-patchespull-requests)
- [Copyright](#copyright)
## Installation
```bash
gem install enumerate_it
```
## Using with Rails
Add the gem to your `Gemfile`:
```ruby
gem 'enumerate_it'
```
You can use a Rails generator to create both an enumeration and its locale file:
```bash
rails generate enumerate_it:enum --help
```
## Creating enumerations
Enumerations are created as classes and should be placed inside the
`app/enumerations` folder.
You can pass an array of symbols, where each symbol's value will be its
stringified version:
```ruby
class RelationshipStatus < EnumerateIt::Base
associate_values(
:single,
:married,
:divorced
)
end
```
This will generate some nice stuff:
- Constants for each enumeration value:
```ruby
RelationshipStatus::SINGLE
#=> 'single'
RelationshipStatus::MARRIED
#=> 'married'
```
- A list of all enumeration codes:
```ruby
RelationshipStatus.list
#=> ['divorced', 'married', 'single']
```
- A JSON representation:
```ruby
RelationshipStatus.to_json
#=> "[{\"value\":\"divorced\",\"label\":\"Divorced\"},{\"value\":\"married\", ...
```
- An array of options for Rails helpers, such as `select`, `select_tag`, etc.:
```ruby
RelationshipStatus.to_a
#=> [['Divorced', 'divorced'], ['Married', 'married'], ['Single', 'single']]
```
- You can retrieve a list with values for a group of enumeration constants.
```ruby
RelationshipStatus.values_for %w(MARRIED SINGLE)
#=> ['married', 'single']
```
- You can retrieve the value for a specific enumeration constant:
```ruby
RelationshipStatus.value_for('MARRIED')
#=> 'married'
```
- You can retrieve the symbol used to declare a specific enumeration value:
```ruby
RelationshipStatus.key_for(RelationshipStatus::MARRIED)
#=> :married
```
- You can iterate over the list of the enumeration's values:
```ruby
RelationshipStatus.each_value { |value| ... }
```
- You can iterate over the list of the enumeration's translations:
```ruby
RelationshipStatus.each_translation { |translation| ... }
```
- You can also retrieve all the translations of the enumeration:
```ruby
RelationshipStatus.translations
```
- You can ask for the enumeration's length:
```ruby
RelationshipStatus.length
#=> 3
```
### Sorting enumerations
When calling methods like `to_a`, `to_json` and `list`, values are sorted in the
order they were passed to `associate_values`, by default.
You can override this with the `sort_by` class method:
```ruby
class RelationshipStatus < EnumerateIt::Base
associate_values :single, :married
sort_by :translation
end
```
Accepted values for `sort_by`:
| Value | Behavior |
| :----------------------- | :------------------------------------------------------------------------------------ |
| `:none` | Uses the original order from `associate_values` |
| `:name` | Sorts by the name of each enumeration option |
| `:translation` | Sorts by their translations |
| `:normalize_translation` | Sorts by their translations normalized with NFKD unicode method (without accents) |
| `:value` | Sorts by assigned values (useful for [legacy databases](#handling-a-legacy-database)) |
## Using enumerations
The cool part is that you can use these enumerations in any class, whether
ActiveRecord-based or not:
```ruby
# ActiveRecord instance
class Person < ApplicationRecord
has_enumeration_for :relationship_status
end
```
```ruby
# Non-ActiveRecord instance
class Person
extend EnumerateIt
attr_accessor :relationship_status
has_enumeration_for :relationship_status
end
```
> **Note:** If the enumeration class name differs from the attribute name, use
> the `with` option:
>
> `has_enumeration_for :relationship_status, with: RelationshipStatus`
This will create:
- A "humanized" version of the hash's key to humanize the attribute's value:
```ruby
p = Person.new
p.relationship_status = RelationshipStatus::DIVORCED
p.relationship_status_humanize
#=> 'Divorced'
```
- A translation for your options, if you include a locale to represent it (see
more in the [I18n section](#i18n)).
```ruby
p = Person.new
p.relationship_status = RelationshipStatus::DIVORCED
p.relationship_status_humanize
#=> 'Divorciado'
```
- The associated enumerations, which can be retrieved with the `enumerations`
class method:
```ruby
Person.enumerations
#=> { relationship_status: RelationshipStatus }
```
- A helper method for each enumeration option, if you pass the `create_helpers`
option as `true`:
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status, with: RelationshipStatus, create_helpers: true
end
p = Person.new
p.relationship_status = RelationshipStatus::MARRIED
p.married?
#=> true
p.divorced?
#=> false
```
It's also possible to "namespace" the created helper methods, passing a hash
to the `create_helpers` option. This can be useful when two or more of the
enumerations used share the same constants:
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status,
with: RelationshipStatus, create_helpers: { prefix: true }
end
p = Person.new
p.relationship_status = RelationshipStatus::MARRIED
p.relationship_status_married?
#=> true
p.relationship_status_divorced?
#=> false
```
You can define polymorphic behavior for the enumeration values, so you can
define a class for each of them:
```ruby
class RelationshipStatus < EnumerateIt::Base
associate_values :married, :single
class Married
def saturday_night
'At home with the kids'
end
end
class Single
def saturday_night
'Party hard!'
end
end
end
class Person < ApplicationRecord
has_enumeration_for :relationship_status,
with: RelationshipStatus, create_helpers: { polymorphic: true }
end
p = Person.new
p.relationship_status = RelationshipStatus::MARRIED
p.relationship_status_object.saturday_night
#=> 'At home with the kids'
p.relationship_status = RelationshipStatus::SINGLE
p.relationship_status_object.saturday_night
#=> 'Party hard!'
