PHP for WordPress

Slides for a talk at WordCamp Baltimore 2015 about what to know about PHP when starting off with WordPress Development as well as where you can learn all of this.

Transcript

1. PHP for WordPress
   Zac Gordon
   @zgordon
   

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2. What is PHP?
   

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3. Many Developers
   Learn PHP via WP
   

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4. Often Starts with
   Theme Customization
   

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5. Some Examples of
   PHP Theme Customization
   

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6. What to Know
   Before Learning PHP
   

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7. What to Know 

   About PHP for WordPress
   

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8. • Language Basics
   • WP Coding Standards
   • Common Files
   • The Loop
   • Template Tags
   • Conditionals
   • Hooks
   What to Know About

   PHP for WordPress
   

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9. • Syntax
   • Variables
   • Operators
   • Conditionals
   • Loops
   • Functions
   • Objects
   PHP Language Basics
   

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10. Learn PHP Basics

    In 4 Hours at CodeAcademy
    For Free codecademy.com
    

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11. Learn PHP
    In 4 Hours on CodeAcademy
    For Free!!!
    

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12. Ways of Writing PHP
    in WordPress Files
    

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13. if ( is_front_page() ) {
    echo “Welcome Home!”;
    }
    ?>
    HTML in PHP
    example-1.php
    

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14. ”>
    
    
    PHP in HTML
    example-2.php
    

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15. • Syntax
    • Variables
    • Operators
    • Conditionals
    • Loops
    • Functions
    • Objects
    PHP Language Basics
    

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16. Learn PHP Basics

    In 4 Hours at CodeAcademy
    For Free codecademy.com
    

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17. WordPress has PHP
    Coding Standards
    https://make.wordpress.org/core/handbook/best-practices/coding-standards/php/
    

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18. function myCustomFunction() {}
    function my_custom_function() {}
    WordPress has PHP
    Coding Standards
    if(is_single()):
    if ( is_single() ) :
    the_title(‘h2’,’h3’)
    the_title( ‘h2’, ‘h2’ )
    

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19. Common PHP
    Theme Files
    

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20. • header.php
    • footer.php
    • functions.php
    • page.php, single.php
    • front-page.php, home.php
    • category.php, archive.php
    Common Theme Files
    

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21. Template Hierarchy
    http://wphierarchy.com/
    

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22. Archives
    Custom Posts

    Miscellaneous
    Hierarchy Review
    How They Work
    Core Files

    Homepages
    Pages and Posts
    Template Hierarchy Course
    at Treehouse
    http://teamtreehouse.com/library/the-wordpress-template-hierarchy
    

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23. Why Learn
    The Loop?
    

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24. 
    
    
    
    Oh No!!!
    There is no content for this page
    
    The Loop
    

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25. $args = array(
    'post_type' => ‘portfolio’,
    ‘category_name’ => ‘featured’,
    ‘posts_per_page’ => 4
    );
    $query = new WP_Query( $args );
    ?>
    Custom Loops with WP_Query
    have_posts() ) : while( $query->have_posts() ) :
    $query->the_post(); ?>
    
    
    
    

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26. 
    
    
    Including Files
    

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27. Including Files
    get_template_part( 'content', 'page' );
    Loads: content-page.php
    get_template_part( 'custom' );
    Loads: custom.php
    get_template_part( ‘lib/my’ ‘file’ );
    Loads: /lib/my-file.php
    

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28. • Language Basics
    • WP Coding Standards
    • Common Files
    • The Loop
    • Template Tags
    • Conditionals
    • Hooks
    What to Know About

    PHP for WordPress
    

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29. Template Tags
    Get You What You Need
    

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30. • the_title()
    • the_content()
    • the_author()
    • the_category()
    • the_time()
    Examples of
    Template Tags
    https://codex.wordpress.org/Template_Tags
    

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31. the_time( 'F j, Y' );
    September 12, 2015
    Some Template Tags
    Take Parameters
    https://codex.wordpress.org/Function_Reference/the_time
    the_time( ‘n/j/y’ );
    09/12/15
    the_time( ‘l g:i a’ );
    Saturday 9:00 am
    

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32. Template Tag
    Documentation
    

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33. One More
    bloginfo()
    

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34. bloginfo( 'name' );
    Site Name
    Get Information
    About WordPress Install
    https://codex.wordpress.org/Function_Reference/bloginfo
    bloginfo( ‘description’ );
    Site Description
    bloginfo( ‘url’ );
    http://siteurl.com
    

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35. https://codex.wordpress.org/
    Template_Tags
    

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36. • Language Basics
    • WP Coding Standards
    • Common Files
    • The Loop
    • Template Tags
    • Conditionals
    • Hooks
    What to Know About

    PHP for WordPress
    

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37. 
    Welcome Home!
    
