# Qonfig · [![Gem Version](https://badge.fury.io/rb/qonfig.svg)](https://badge.fury.io/rb/qonfig) [![Build Status](https://travis-ci.org/0exp/qonfig.svg?branch=master)](https://travis-ci.org/0exp/qonfig) [![Coverage Status](https://coveralls.io/repos/github/0exp/qonfig/badge.svg?branch=master)](https://coveralls.io/github/0exp/qonfig?branch=master)

Config. Defined as a class. Used as an instance. Support for inheritance and composition.
Lazy instantiation. Thread-safe. Command-style DSL. Extremely simple to define. Extremely simple to use. That's all.

## Installation

```ruby
gem 'qonfig'
```

```shell
$ bundle install
# --- or ---
$ gem install 'qonfig'
```

```ruby
require 'qonfig'
```

## Usage

- [Definition and Access](#definition-and-access)
- [Configuration](#configuration)
- [Inheritance](#inheritance)
- [Composition](#composition)
- [Hash representation](#hash-representation)
- [Config reloading](#config-reloading) (reload config definitions and option values)
- [Clear options](#clear-options) (set to nil)
- [State freeze](#state-freeze)
- [Settings as Predicates](#settings-as-predicates)
- [Load from YAML file](#load-from-yaml-file)
- [Load from ENV](#load-from-env)
- [Load from \_\_END\_\_](#load-from-__end__) (aka `load_from_self`)
- [Smart Mixin](#smart-mixin) (`Qonfig::Configurable`)

---

### Definition and Access

```ruby
class Config < Qonfig::DataSet
  # nil by default
  setting :project_id

  # nested setting
  setting :vendor_api do
    setting :host, 'app.service.com'
  end

  setting :enable_graphql, false

  # nested setting reopening
  setting :vendor_api do
    setting :user, 'test_user'
  end
end

config = Config.new

# get option value via method
config.settings.project_id # => nil
config.settings.vendor_api.host # => 'app.service.com'
config.settings.vendor_api.user # => 'test_user'
config.settings.enable_graphql # => false

# get option value via index (with indifferent (string / symbol / mixed) access)
config.settings[:project_id] # => nil
config.settings[:vendor_api][:host] # => 'app.service.com'
config.settings[:vendor_api][:user] # => 'test_user'
config.settings[:enable_graphql] # => false

# get option value via index (with indifferent (string / symbol / mixed) access)
config.settings['project_id'] # => nil
config.settings['vendor_api']['host'] # => 'app.service.com'
config.settings['vendor_api']['user'] # => 'test_user'
config.settings['enable_graphql'] # => false

# get option value directly via index (with indifferent access)
config['project_id'] # => nil
config['enable_graphql'] # => false
config[:project_id] # => nil
config[:enable_graphql] # => false

# get option value in Hash#dig manner (and fail when the required key does not exist)
config.dig(:vendor_api, :host) # => 'app.service.com' # (key exists)
config.dig(:vendor_api, :port) # => Qonfig::UnknownSettingError # (key does not exist)
```

---

### Configuration

```ruby
class Config < Qonfig::DataSet
  setting :testing do
    setting :engine, :rspec
    setting :parallel, true
  end

  setting :geo_api do
    setting :provider, :google_maps
  end

  setting :enable_middlewares, false
end

config = Config.new

# configure via proc
config.configure do |conf|
  conf.enable_middlewares = true
  conf.geo_api.provider = :yandex_maps
  conf.testing.engine = :mini_test
end

# configure via settings object (by option name)
config.settings.enable_middlewares = false
config.settings.geo_api.provider = :apple_maps
config.settings.testing.engine = :ultra_test

# configure via settings object (by setting key)
config.settings[:enable_middlewares] = true
config.settings[:geo_api][:provider] = :rambler_maps
config.settings[:testing][:engine] = :mega_test

# instant configuration via proc
config = Config.new do |conf|
  conf.enable_middlewares = false
  conf.geo_api.provider = :amazon_maps
  conf.testing.engine = :crypto_test
end

# using a hash
config = Config.new(
  testing: { engine: :mini_test, parallel: false },
  geo_api: { provider: :rambler_maps },
  enable_middlewares: true
)
config.configure(enable_middlewares: false)

# using both hash and proc (proc has higher priority)
config = Config.new(enable_middlewares: true) do |conf|
  conf.testing.parallel = true
end

config.configure(geo_api: { provider: nil }) do |conf|
  conf.testing.engine = :rspec
end
```

