Namespaces and Autoloading: Improving WordPress Plugin Architecture

Transcript

1. NAMESPACES AND AUTOLOADING Tom McFarlin | https://tommcfarlin.com | @tommcfarlin WordCamp

   Atlanta 2017

2. HEY, WHAT’S UP? • I’m Tom (Nice to meet you)

   • Suburbia Atlanta • Pressware • Life Outside WordPress

3. BUT ENOUGH ABOUT ME Let’s talk about you and code

   and your code.

4. YOUR CODE • Namespaces • Autoloading • …Boring!

5. BUT ARE THEY REALLY? They sound boring.

6. THEY AREN’T BORING • Improved Code • Better Organization •

   Increased Maintainability • Easier Debugging • More Money! (Maybe.) “Boring conversation anyway.”

7. WHAT ARE THEY? Oh! Money? (Not so boring anymore!)

8. WHAT ARE THEY? • Plugin conflicts • Weird warning messages

   • Unable to activate a plugin • `class_exists` Namespaces

9. WHAT ARE THEY? • `include` • `include_once` • `require` •

   `require_once` Autoloaders

10. NAMESPACES

11. The PHP Manual http://php.net/manual/en/language.namespaces.rationale.php “Namespaces are designed to solve two

    problems that authors of libraries and applications encounter when creating re-usable code elements such as classes or functions…”

12. “A way to group related classes and interfaces having a

    similar purpose.” WordCamp Atlanta 2017 A Working Definition

13. A PRACTICAL EXAMPLE • You’re working with files. • Classes

    for reading, • Classes for writing, • You may have interfaces, • And so on.
14. None
15. None

16. NAMESPACE THAT CODE!

17. None
18. None

19. ON FILE ORGANIZATION • It’s not required; it helps. •

    Logical Organization • Virtual Organization • Aim For Both. Please.
20. None
21. None

22. LET’S INSTANTIATE THEM! Wait, How?

23. NOTES ON NAMESPACES • You can’t just use `new.` •

    Use the fully-qualified name. (The what?)
24. None
25. None

26. NOTES ON NAMESPACES • Aliasing with `use` • Place under

    `namespace` • Now use the alias.

27. NOW LET’S INSTANTIATE THEM! That’s, How!

28. None

29. AUTOLOADING

30. The PHP Manual http://php.net/manual/en/language.oop5.autoload.php “The spl_autoload_register() function registers any number

    of autoloaders, enabling for classes and interfaces to be automatically loaded if they are currently not defined. By registering autoloaders, PHP is given a last chance to load the class or interface before it fails with an error.”

31. “A way to automatically load interfaces and classes without using

    include and require statements.” WordCamp Atlanta 2017 A Working Definition

32. A PRACTICAL EXAMPLE • Your files are organized. • You’re

    ready to load them. • Let’s do it automatically! • Autoloading, right?

33. LET’S INSTANTIATE THEM! Wait, How?

34. WRITING AN AUTOLOADER • It’s not fully automated. • We

    have to write it. • But once done, it’s done. • It can be reused!

35. ON AUTOLOADING • Where are the files? • How are

    the files named? • Check if the file exists.
36. None
37. None

38. ON AUTOLOADING • Procedural • Object-oriented • `spl_autoload_register()`

39. STEPS FOR AN AUTOLOADER 1. Look at the argument 2.

    Parse the namespace(s) 3. Is it an interface or a class? 4. Does the file exist? 5. Include the file.

40. WHERE TO FIND MORE • My Website • https://tommcfarlin.com •

    SpeakerDeck • https://speakerdeck.com/tommcfarlin • GitHub • https://github.com/tommcfarlin

41. THANK YOU! Questions? Tom McFarlin | https://tommcfarlin.com | @tommcfarlin WordCamp

    Atlanta 2017