ForwardingDsl

ForwardingDsl makes it easy to build user friendly DSLs. While ForwardingDsl.run will allow you to create a DSL from a regular object, ForwardingDsl::Getsetter will make easy to declare attributes for it. It is inspired by the blog post instance_eval with access to outside scope.

Benefits:

• Makes it trivial to provide a DSL. Wrap anything with ForwardingDsl.run() and you are done.
• Unlike instance_eval, only the public API of your object is reachable from the DSL.
• Unlike instance_eval, methods available outside of the DSL are still available inside.
• Compatible with the explicit yield(self), no DSL, style.

Wrap any object to make a DSL out of it:

require 'forwarding_dsl'

App = Struct.new(:host, :port)
app = App.new("localhost", 80)

ForwardingDsl.run app do
  host
end
# => "localhost"

Use ForwardingDsl::Getsetter to declare attributes that receive values on a declarative way:

class MyApp
  include ForwardingDsl::Getsetter

  getsetter :host, :port

  def initialize &block
    ForwardingDsl.run(my_object, &block)
  end
end

app = MyApp.new do
  host 'localhost'
  port 80
end

app.host # => 'localhost'
app.port # => 80

ForwardingDsl is also compatible with the classic yield(self). The context of the block will remain untouched in that case:

app = MyApp.new do |a|
  a.host 'localhost'
  a.port = 80
end

Methods available outside of the DSL block are also available inside:

def port_configuration
  configuration[:port]
end

app = MyApp.new do
  port port_configuration
end

If needed, the yielded object is available explicitly through this and the outer context through that:

def port_configuration
  configuration[:port]
end

app = MyApp.new do
  this.port = that.port_configuration
end

Do not forget to run the tests with:

rake

And bump the version with any of:

$ gem bump --version 1.1.1       # Bump the gem version to the given version number
$ gem bump --version major       # Bump the gem version to the next major level (e.g. 0.0.1 to 1.0.0)
$ gem bump --version minor       # Bump the gem version to the next minor level (e.g. 0.0.1 to 0.1.0)
$ gem bump --version patch       # Bump the gem version to the next patch level (e.g. 0.0.1 to 0.0.2)

Released under the MIT License. See the LICENSE file for further details.