SmartProperties

Ruby accessors on steroids – http://github.com/t6d/smart_properties

Transcript

1. Konstantin Tennhard Ruby developer at flinc.org Hi, I'm … @t6d github.com/t6d me@t6d.de
2. Accessors & Plain-old Ruby classes … and I'll talk about
3. class Message attr_reader :subject def initialize(attrs = {}) self.subject = attrs[:subject] end def subject=(value) unless value raise ArgumentError, "No subject given" end value = value.to_s if value.length < 3 raise ArgumentError, "Invalid subject" end @subject = value end end attr_accessor •Doesn't always do the job •No conversion •No validation •No support for default values •No support for not-nil constraint •Results in tedious work you have to do OVER AND OVER again
4. What can we do? How can we DRY this out?
5. SmartProperties Slim, DRY, and easy to use …
6. require 'smart_properties' class Message include SmartProperties property :subject, :required => true, :converts => :to_s, :accepts => lambda { |s| s.length >= 3 } end SmartProperties •Features •Conversion •Validation •Default values •Not-nil constraint •Simple Interface
7. require 'smart_properties' class Message include SmartProperties property :subject, :required => true, :converts => :to_s, :accepts => lambda { |s| s.length >= 3 } def subject subject = super # do something amazing … end end SmartProperties •Advanced features •Overriding methods
8. SmartProperties github.com/t6d/smart_properties
9. Thanks! Are there any questions?