Scopable

Apply or skip model scopes based on options and request parameters.

Installation

Add this line to your application's Gemfile:

gem 'scopable'

And then execute:

$ bundle

Or install it yourself with:

$ gem install scopable

Usage

Configure scopes in your controller:

class PostsController < ApplicationController
  include Scopable

  scope :search, param: :q

  # ...
end

Then apply it to your model:

def index
  @posts = scoped(Post, params)
end

Now whenever the parameter q is present in params, #search will be called on your model passing the parameter's value as argument.

Another example:

class PostController < ApplicationController
  include Scopable

  scope :by_date, param: :date do |relation, value|
    relation.where(created_at: Date.parse(value))
  end

  scope :by_author, param: :author

  scope :order, force: { created_at: :desc }

  def index
    @posts = scoped(Post, params)
  end
end

Now say your URL look like this:

/posts?date=2016-1-6&author=2

The resulting relation would be:

Post.where(created_at: '6/1/2016').by_author(2).order(created_at: :desc)

Note that order matters! The scopes will be applied in the same order they are configured.

Also note values like true/false, on/off, yes/no are treated like boolean, and when the value is evaluated to true or false the scope is called with no arguments, or skipped, respectively.

scope :active

With a URL like this:

/?active=yes

Would be equivalent to:

Model.active

Options

No option is required. By default it assumes both scope and parameter have the same name.

Key	Description
:param	Name of the parameter that activates the scope.
:default	Default value for the scope in case the parameter is missing.
:force	Force a value to the scope regardless of the request parameters.
:required	Calls #none on the model if parameter is absent and no default value is given.
:only	The scope will only be applied to these actions.
:except	The scope will be applied to all actions except these.
&block	Block will be called in the context of the action and will be given the current relation and evaluated value.

Contributing

1. Fork it ( https://github.com/[my-github-username]/scopable/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

License

See LICENSE.txt.