Thorsten Rinne - Refactoring

• Thorsten codes since 1999 (PHP 3)
• short Questionround about Companies and their Coding Behaviour
• Code ages
• Cost per Change Request are rising

• dont refactor before a important release
• you don't know how long refactoring takes
• don't refactor with a lot of Junior Developers, they need Expirience
• don't do it parallel to new features / development tasks

• use coding standard, define your own or use pear or zend
• avoid spaghetti code
• speeds up maintainability
• improves productivity
• fix your API specs
  • Listenpunkt

• what to do when refactoring
  • stay calm
  • use extreme Programming with shared pc's (one senior, one junior)
  • write Tests !!
  • don't let refactor the Devs their own Code (CodeBlindness)
  • don't let Junior Devs refactor alone
• Unit Testing
  • only with Testing you could check if you broke anything
  • Problem: most old Code is untestable
  • PartTime Solution: Selenium
  • Solution:

• Change the internal Structure without changing the external Behaviour
• Discipline: Work 8 Hours, don't do Overtime, it's hard Work
• Restructuring ?
• Don't change Behaviour
• Forms of Refactoring
• Renaming, Extraction, Changing Signatures
  • name Variables relating to the Content
  • Pull up/Pull down, don't use duplicate Methods, extract and outsource them
    • put Method you need for Child Functions to the Parent Class (Superclass)
• Tips & Tricks
  • use PHPDOCS, use PHPDOCS, use PHPDOCS
  • never use automated Refactoring
  • don't do refactoring for fun (don't let classes become to abstract)
  • write Unittest! WRITE UNITTESTS!
  • phpcpd PHP Copy&Paste Detection (Sebastian Bergmann) http://github.com/sebastianbergmann PHP CopyPaste Detection

• Discussion about Testing and Refactoring and the Importance of Teaching the Youth