---

### Inheritance

```ruby
class CommonConfig < Qonfig::DataSet
  setting :uploader, :fog
end

class ProjectConfig < CommonConfig
  setting :auth_provider, :github
end

project_config = ProjectConfig.new

# inherited setting
project_config.settings.uploader # => :fog

# own setting
project_config.settings.auth_provider # => :github
```

---

### Composition

```ruby
class SharedConfig < Qonfig::DataSet
  setting :logger, Logger.new
end

class ServerConfig < Qonfig::DataSet
  setting :port, 12345
  setting :address, '0.0.0.0'
end

class DatabaseConfig < Qonfig::DataSet
  setting :user, 'test'
  setting :password, 'testpaswd'
end

class ProjectConfig < Qonfig::DataSet
  compose SharedConfig

  setting :server do
    compose ServerConfig
  end

  setting :db do
    compose DatabaseConfig
  end
end

project_config = ProjectConfig.new

# fields from SharedConfig
project_config.settings.logger # => #<Logger:0x66f57048>

# fields from ServerConfig
project_config.settings.server.port # => 12345
project_config.settings.server.address # => '0.0.0.0'

# fields from DatabaseConfig
project_config.settings.db.user # => 'test'
project_config.settings.db.password # => 'testpaswd'
```

---

### Hash representation

```ruby
class Config < Qonfig::DataSet
  setting :serializers do
    setting :json do
      setting :engine, :ok
    end

    setting :hash do
      setting :engine, :native
    end
  end

  setting :adapter do
    setting :default, :memory_sync
  end

  setting :logger, Logger.new(STDOUT)
end

Config.new.to_h

{
  "serializers": {
    "json" => { "engine" => :ok },
    "hash" => { "engine" => :native },
  },
  "adapter" => { "default" => :memory_sync },
  "logger" => #<Logger:0x4b0d79fc>
}
```

---

### Config reloading

```ruby
class Config < Qonfig::DataSet
  setting :db do
    setting :adapter, 'postgresql'
  end

  setting :logger, Logger.new(STDOUT)
end

config = Config.new

config.settings.db.adapter # => 'postgresql'
config.settings.logger # => #<Logger:0x00007ff9>

config.configure { |conf| conf.logger = nil } # redefine some settings (will be reloaded)

# re-define and append settings
class Config
  setting :db do
    setting :adapter, 'mongoid' # re-define defaults
  end

  setting :enable_api, false # append new setting
end

# reload settings
config.reload!

config.settings.db.adapter # => 'mongoid'
config.settings.logger # => #<Logger:0x00007ff9> (reloaded from defaults)
config.settings.enable_api # => false (new setting)

# reload with instant configuration
config.reload!(db: { adapter: 'oracle' }) do |conf|
  conf.enable_api = true # changed instantly
end

config.settings.db.adapter # => 'oracle'
config.settings.logger = # => #<Logger:0x00007ff9>
config.settings.enable_api # => true # value from instant change
```

---

### Clear options

```ruby
class Config
  setting :database do
    setting :user
    setting :password
  end

  setting :web_api do
    setting :endpoint
  end
end

config = Config.new do |conf|
  conf.database.user = '0exp'
  conf.database.password = 'test123'

  conf.web_api.endpoint = '/api/'
end

config.settings.database.user # => '0exp'
config.settings.database.password # => 'test123'
config.settings.web_api.endpoint # => '/api'

# clear all options
config.clear!

config.settings.database.user # => nil
config.settings.database.password # => nil
config.settings.web_api.endpoint # => nil
```

---

### State freeze

```ruby
class Config < Qonfig::DataSet
  setting :logger, Logger.new(STDOUT)
  setting :worker, :sidekiq
  setting :db do
    setting :adapter, 'postgresql'
  end
end

config = Config.new
config.freeze!

config.settings.logger = Logger.new(StringIO.new) # => Qonfig::FrozenSettingsError
config.settings.worker = :que # => Qonfig::FrozenSettingsError
config.settings.db.adapter = 'mongoid' # => Qonfig::FrozenSettingsError

config.reload! # => Qonfig::FrozenSettingsError
config.clear! # => Qonfig::FrozenSettingsError
```

