# 🪄 Magic Decorator

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A bit of history:
this gem was inspired by digging deeper into [Draper](https://github.com/drapergem/draper) with an eye on a refactoring.

It implements a general decorator logic. It’s not meant to be a _presenter_.

## Installation

Install the gem and add to the application's Gemfile by executing:

    $ bundle add magic-decorator

If bundler is not being used to manage dependencies, install the gem by executing:

    $ gem install magic-decorator

## Usage

`Magic::Decorator::Base` is a basic decorator class to be inherited by any other decorator.
It further inherits from [`SimpleDelegator`](
	https://docs.ruby-lang.org/en/master/SimpleDelegator.html
) and is straightforward like that.

```ruby
class PersonDecorator < Magic::Decorator::Base
  def name = "#{first_name} #{last_name}"
end

Person = Struct.new :first_name, :last_name do
  include Magic::Decoratable
end

person = Person.new('John', 'Smith').decorate
person.name # => "John Smith"
```

### `Magic::Decoratable`

This module adds three methods to decorate an object.
Decorator class is being inferred automatically.
When no decorator is found,
* `#decorate`  returns `nil`,
* `#decorate!` raises `Magic::Lookup::Error`,
* `#decorated` returns the original object.

One can test for the object is actually decorated with `#decorated?`.

```ruby
'with no decorator for String'.decorated.decorated? # => false
['with a decorator for Array'].decorated.decorated? # => true
```

#### Magic

`Decoratable` is mixed into `Object` by default. That means that effectively any object is `Decoratable`.

### Decorator class inference

Decorators provide automatic class inference for any object based on its class name
powered by [Magic Lookup](
	https://github.com/Alexander-Senko/magic-lookup
).

For example, `MyNamespace::MyModel.new.decorate` looks for `MyNamespace::MyModelDecorator` first.
When missing, it further looks for decorators for its ancestor classes, up to `ObjectDecorator`.

## Development

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`.

## Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Alexander-Senko/magic-decorator. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [code of conduct](https://github.com/Alexander-Senko/magic-decorator/blob/main/CODE_OF_CONDUCT.md).

## License

The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).

## Code of Conduct

Everyone interacting in the Magic Decorator project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/Alexander-Senko/magic-decorator/blob/main/CODE_OF_CONDUCT.md).