Initial project files.

Author: jocubeit

CHANGELOG.md

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+# Change Log
+
+## v1.0.0
+- Initial release.

Gemfile

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+source 'https://rubygems.org'
+ruby '2.4.2'

Gemfile.lock

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+GEM
+  remote: https://rubygems.org/
+  specs:
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+
+RUBY VERSION
+   ruby 2.4.2p198
+
+BUNDLED WITH
+   1.16.2

MIT-LICENSE.md

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+Copyright 2018 Brightcommerce, Inc. All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+# AttrSequence
+
+AttrSequence is an ActiveRecord concern that generates scoped sequential numbers for models. This gem provides an `attr_sequence` macro that automatically assigns a unique, sequential number to each record. The sequential number is not a replacement for the database primary key, but rather adds another way to retrieve the object without exposing the primary key.
+
+AttrSequence has been extracted from the Brightcommerce platform and is now used in multiple other software projects.
+
+## Installation
+
+To install add the line to your `Gemfile`:
+
+``` ruby
+gem 'attr_sequence'
+```
+
+And run `bundle install`.
+
+The following configuration defaults are used by AttrSequence:
+
+``` ruby
+AttrSequence.configure do |config|
+  config.column = :number
+  config.start_at = 1
+end
+```
+
+You can override them by generating an initializer using the following command:
+
+``` bash
+rails generate attr_sequence:initializer
+```
+
+This will generate an initializer file in your project's `config/initializers` called `attr_sequence.rb` directory.
+
+## Usage
+
+It's generally a bad practice to expose your primary keys to the world in your URLs. However, it is often appropriate to number objects in sequence (in the context of a parent object).
+
+For example, given a Question model that has many Answers, it makes sense to number answers sequentially for each individual question. You can achieve this with AttrSequence:
+
+``` ruby
+class Question < ActiveRecord::Base
+  has_many :answers
+end
+
+class Answer < ActiveRecord::Base
+  include AttrSequence
+  belongs_to :question
+  attr_sequence scope: :question_id
+end
+```
+
+To autoload AttrSequence for all models, add the following to an initializer:
+
+``` ruby
+require 'attr_sequence/active_record'
+```
+
+You then don't need to `include AttrSequence` in any model.
+
+To add a sequential number to a model, first add an integer column called `:number` to the model (or you many name the column anything you like and override the default). For example:
+
+``` bash
+rails generate migration add_number_to_answers number:integer
+rake db:migrate
+```
+
+Then, include the concern module and call the `attr_sequence` macro in your model class:
+
+``` ruby
+class Answer < ActiveRecord::Base
+  include AttrSequence
+  belongs_to :question
+  attr_sequence scope: :question_id
+end
+```
+
+The scope option can be any attribute, but will typically be the foreign key of an associated parent object. You can even scope by multiple columns for polymorphic relationships:
+
+``` ruby
+class Answer < ActiveRecord::Base
+  include AttrSequence
+  belongs_to :questionable, polymorphic: true
+  attr_sequence scope: [:questionable_id, :questionable_type]
+end
+```
+
+Multiple sequences can be defined by using the macro multiple times:
+
+``` ruby
+class Answer < ActiveRecord::Base
+  include AttrSequence
+  belongs_to :account
+  belongs_to :question
+
+  attr_sequence column: :question_answer_number, scope: :question_id
+  attr_sequence column: :account_answer_number, scope: :account_id
+end
+```
+
+## Schema and data integrity
+
+*This gem is only concurrent-safe for PostgreSQL databases.* For other database systems, unexpected behavior may occur if you attempt to create records concurrently.
+
+You can mitigate this somewhat by applying a unique index to your sequential number column (or a multicolumn unique index on sequential number and scope columns, if you are using scopes). This will ensure that you can never have duplicate sequential numbers within a scope, causing concurrent updates to instead raise a uniqueness error at the database-level.
+
+It is also a good idea to apply a not-null constraint to your sequential number column as well if you never intend to skip it.
+
+Here is an example migration for an `Answer` model that has a `:number` scoped to a `Question`:
+
+``` ruby
+# app/db/migrations/20180101000000_create_answers.rb
+class CreateAnswers < ActiveRecord::Migration
+  def change
+    create_table :answers do |table|
+      table.references :question
+      table.column :number, :integer, null: false
+      table.index [:number, :question_id], unique: true
+    end
+  end
+end
+```
+
+## Configuration
+
+### Overriding the default sequential ID column
+
+By default, AttrSequence uses the `number` column and assumes it already exists. If you wish to store the sequential number in different integer column, simply specify the column name with the `:column` option:
+
+``` ruby
+attr_sequence scope: :question_id, column: :my_sequential_id
+```
+
+### Starting the sequence at a specific number
+
+By default, AttrSequence begins sequences with 1. To start at a different integer, simply set the `start_at` option:
+
+``` ruby
+attr_sequence start_at: 1000
+```
+
+You may also pass a lambda to the `start_at` option:
+
+``` ruby
+attr_sequence start_at: lambda { |r| r.computed_start_value }
+```
+
+### Indexing the sequential number column
+
+For optimal performance, it's a good idea to index the sequential number column on sequenced models.
+
+### Skipping sequential ID generation
+
+If you'd like to skip generating a sequential number under certain conditions, you may pass a lambda to the `skip` option:
+
+``` ruby
+attr_sequence skip: lambda { |r| r.score == 0 }
+```
+
+## Example
+
+Suppose you have a question model that has many answers. This example demonstrates how to use AttrSequence to enable access to the nested answer resource via its sequential number.
+
+``` ruby
+# app/models/question.rb
+class Question < ActiveRecord::Base
+  has_many :answers
+end
+
+# app/models/answer.rb
+class Answer < ActiveRecord::Base
+  include AttrSequence
+  belongs_to :question
+  attr_sequence scope: :question_id
+
+  # Automatically use the sequential number in URLs
+  def to_param
+    self.number.to_s
+  end
+end
+
+# config/routes.rb
+resources :questions do
+  resources :answers
+end
+
+# app/controllers/answers_controller.rb
+class AnswersController < ApplicationController
+  def show
+    @question = Question.find(params[:question_id])
+    @answer = @question.answers.find_by(number: params[:id])
+  end
+end
+```
+
+Now, answers are accessible via their sequential numbers:
+
+```
+http://example.com/questions/5/answers/1  # Good
+```
+
+instead of by their primary keys:
+
+```
+http://example.com/questions/5/answer/32454  # Bad
+```
+
+## Dependencies
+
+AttrSequence gem has the following runtime dependencies:
+- activerecord >= 5.1.4
+- activesupport >= 5.1.4
+
+## Compatibility
+
+Tested with MRI 2.4.2 against Rails 5.2.2.
+
+## Contributing
+
+1. Fork it
+2. Create your feature branch (`git checkout -b my-new-feature`)
+3. Commit your changes (`git commit -am 'Add some feature'`)
+4. Push to the branch (`git push origin my-new-feature`)
+5. Create new Pull Request
+
+## Credit
+
+This gem was written and is maintained by [Jurgen Jocubeit](https://github.com/JurgenJocubeit), CEO and President Brightcommerce, Inc.
+
+## License
+
+The gem is available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).
+
+## Copyright
+
+Copyright 2018 Brightcommerce, Inc.