---

### Settings as Predicates

- predicate form: `?` at the end of setting name;
- `nil` and `false` setting values indicates `false`;
- other setting values indicates `true`;
- setting roots always returns `true`;

```ruby
class Config < Qonfig::DataSet
  setting :database do
    setting :user
    setting :host, 'google.com'

    setting :engine do
      setting :driver, 'postgres'
    end
  end
end

config = Config.new

# predicates
config.settings.database.user? # => false (nil => false)
config.settings.database.host? # => true ('google.com' => true)
config.settings.database.engine.driver? # => true ('postgres' => true)

# setting roots always returns true
config.settings.database? # => true
config.settings.database.engine? # => ture

config.configure do |conf|
  conf.database.user = '0exp'
  conf.database.host = false
  conf.database.engine.driver = true
end

# predicates
config.settings.database.user? # => true ('0exp' => true)
config.settings.database.host? # => false (false => false)
config.settings.database.engine.driver? # => true (true => true)
```

---

### Load from YAML file

- `:strict` mode (fail behaviour when the required yaml file doesnt exist):
  - `true` (by default) - causes `Qonfig::FileNotFoundError`;
  - `false` - do nothing, ignore current command;

```yaml
<!-- travis.yml -->
sudo: false
language: ruby
rvm:
  - ruby-head
  - jruby-head
```

```yaml
<!-- project.yml -->
enable_api: false
Sidekiq/Scheduler:
  enable: true
```

```yaml
<!-- ruby_data.yml -->
version: <%= RUBY_VERSION %>
platform: <%= RUBY_PLATFORM %>
```

```ruby
class Config < Qonfig::DataSet
  setting :ruby do
    load_from_yaml 'ruby_data.yml'
  end

  setting :travis do
    load_from_yaml 'travis.yml'
  end

  load_from_yaml 'project.yml'
end

config = Config.new

config.settings.travis.sudo # => false
config.settings.travis.language # => 'ruby'
config.settings.travis.rvm # => ['ruby-head', 'jruby-head']
config.settings.enable_api # => false
config.settings['Sidekiq/Scheduler']['enable'] #=> true
config.settings.ruby.version # => '2.5.1'
config.settings.ruby.platform # => 'x86_64-darwin17'
```

```ruby
# --- strict mode ---
class Config < Qonfig::DataSet
  setting :nonexistent_yaml do
    load_from_yaml 'nonexistent_yaml.yml', strict: true # true by default
  end

  setting :another_key
end

Config.new # => Qonfig::FileNotFoundError

# --- non-strict mode ---
class Config < Qonfig::DataSet
  settings :nonexistent_yaml do
    load_from_yaml 'nonexistent_yaml.yml', strict: false
  end

  setting :another_key
end

Config.new.to_h # => { "nonexistent_yaml" => {}, "another_key" => nil }
```

---

### Load from ENV

- `:convert_values` (`false` by default):
  - `'t'`, `'T'`, `'true'`, `'TRUE'` - covnerts to `true`;
  - `'f'`, `'F'`, `'false'`, `'FALSE'` - covnerts to `false`;
  - `1`, `23` and etc - converts to `Integer`;
  - `1.25`, `0.26` and etc - converts to `Float`;
  - `1, 2, test`, `FALSE,Qonfig` (strings without quotes that contains at least one comma) -
    converts to `Array` with recursively converted values;
  - `'"please, test"'`, `"'test, please'"` (quoted strings) - converts to `String` without quotes;
- `:prefix` - load ENV variables which names starts with a prefix:
  - `nil` (by default) - empty prefix;
  - `Regexp` - names that match the regexp pattern;
  - `String` - names which starts with a passed string;
- `:trim_prefix` (`false` by default);

```ruby
# some env variables
ENV['QONFIG_BOOLEAN'] = 'true'
ENV['QONFIG_INTEGER'] = '0'
ENV['QONFIG_STRING'] = 'none'
ENV['QONFIG_ARRAY'] = '1, 2.5, t, f, TEST'
ENV['QONFIG_MESSAGE'] = '"Hello, Qonfig!"'
ENV['RUN_CI'] = '1'

class Config < Qonfig::DataSet
  # nested
  setting :qonfig do
    load_from_env convert_values: true, prefix: 'QONFIG' # or /\Aqonfig.*\z/i
  end

  setting :trimmed do
    load_from_env convert_values: true, prefix: 'QONFIG_', trim_prefix: true # trim prefix
  end

  # on the root
  load_from_env
end

config = Config.new

# customized
config.settings['qonfig']['QONFIG_BOOLEAN'] # => true ('true' => true)
config.settings['qonfig']['QONFIG_INTEGER'] # => 0 ('0' => 0)
config.settings['qonfig']['QONFIG_STRING'] # => 'none'
config.settings['qonfig']['QONFIG_ARRAY'] # => [1, 2.5, true, false, 'TEST']
config.settings['qonfig']['QONFIG_MESSAGE'] # => 'Hello, Qonfig!'
config.settings['qonfig']['RUN_CI'] # => Qonfig::UnknownSettingError

# trimmed (and customized)
config.settings['trimmed']['BOOLEAN'] # => true ('true' => true)
config.settings['trimmed']['INTEGER'] # => 0 ('0' => 0)
config.settings['trimmed']['STRING'] # => 'none'
config.settings['trimmed']['ARRAY'] # => [1, 2.5, true, false, 'TEST']
config.settings['trimmed']['MESSAGE'] # => 'Hello, Qonfig!'
config.settings['trimmed']['RUN_CI'] # => Qonfig::UnknownSettingError

# default
config.settings['QONFIG_BOOLEAN'] # => 'true'
config.settings['QONFIG_INTEGER'] # => '0'
config.settings['QONFIG_STRING'] # => 'none'
config.settings['QONFIG_ARRAY'] # => '1, 2.5, t, f, TEST'
config.settings['QONFIG_MESSAGE'] # => '"Hello, Qonfig!"'
config.settings['RUN_CI'] # => '1'
```

