Bending WordPress to your Will

This is a workshop that I presented at PHP South Africa 2017 - these slides were just the intro and the rest of the workshop was building a basic WordPress plugin.

Transcript

1. Bending WordPress
   To Your Will
   

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2. Folder Structure
   Headers
   Events
   Plugin Development
   

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3. wp-content/plugins/plugin-slug
   plugin-slug.php
   readme.txt
   Folder Structure
   

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4. Headers
   /*
   * Plugin Name: Seriously Simple Podcasting
   * Version: 1.9.6
   * Plugin URI: https://wordpress.org/plugins/seriously-simple-podcasting/
   * Description: Podcasting the way it's meant to be.
   * Author: Hugh Lashbrooke
   * Author URI: http://www.hughlashbrooke.com/
   * Requires at least: 4.0
   * Tested up to: 4.2
   *
   * Text Domain: seriously-simple-podcasting
   * Domain Path: /lang/
   */
   

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5. PHP
   call_user_func()
   WordPress
   do_action()
   apply_filters()
   Events
   

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6. do_action( ‘hook’ );
   add_action( ‘hook’, ‘my_function’ );
   Events: Hooks
   

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7. add_action( ‘init’, ‘init_function’ );
   function init_function() {
   ...
   }
   Events: Hooks
   

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8. add_action( ‘hook’, ‘my_function’, 10 );
   Lower number == higher priority
   Events: Priorities
   

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9. add_action( ‘hook’, ‘my_function’, 10, 2 );
   function my_function ( $foo, $bar ) {
   ...
   }
   Events: Parameters
   

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10. apply_filters( ‘filter’, $foo );
    add_filter( ‘filter’, ‘my_function’ );
    Filters must always return a value
    Events: Filters
    

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11. add_filter( ‘body_class’, ‘my_function’ );
    function my_function( $classes ) {
    $classes[] = ‘my-class’;
    return $classes;
    }
    Events: Filters
    

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12. remove_action( ‘hook’, ‘function’ );
    remove_filter( ‘filter’, ‘function’ );
    Priorities must match original hook/filter
    Removing Hooks & Filters
    

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13. /*
    * Plugin Name: Google Redirect
    * Version: 1.0
    */
    add_action( ‘init’, ‘google_redirect’ );
    function google_redirect () {
    if( isset( $_GET[‘google_redirect’] ) ) {
    wp_redirect( ‘http://www.google.com’, 302 );
    exit;
    }
    }
    ?>
    Bringing it Together
    

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14. Plugin Developer Info: wordpress.org/plugins/developers/
    Coding Standards: codex.wordpress.org/WordPress_Coding_Standards
    Action Reference: codex.wordpress.org/Plugin_API/Action_Reference
    Plugin Template: github.com/hlashbrooke/WordPress-Plugin-Template
    Helpful Links
    

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15. https://github.com/hlashbrooke/Post-View-Counter
    Demo Plugin
    

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16. automattic.com
    make.wordpress.org
    hugh.blog
    @hlashbrooke
    

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