Rakefile

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+begin
+  require 'bundler/setup'
+rescue LoadError
+  puts 'You must `gem install bundler` and `bundle install` to run rake tasks'
+end
+
+Bundler::GemHelper.install_tasks
+
+require 'rake/testtask'
+
+Rake::TestTask.new(:test) do |t|
+  t.libs << 'lib'
+  t.libs << 'test'
+  t.pattern = 'test/**/*_test.rb'
+  t.verbose = false
+end
+
+task default: :test

attr_sequence.gemspec

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+require "./lib/attr_sequence/version"
+
+Gem::Specification.new do |gem|
+  gem.name        = "attr_sequence"
+  gem.version     = AttrSequence::Version::Compact
+  gem.summary     = AttrSequence::Version::Summary
+  gem.description = AttrSequence::Version::Description
+  gem.authors     = AttrSequence::Version::Author
+  gem.email       = AttrSequence::Version::Email
+  gem.homepage    = AttrSequence::Version::Homepage
+  gem.license     = AttrSequence::Version::License
+  gem.metadata    = AttrSequence::Version::Metadata
+  gem.platform    = Gem::Platform::RUBY
+
+  gem.required_ruby_version = '>= 2.3'
+  gem.require_paths = ["lib"]
+  gem.files = Dir[
+    "{lib}/**/*",
+    "MIT-LICENSE.md",
+    "CHANGELOG.md",
+    "README.md"
+  ]
+
+  gem.add_runtime_dependency 'activerecord', '>= 5.1.4'
+  gem.add_runtime_dependency 'activesupport', '>= 5.1.4'
+end

lib/attr_sequence.rb

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+require 'attr_sequence/attr_sequence'
+require 'attr_sequence/configuration'
+require 'attr_sequence/version'
+
+module AttrSequence
+  extend ActiveSupport::Autoload
+
+  @@configuration = nil
+
+  def self.configure
+    @@configuration = Configuration.new
+    yield(configuration) if block_given?
+    configuration
+  end
+
+  def self.configuration
+    @@configuration || configure
+  end
+
+  def self.method_missing(method_sym, *arguments, &block)
+    if configuration.respond_to?(method_sym)
+      configuration.send(method_sym)
+    else
+      super
+    end
+  end
+
+  def self.respond_to?(method_sym, include_private = false)
+    if configuration.respond_to?(method_sym, include_private)
+      true
+    else
+      super
+    end
+  end
+end

lib/attr_sequence/active_record.rb

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+ActiveRecord::Base.send :include, AttrSequence