# MuchPlugin

An API to ensure mixin included logic (the "plugin") only runs once.

## Usage

```ruby
requre "much-plugin"

module MyPluginMixin
  include MuchPlugin

  plugin_included do
    # do some stuff ...
    # - will be class eval'd in the scope of the receiver of `MyPluginMixin`
    # - will only be executed once per receiver, no matter how many times
    #   `MyPluginMixin` is included in that receiver
  end
end
```

Mix `MuchPlugin` in on other mixins that act as "plugins" to other components.  Define included hooks using `plugin_included` that will be class eval'd in the scope of the receiver.

This allows you to define multiple hooks separately and ensures each hook will only be executed once - even if your plugin is mixed in multiple times on the same receiver.

### `plugin_class_methods` / `plugin_instance_methods`

MuchPlugin provides convenience methods for defining instance/class methods on plugin receivers:

```ruby
requre "much-plugin"

module MyPluginMixin
  include MuchPlugin

  plugin_class_methods do
    # define some methods ...
    # - these methods will become class methods on the receiver
  end

  plugin_instance_methods do
    # define some methods ...
    # - these methods will become instance methods on the receiver
  end
end
```

### `after_plugin_included`

These hooks work just like the `plugin_included` hooks, except they are evaluated _after_ any plugin class/instance methods have been evaluated. E.g. use this to call a class method that the plugin defines.

```ruby
requre "much-plugin"

module MyPluginMixin
  include MuchPlugin

  after_plugin_included do
    configure_the_plugin
  end

  plugin_class_methods do
    def configure_the_plugin
      # ...
    end
  end
end
```

## Example

```ruby
requre "much-plugin"

module AnotherMixin
  def another
    "another"
  end
end

module MyPlugin
  include MuchPlugin

  plugin_included do
    include AnotherMixin
  end

  plugin_class_methods do
    def a_class_method
      "a-class-method"
    end
  end

  plugin_instance_methods do
    def an_instance_method
      "an-instance-method"
    end
  end
end

class MyClass
  include MyPlugin
end

my_class = MyClass.new
my_class.another            # => "another"
my_class.an_instance_method # => "an-instance-method"
MyClass.a_class_method      # => "a-class-method"
```

## Installation

Add this line to your application's Gemfile:

    gem "much-plugin"

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install much-plugin

## Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Added some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request