decorator

# Decorator

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A simple [Crystal](https://crystal-lang.org) shard for decorating objects.

## Installation

Add the dependency to your `shard.yml`:

```yaml
dependencies:
  decorator:
    github: stephendolan/decorator
```

Run `shards install`

## 🎬 Screencast

<a href="https://luckycasts.com/videos/decorator-shard"><img src="https://i.imgur.com/1gs4z0c.jpg" title="Decorating Lucky Apps with the Decorator Shard" width="500" /></a>

[Watch a LuckyCast on the Decorator shard](https://luckycasts.com/videos/decorator-shard)

## Usage

Require the shard:

```crystal
require "decorator"
```

Create a decorator `Struct` that inherits from `Decorator::Base`, and define
what it `decorates`:

```crystal
struct TimeDecorator < Decorator::Base
  decorates time : Time

  # Return a pretty version of a date and weekday in the format:
  # `Monday, November 2, 2020`
  def date_with_weekday : String
    time.to_s("%A, %B %-d, %Y")
  end

  # Return a pretty version of a date in the format:
  # `November 2, 2020`
  def date : String
    time.to_s("%B %-d, %Y")
  end
end
```

In the above example, `Decorator` adds the following to the `TimeDecorator`
struct for you:

- An `initialize(@time : Time)` method
- A `collection(objects : Array(Time))` class method
- A `getter` (or `getter?` for `Bool` types) for `@time`

Now, you're able to transform `Time` objects using the decorator:

```crystal
decorated_time = TimeDecorator.new(Time.utc)

puts decorated_time.date_with_weekday
# => "Monday, November 2, 2020"

puts decorated_time.date
# => "November 2, 2020"
```

Or even a collection of time objects with the `collection` method:

```crystal
decorated_times = TimeDecorator.collection([
  Time.utc - 1.year,
  Time.utc,
  Time.utc + 1.year
])

puts decorated_times[0].date_with_weekday
# => "Saturday, November 2, 2019"
puts decorated_times[1].date_with_weekday
# => "Monday, November 2, 2020"
puts decorated_times[2].date_with_weekday
# => "Tuesday, November 2, 2021"
```

## Contributing

1. [Fork it](https://github.com/stephendolan/decorator/fork)
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 a new Pull Request

## Contributors

- [Stephen Dolan](https://github.com/stephendolan) - creator and maintainer

## Inspiration

- The `decorates` syntax and code mimics the [Lucky::Assignable Module](https://github.com/luckyframework/lucky/blob/master/src/lucky/assignable.cr) `needs` implementation created by the [Lucky](https://luckyframework.org) team.