WordCamp Portland 2018: PHP for WordPress

for
Speaking the language of WordPress
2018

Alena Holligan
PHP Teacher at Treehouse
PHPDX User Group Leader
Web Developer for 20 years
https://github.com/sketchings/
wp-random-quote-playground

PART 1: Basics of PHP
Variables
Conditionals
Functions

PART 2: Build A Plugin
Minimum Viable Plugin (MVP)
Interacting with WordPress
Adding a Shortcode

Cany Arrays
$mm1 = [
'orange','orange','orange','red','yellow','yellow',
'yellow','green', 'green', 'green', 'blue', 'blue'
];
var_dump(array_count_values($mm1));
$mm2 = [
'yellow', 'green', 'green', 'green', 'blue', 'blue',
'orange', 'orange', 'orange', 'red', 'red', 'blue'
];
$bag = [$mm1, $mm2];

Variables: scalar (boolean, integer, float,
string)
$workday = false; // boolean
$hour = 6; // integer
$price = 15.25; // float
$quote = "Your future is created by what you do today,"
. " not tomorrow."; // string
$quote .= " — Robert Kiyosaki"; // concatenation
define( 'FORCE_SSL_ADMIN', true); // doesn’t change

PHP Basics
<?php
/*
Multi Line Comment
Used for documentation
*/
$total = (6*3) + (12/4) - 2.5;// math 18.5
echo "This will display $total value on page.";// 18.5
echo 'This will display $total name on page.';// $total
var_dump($total, FORCE_SSL_ADMIN);
// float(18.5) bool(true)
// leave off the closing tag if ending a file
?>

Variables: array
$motivation = array(
"You don’t have to be great to start...",
"Set a goal that makes you want to jump...",
"You’ll never change your life until...",
"This is not just another day, this is...",
"Leave your ego at the door every morning...",
);
$motivation[] = $quote;
echo $motivation[0];

Functions: Build-In
string substr — Return part of a string
int strlen — Get string length
string trim — Strip whitespace (or other characters) from the beginning
and end of a string (also rtrim & ltrim)
int strpos — Find position of first occurrence of substring in string
string strtolower — Make a string lowercase (also strtoupper)
mixed str_replace — Replace all occurrences of the search string with
the replacement string
Array Functions
array array_merge — Merge one or more arrays
bool in_array — Checks if a value exists in an array
array array_keys — Return all the keys (or subset) of an array

Functions: User Defined
function sketchings_quotes ( $category = null )
{
$motivation = array(...);
$encouragement = array(...);
if ( in_array(strtolower(trim($category)),
array('motivation', 'motivated', 'motivate')) ) {
return $motivation;
}
if ( in_array(strtolower(trim($category)),
array('encouragement','encourage','encouraging')) ) {
return $encouragement;
}
return array_merge($motivation, $encouragement);
}

Conditionals
function sketchings_random_quote ( $category = null )
{
$hour = date('H');
if (!empty($category)) {
$quotes = sketchings_quotes($category);
} elseif ($hour > 4 && $hour < 17) {
$quotes = sketchings_quotes('motivation');
} else {
$quotes = sketchings_quotes('encouragement');
}
$index = array_rand($quotes);
return $quotes[$index];
}

Loops
for − loops through a block of code a specified number of times.
while − loops through a block of code if and as long as a specified condition is
true.
do...while − loops through a block of code once, and then repeats the loop as
long as a special condition is true.
foreach − loops through a block of code for each element in an array.

Loops: foreach
function sketchings_tooltip($content) {
$search = array(' motivation',' encouragement', '...');
foreach ($search as $word) {
$content = str_ireplace(
$word,
' ' . $word
. ''
. sketchings_random_quote($word)
. '',
$content
);
}
return $content;
}

Minimum Viable Plugin (MVP)
File: sketchings-random-quote-playground.php
<?php
/*
Plugin Name: WP Random Quote Playground
*/

Interacting with WordPress
Themes Look and feel of the site
Plugins Added functionality of the site
Hooks Themes and Plugins “Hook” into Core using “Actions” and “Filters”
Actions Add or Remove Functionality
Filters Change Data

Actions: Add or Remove Functionality
function sketchings_random_quote_styles() {
wp_register_style(
'quote-styles',
plugin_dir_url( __FILE__ ) . 'css/styles.css'
);
wp_enqueue_style( 'quote-styles' );
}
add_action( 'wp_head', 'sketchings_random_quote_styles' );

Filters: Change Data
function sketchings_tooltip($content) {
$search = array(' motivation',' encouragement', '...');
foreach ($search as $word) {
$content = str_ireplace(
$word,
' ' . trim($word)
. ''
. sketchings_random_quote($word)
. '',
$content
);
}
return $content;
}
add_filter ('the_content', 'sketchings_tooltip');

Shortcode: Add to post or widgets
function sketchings_random_quote_shortcode( $atts ) {
return sketchings_random_quote( $atts['category'] );
}
add_shortcode(
'random-quote',
'Sketchings_random_quote_shortcode'
);
// to use in page or widget
[random-quote category = "motivation"]

Resources
PHP
DOCS: php.net
phptherightway.com
teamtreehouse.com
Local Server: MAMP
WordPress
DOCS: codex.wordpress.org
wpmudev.org
wpshout.com
SmashingMagazine.com

Where to find Alena:
TeamTreehouse.com
Meetup.com: PDX-PHP
Sketchings.com
Twitter: @sketchings
GitHub: sketchings
https://github.com/sketchings/wp-random-quote-playground

WordCamp Portland 2018: PHP for WordPress

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