Namespaces and Autoloading: Improving WordPress Plugin Architecture

How to use namespaces and autoloading to improve your WordPress plugin architecture.

Transcript

1. NAMESPACES AND AUTOLOADING
   Tom McFarlin | https://tommcfarlin.com | @tommcfarlin
   WordCamp Atlanta 2017
   

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2. HEY, WHAT’S UP?
   • I’m Tom (Nice to meet you)
   • Suburbia Atlanta
   • Pressware
   • Life Outside WordPress
   

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

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

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5. BUT ARE THEY REALLY?
   They sound boring.
   

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6. THEY AREN’T BORING
   • Improved Code
   • Better Organization
   • Increased Maintainability
   • Easier Debugging
   • More Money! (Maybe.)
   “Boring conversation anyway.”
   

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

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8. WHAT ARE THEY?
   • Plugin conflicts
   • Weird warning messages
   • Unable to activate a plugin
   • `class_exists`
   Namespaces
   

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

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10. NAMESPACES
    

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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…”
    

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12. “A way to group related classes and interfaces
    having a similar purpose.”
    WordCamp Atlanta 2017
    A Working Definition
    

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13. A PRACTICAL EXAMPLE
    • You’re working with files.
    • Classes for reading,
    • Classes for writing,
    • You may have interfaces,
    • And so on.
    

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16. NAMESPACE THAT CODE!
    

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19. ON FILE ORGANIZATION
    • It’s not required; it helps.
    • Logical Organization
    • Virtual Organization
    • Aim For Both. Please.
    

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

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23. NOTES ON NAMESPACES
    • You can’t just use `new.`
    • Use the fully-qualified name.
    (The what?)
    

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26. NOTES ON NAMESPACES
    • Aliasing with `use`
    • Place under `namespace`
    • Now use the alias.
    

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

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29. AUTOLOADING
    

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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.”
    

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31. “A way to automatically load interfaces and classes
    without using include and require statements.”
    WordCamp Atlanta 2017
    A Working Definition
    

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32. A PRACTICAL EXAMPLE
    • Your files are organized.
    • You’re ready to load them.
    • Let’s do it automatically!
    • Autoloading, right?
    

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

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34. WRITING AN AUTOLOADER
    • It’s not fully automated.
    • We have to write it.
    • But once done, it’s done.
    • It can be reused!
    

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35. ON AUTOLOADING
    • Where are the files?
    • How are the files named?
    • Check if the file exists.
    

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

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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.
    

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40. WHERE TO FIND MORE
    • My Website
    • https://tommcfarlin.com
    • SpeakerDeck
    • https://speakerdeck.com/tommcfarlin
    • GitHub
    • https://github.com/tommcfarlin
    

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41. THANK YOU!
    Questions?
    Tom McFarlin | https://tommcfarlin.com | @tommcfarlin
    WordCamp Atlanta 2017
    

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