    Conditional Statements
    https://codex.wordpress.org/Conditional_Tags
    

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38. if ( is_front_page() ) {
    echo “Welcome Home!”;
    }
    ?>
    Conditional Statements
    https://codex.wordpress.org/Conditional_Tags
    

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39. • is_page(), is_page( ‘about‘ )
    • is_category()
    • is_author()
    • wp_is_mobile()
    • is_main_query()
    • is_woocommerce()
    • is_shop(), is_cart()
    Conditional Statements
    https://codex.wordpress.org/Conditional_Tags
    

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40. Can Also Do Not
    !is_single()
    

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41. if ( is_front_page() ) {
    } elseif ( is_page( ‘about’ ) {
    } else {
    }
    Multiple Conditions
    

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42. function get_the_archive_title() {
    if ( is_category() ) {
    $title = sprintf( __( 'Category: %s' ),
    single_cat_title( '', false ) );
    } elseif ( is_tag() ) {
    $title = sprintf( __( 'Tag: %s' ),
    single_tag_title( '', false ) );
    } elseif ( is_author() ) {
    $title = sprintf( __( 'Author: %s' ), 'class="vcard">' . get_the_author() . '' );
    } elseif ( is_year() ) {
    $title = sprintf( __( 'Year: %s' ),
    get_the_date( _x( 'Y', 'yearly archives date
    format' ) ) );
    } elseif ( is_month() ) {
    

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43. • Language Basics
    • WP Coding Standards
    • Common Files
    • The Loop
    • Template Tags
    • Conditionals
    • Hooks
    What to Know About

    PHP for WordPress
    

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44. Hooks Let You Do
    Anything, Anywhere, Anytime
    In WordPress
    

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45. Filters vs Actions
    

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46. “Anything, Anywhere, Anytime”
    Filters
    }
    

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47. “Anything, Anywhere, Anytime”
    Actions
    }
    

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48. Filters modify something
    

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49. Actions do something
    

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50. A Few Examples of
    Actions and Filters
    

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51. function excerpt_length_example( $length ) {
    return 15;
    }
    add_filter( 'excerpt_length', 'excerpt_length_example' );
    

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52. function body_class_example( $classes ) {
    if( is_single() ) {
    foreach( get_the_category( get_the_ID() ) as $cat )
    $classes[] = 'cat-' . $cat->category_nicename;
    }
    return $classes;
    }
    add_filter( 'body_class', 'body_class_example' );
    

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53. function register_my_menus() {
    register_nav_menus(
    array(
    'footer_menu' => __( 'Footer Menu', 'mytheme' )
    )
    );
    }
    add_action( 'init', 'register_my_menus' );
    

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54. function my_plugin_page() {
    add_options_page(
    'Page Title',
    ‘Menu Title',
    'manage_options',
    ‘plugin-slug',
    ‘my_plugin_page_init’ );
    }
    add_action( 'admin_menu' , 'my_plugin_page' );
    

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55. function publish_post_to_slack( ) {
    // Connect to Slack API
    }
    add_action( 'save_post', ‘publish_post_to_slack’ );
    

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56. http://codex.wordpress.org/Plugin_API/Filter_Reference
    http://codex.wordpress.org/Plugin_API/Action_Reference
    

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57. http://codex.wordpress.org/Plugin_API/Action_Reference
    Runtime
    

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58. Where to Learn
    All of This, Again
    

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59. Language Basics
    CodeAcademy
    

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60. WP Coding Standards
    make.wordpress.org
    

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61. Common Files
    wphierarchy.com
    

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62. The Loop
    codex.wordpress.org/The_Loop
    

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63. Template Tags
    codex.wordpress.org/Template_Tags
    

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64. Conditional Tags
    codex.wordpress.org/Conditional_Tags
    

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65. Hooks
    Treehouse Hooks Course
    

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66. Be Practical
    In Your Learning
    

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67. Zac Gordon
    wp.zacgordon.com
    @zgordon
    https://teamtreehouse.com/learn/wordpress
    

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