Module: ClassProp::ClassMethods

Defined in:
lib/classprop.rb

Overview

ClassMethods

Instance Method Summary collapse

Instance Method Details

#define_class_prop(prop_name, opts = {}) ⇒ Object

Defines the set and get methods for the given property.

option: init Sets the initial value of the property.

option: inherit If set to false, the property is not inherited by subclasses.

option: before_set If set, must be a Proc. The proc is called and val is set to the proc’s return value.



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# File 'lib/classprop.rb', line 57

def define_class_prop(prop_name, opts={})
	# default options
	opts = {'inherit'=>true}.merge(opts)
	
	# TESTING
	# $tm.show opts
	
	# set
	self.define_singleton_method("#{prop_name}=") do |val|
		# run before_set if necessary
		if before_set = opts['before_set']
			if not before_set.is_a?(Proc)
				raise 'before-set-not-proc'
			end
			
			val = opts['before_set'].call(val)
		end
		
		# set property
		instance_variable_set "@#{prop_name}", val
	end
	
	# get
	self.define_singleton_method(prop_name) do
		if instance_variable_defined?("@#{prop_name}")
			rv = instance_variable_get("@#{prop_name}")
			
			if rv == ClassProp::MustDefine
				raise "must-define-class-property: #{prop_name}" 
			else
				return rv
			end
		else
			if opts['inherit'] and superclass.respond_to?(prop_name)
				return superclass.public_send(prop_name)
			else
				return nil
			end
		end
	end
	
	# initial value
	if opts.has_key?('init')
		instance_variable_set "@#{prop_name}", opts['init']
	end
end

#delete_class_prop(prop_name) ⇒ Object

delete_class_prop



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# File 'lib/classprop.rb', line 105

def delete_class_prop(prop_name)
	if instance_variable_defined?("@#{prop_name}")
		remove_instance_variable "@#{prop_name}"
	end
end