---

### Load from \_\_END\_\_

- aka `load_from_self`

```ruby
class Config < Qonfig::DataSet
  load_from_self # on the root

  setting :nested do
    load_from_self # nested
  end
end

config = Config.new

# on the root
config.settings.ruby_version # => '2.5.1'
config.settings.secret_key # => 'top-mega-secret'
config.settings.api_host # => 'super.puper-google.com'
config.settings.connection_timeout.seconds # => 10
config.settings.connection_timeout.enabled # => false

# nested
config.settings.nested.ruby_version # => '2.5.1'
config.settings.nested.secret_key # => 'top-mega-secret'
config.settings.nested.api_host # => 'super.puper-google.com'
config.settings.nested.connection_timeout.seconds # => 10
config.settings.nested.connection_timeout.enabled # => false

__END__

ruby_version: <%= RUBY_VERSION %>
secret_key: top-mega-secret
api_host: super.puper-google.com
connection_timeout:
  seconds: 10
  enabled: false
```

---

### Smart Mixin

- class-level:
  - `.configuration` - settings definitions;
  - `.configure` - configuration;
  - `.config` - config object;
  - settings definitions are inheritable;
- instance-level:
  - `#configure` - configuration;
  - `#config` - config object;

```ruby
# --- usage ---

class Application
  # make configurable
  include Qonfig::Configurable

  configuration do
    setting :user
    setting :password
  end
end

app = Application.new

# class-level config
Application.config.settings.user # => nil
Application.config.settings.password # => nil

# instance-level config
app.config.settings.user # => nil
app.config.settings.password # => nil

# class-level configuration
Application.configure do |conf|
  conf.user = '0exp'
  conf.password = 'test123'
end

# instance-level configuration
app.configure do |conf|
  conf.user = 'admin'
  conf.password = '123test'
end

# class has own config object
Application.config.settings.user # => '0exp'
Application.config.settings.password # => 'test123'

# instance has own config object
app.config.settings.user # => 'admin'
app.config.settings.password # => '123test'

# and etc... (all Qonfig-related features)
```

```ruby
# --- inheritance ---

class BasicApplication
  # make configurable
  include Qonfig::Configurable

  configuration do
    setting :user
    setting :pswd
  end

  configure do |conf|
    conf.user = 'admin'
    conf.pswd = 'admin'
  end
end

class GeneralApplication < BasicApplication
  # extend inherited definitions
  configuration do
    setting :db do
      setting :adapter
    end
  end

  configure do |conf|
    conf.user = '0exp' # .user inherited from BasicApplication
    conf.pswd = '123test' # .pswd inherited from BasicApplication
    conf.db.adapter = 'pg'
  end
end

BasicApplication.config.to_h
{ 'user' => 'admin', 'pswd' => 'admin' }

GeneralApplication.config.to_h
{ 'user' => '0exp', 'pswd' => '123test', 'db' => { 'adapter' => 'pg' } }

# and etc... (all Qonfig-related features)
```

---

## Contributing

- Fork it ( https://github.com/0exp/qonfig/fork )
- Create your feature branch (`git checkout -b feature/my-new-feature development`)
- Commit your changes (`git commit -am 'Add some feature'`)
- Push to the branch (`git push origin feature/my-new-feature`)
- Create new Pull Request

## License

Released under MIT License.

## Authors

[Rustam Ibragimov](https://github.com/0exp)