Module: Autocreate

Defined in:
lib/autocreate.rb

Overview

Extending a module with Autocreate allows you to specify autocreate rules for that module.

Autocreate allows you to automatically created classes or modules based on a given exemplar at the time they are referenced.

To use Autocreate, mix it via extend into the class or module within which you want to autocreate referenced constants.

See the README for an example of how to use Autocreate.

Class Method Summary collapse

Class Method Details

.extended(mod) ⇒ Object

:nodoc:



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# File 'lib/autocreate.rb', line 14

def self.extended( mod ) #:nodoc:

	old = mod.method( :const_missing )
	mod.metaclass.class_eval do

		# Specifies that the constant specified by key should be autocreated using the exemplar. If a block is given, the block is further used to initialize the block once it has been cloned.
		def autocreate( key, exemplar, &block )
			( @autocreate ||= [] ) << [ key, exemplar, block ]
			return self
		end

		define_method :const_missing do | cname | #:nodoc:

			# first, find an applicable exemplar	
			key, exemplar, block = ( @autocreate ||= [] ).find do |k,v|
				case k
					when true then true
					when String, Symbol then k.to_s == cname.to_s 
					when Array then k.find { |k| k.to_s == cname.to_s }
					else false
				end
			end

			# if we found it, set the const and return it
			if key 
				object = exemplar.clone
				( @reloadable ||= [] ) << cname; 
				const_set( cname, object )
				object.instance_eval( &block ) if block
				return object
			else
				old.call(cname)
			end

		end

	end

end