```
You can also change the suffix `_object`, using the `suffix` option:
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status,
with: RelationshipStatus, create_helpers: { polymorphic: { suffix: '_mode' } }
end
p.relationship_status_mode.saturday_night
```
The `create_helpers` also creates some mutator helper methods, that can be
used to change the attribute's value.
```ruby
p = Person.new
p.married!
p.married?
#=> true
```
- A scope method for each enumeration option if you pass the `create_scopes`
option as `true`:
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status, with: RelationshipStatus, create_scopes: true
end
Person.married.to_sql
#=> SELECT "users".* FROM "users" WHERE "users"."relationship_status" = "married"
```
The `:create_scopes` also accepts `prefix` option.
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status,
with: RelationshipStatus, create_scopes: { prefix: true }
end
Person.relationship_status_married.to_sql
```
- An inclusion validation (if your class can manage validations and responds to
`validates_inclusion_of`):
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status, with: RelationshipStatus
end
p = Person.new(relationship_status: 'invalid')
p.valid?
#=> false
p.errors[:relationship_status]
#=> 'is not included in the list'
```
- A presence validation (if your class can manage validations and responds to
`validates_presence_of` and you pass the `required` options as `true`):
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status, required: true
end
p = Person.new relationship_status: nil
p.valid?
#=> false
p.errors[:relationship_status]
#=> "can't be blank"
```
If you pass the `skip_validation` option as `true`, it will not create any
validations:
```ruby
class Person < ApplicationRecord
has_enumeration_for :relationship_status, with: RelationshipStatus, skip_validation: true
end
p = Person.new(relationship_status: 'invalid')
p.valid?
#=> true
```
Remember that you can add validations to any kind of class and not only
`ActiveRecord` ones.
## FAQ
#### Why define enumerations outside the class that uses them?
- It's clearer.
- You can add behavior to the enumeration class.
- You can reuse the enumeration inside other classes.
#### Can I use `enumerate_it` gem without Rails?
You sure can! 😄
#### What versions of Ruby and Rails are supported?
- **Ruby**: `3.0+`
- **Rails**: `6.0+`
All versions are tested via
[GitHub Actions](https://github.com/lucascaton/enumerate_it/blob/HEAD/.github/workflows/ci.yml).
#### Can I set a value to always be at the end of a sorted list?
Yes,
[see more details here](https://github.com/lucascaton/enumerate_it/issues/60).
## I18n
I18n lookup is provided for both `_humanized` and `Enumeration#to_a` methods,
given the hash key is a Symbol. The I18n strings are located on
`enumerations..`:
```yaml
# Your locale file
pt-BR:
enumerations:
relationship_status:
married: Casado
```
```ruby
class RelationshipStatus < EnumerateIt::Base
associate_values(
:married,
:single
)
end
p = Person.new
p.relationship_status = RelationshipStatus::MARRIED
p.relationship_status_humanize # Existent key
#=> 'Casado'
p.relationship_status = RelationshipStatus::SINGLE
p.relationship_status_humanize # Non-existent key
#=> 'Single'
```
You can also translate specific values:
```ruby
status = RelationshipStatus::MARRIED
RelationshipStatus.t(status)
#=> 'Casado'
```
### Translate a namespaced enumeration
In order to translate an enumeration in a specific namespace (say
`Design::Color`), use the following structure:
```yaml
pt-BR:
enumerations:
"design/color":
blue: Azul
red: Vermelho
```
## Handling a legacy database
**EnumerateIt** can help you build a Rails application around a legacy database
which was filled with those small and unchangeable tables used to create foreign
key constraints everywhere, like the following example:
```sql
Table "public.relationship_status"
Column | Type | Modifiers
-------------+---------------+-----------
code | character(1) | not null
description | character(11) |
Indexes:
"relationship_status_pkey" PRIMARY KEY, btree (code)
SELECT * FROM relationship_status;
code | description
---- +--------------
1 | Single
2 | Married
3 | Divorced
```
You might also have something like a `users` table with a `relationship_status`
column and a foreign key pointing to the `relationship_status` table.
While this is a good thing from the database normalization perspective, managing
these values in tests is very hard. Doing database joins just to get the
description of some value is absurd. And, more than this, referencing them in
the code using
[magic numbers]() was
terrible and meaningless: what does it mean when we say that someone or
something is `2`?
To solve this, you can pass a **hash** to your enumeration values:
```ruby
class RelationshipStatus < EnumerateIt::Base
associate_values(
single: 1,
married: 2,
divorced: 3
)
end
```
```ruby
RelationshipStatus::MARRIED
#=> 2
```
You can also sort it by its **value** using `sort_by :value`.
## Changelog
Changes follows the [Semantic Versioning](https://semver.org/) specification and
you can see them on the [releases page](../../releases).
## Note on Patches/Pull Requests
- Fork the project.
- Make your feature addition or bug fix.
- Add tests for it. This is important so we don't break it in a future version
unintentionally.
- [Optional] Run the tests against a specific Gemfile:
`bundle exec appraisal rails_8.0 rake spec`.
- Run the tests against all supported versions: `bundle exec rake`
- Commit, but please do not mess with `Rakefile`, version, or history.
- Send a Pull Request. Bonus points for topic branches.
## Copyright
Copyright (c) 2010-2025 Cássio Marques and Lucas Caton. See `LICENSE` file for
details.