Chris Scott - @chrisscott - slideshare.net/iamzedphoto by mimk http://www.flickr.com/photos/mimk/222612527/

YOU’RE DOING IT WRONG

Thanks• Dion Hulse’s (DD32) two part series on doing it

wrong:• http://dd32.id.au/2009/11/01/youre-doing-it-

wrong-1/• http://dd32.id.au/2009/11/01/youre-doing-it-

wrong-2/• http://dd32.id.au/2009/11/24/how-to-do-it-right-

part-0/• Michael Pretty for ideas and telling me what I’m doing

wrong• Sean O’Shaughnessy for ideas and graphics

New Features in a Year:2.7 - 2.8.6

• Sticky posts• Comment threading and paging• Widgets API• Load scripts minified by default• Load scripts in the footer• esc_* functions• security fixes• and much more...

Wrong and Right

Not Upgrading

WRONG

Upgrading

RIGHT

Calling Functions That Don’t Exist

<div id="sidebar" role="complementary"> <ul> <li><?php wp_ozh_wsa('mybanner') ?></li>

... rest of sidebar ...

</ul></div>

WRONG

Check for Functions Before Calling

<div id="sidebar" role="complementary"> <ul> <?php if (function_exists('wp_ozh_wsa')) : ?> <li><?php wp_ozh_wsa('mybanner') ?></li> <?php endif; ?> ... rest of sidebar ...

</ul></div>

RIGHT

Hard-Coding WordPress Paths

$cb_path = get_bloginfo('wpurl')."/wp-content/plugins/wp-codebox"; //URL to the plugin directory

WRONG

Use Constants or Helper Functions

$cb_path = plugins_url('', __FILE__); //URL to the plugin directory

RIGHT

Echoing Scripts/CSS in Header/Footer

function codebox_header() { $hHead .= "<script language=\"javascript\" type=\"text/javascript\" src=\"".get_bloginfo('wpurl')."/wp-includes/js/jquery/jquery.js\"></script>\n"; $hHead .= "<script language=\"javascript\" type=\"text/javascript\" src=\"{$cb_path}/js/codebox.js\" ></script>\n"; print($hHead);}add_action('wp_head', 'codebox_header');

WRONG

Enqueue Scripts and Styles

function codebox_header() { wp_enqueue_script( 'codebox', plugins_url('js/ codebox.js', __FILE__), array('jquery') );}add_action('template_redirect', 'codebox_header');

RIGHT

Not Checking Indices or Object Properties

if ($_GET['wp125action'] == "deactivate") { ...}

WRONG

Checking Indices/Properties

if (isset($_GET['wp125action']) && $_GET['wp125action'] == "deactivate") { ...}

RIGHT

Not Using WP_DEBUG

WRONG

Define WP_DEBUG in wp-config.php

RIGHT

define('WP_DEBUG', true);

Using Globals Instead of Helper Functions/Classes

global $post;

$linkname = get_the_title($post->ID);

WRONG

Use Helper Functions/Classes

$linkname = get_the_title();

RIGHT

Writing SQL

global $wpdb;

$wpdb->query("update ".$articles." set review = ". $rating." where post_id = ".$post_id);

WRONG

Use $wpdb Methods

global $wpdb;

$wpdb->update( $articles, array('review' => $rating), compact('post_id'));

RIGHT

Not Validating/Escaping User Input

<label for="title"><?php echo get_option('my_plugin_option_title'); ?></label>

<input type="text" id="value" name="value" value="<?php echo get_option('my_plugin_option_value')); ?>">

WRONG

Validate and Escape User Input

<label for="title"><?php echo esc_html(get_option('my_plugin_option_title')); ?></label>

<input type="text" id="value" name="value" value="<?php echo esc_attr(get_option('my_plugin_option_value')); ?>">

RIGHT

Not Using Caching

$response = wp_remote_get($url);if (!is_wp_error($response) && $response['response']['code'] == '200') { $data = $response['body'];}... do something with data ...

WRONG

Use Caching

if (!$data = wp_cache_get('my_external_data')) { $response = wp_remote_get($url); if (!is_wp_error($response) && $response['response']['code'] == '200') { $data = $response['body']; wp_cache_set('my_external_data', $data); }}... do something with data ...

RIGHT

Not Contributing

WRONG

photo by TaranRampersad http://www.flickr.com/photos/knowprose/2294744043/

Contributing

RIGHT

http://codex.wordpress.org/Contributing_to_WordPress

• Edit the Codex• Answer Forum Support Questions• Participate in Development

• Planning, Testing, Bug Reporting and Fixing• Say “Thanks”