Highly Useful WordPress Code Snippets

Code snippets are a great way to add extra functionality to your WordPress site without the need to download and install a plugin. In this post we will outline some highly useful code snippets.

Keep all your code snippets organized

The first tip in regards to code snippets is to keep them organized and in a central location that is easy for you to manage.

Some developers may tend to stay away from code snippets as they can be quite messy and mundane to manage. Typically you paste the code snippet with the function that you want to add in your theme’s ‘functions.php’ file. If this is the case, you should be happy to know that there is a plugin available to help you manage all of your WordPress code snippets.

Code Snippets Plugin

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Code Snippets Plugin

The best plugin to manage these code snippets is called Code Snippets and can be downloaded from the WordPress plugin repository. Code Snippets is an easy, clean and simple way to add code snippets to your site. No need to edit to your theme’s functions.php file again!

Add a Favicon

Although there are plugins available, adding a favicon to your WordPress site really doesn’t require a plugin. Instead, just use this extremely simple code snippet:

add_action( 'wp_head', 'my_favicon');
function my_favicon(){
	echo "<link href="" . get_stylesheet_directory_uri() . "/favicon.ico" rel="shortcut icon" />" . "\n";
}

Place WordPress in Maintenance Mode

There may be times when you are working on your site doing updates and you wish to place your site into maintenance mode. This can be done with this code snippet:

function maintenace_mode() {
    if ( !current_user_can( 'edit_themes' ) || !is_user_logged_in() ) {
        die('YOUR MESSAGE');
    }
}
add_action('get_header', 'maintenace_mode');

Replace ‘YOUR MESSAGE’ with the message you want to display to your visitors. This will display a blank page with your desired message.

Limit The Excerpt’s Word Count

WordPress has a great function when writing posts, called the ‘More’ tag. This will limit the amount of words that we want to display on our post listing page. Although this is a great function how many of us end up adding too many characters or words before the ‘More’ tag and this can really throw out you nice page designs. There is a code snippet that we can use and this will automatically limit the amount of words that will be displayed when displaying our excepts:

add_filter('excerpt_length', 'my_excerpt_length');
function my_excerpt_length( $length ){
	return 10;
}

This code snippet will limit the words to 10 words displayed within our WordPress excerpt. Simply change the number of words that you wish to display.

Remove Elements From The Header

There may be times when you are working on a site for yourself or a client that you want to remove certain elements from being displayed within your theme header. In particular, the generator meta tag, the RSD link and the wlwmanifest link won’t be of much use to many users:

<meta name="generator" content="WordPress 3.8.1">
<link rel="EditURI" type="application/rsd+xml" title="RSD" href="http://example.com/xmlrpc.php?rsd">
<link rel="wlwmanifest" type="application/wlwmanifest+xml" href="http://example.com/wp-includes/wlwmanifest.xml">

To remove these attributes from being displayed we can use the following code snippet:

add_filter('the_generator', create_function('', 'return "";'));
remove_action('wp_head', 'rsd_link');
remove_action('wp_head', 'wlwmanifest_link');

Change WordPress Dashboard Login Logo

A cool stylish thing to do when creating a WordPress site for a client is to change the logo that is displayed on the WordPress login page.

add_action( 'login_head', 'my_custom_login');
function my_custom_login() {
	echo '<style type="text/css">
	h1 a { background-image:url('. get_stylesheet_directory_uri() . '/images/login-logo.png' . ') !important; margin-bottom: 10px; }
	padding: 20px;}
	</style>
	<script type="text/javascript">window.onload = function(){document.getElementById("login").getElementsByTagName("a")[0].href = "'. home_url() . '";document.getElementById("login").getElementsByTagName("a")[0].title = "Go to site";}</script>';
}

This will display your choosen logo which you will call ‘login-logo.png’ and upload to your themes’ images directory.

Display Content Only To Logged-In Users

You may have converted your WordPress site into a membership type site and you find yourself only wanting to display messages to those users that have successfully logged into your site:

add_shortcode( 'loggedin', 'display_loggedin' );
function display_loggedin( $atts, $content = null ) {
	if( is_user_logged_in() ) return '<p>' . $content . '</p>';
	else return;
}

This code creates a new shortcode with which to wrap content in order to hide it from casual visitors but not logged-in users.

Delete Default Widgets

If you are not using the default WordPress widgets, then why not remove them from your site:

function unregister_default_widgets() {
     unregister_widget('WP_Widget_Pages');
     unregister_widget('WP_Widget_Calendar');
     unregister_widget('WP_Widget_Archives');
     unregister_widget('WP_Widget_Links');
     unregister_widget('WP_Widget_Meta');
     unregister_widget('WP_Widget_Search');
     unregister_widget('WP_Widget_Text');
     unregister_widget('WP_Widget_Categories');
     unregister_widget('WP_Widget_Recent_Posts');
     unregister_widget('WP_Widget_Recent_Comments');
     unregister_widget('WP_Widget_RSS');
     unregister_widget('WP_Widget_Tag_Cloud');
     unregister_widget('WP_Nav_Menu_Widget');
     unregister_widget('Twenty_Eleven_Ephemera_Widget');
 }
 add_action('widgets_init', 'unregister_default_widgets', 11);

Simply remove any widgets from the above code snippet that you want o keep.

Redirect WordPress Feeds to Feedburner

It’s great that WordPress offers feeds out of the box. But if you want statistics about your subscribers, you’ll have to use FeedBurner or a similar service. To redirect your feed to one of these, use the following snippet:

add_action('template_redirect', 'my_rss_redirect');
function my_rss_redirect() {
	if ( is_feed() && !preg_match('/feedburner|feedvalidator/i', $_SERVER['HTTP_USER_AGENT'])){
		header('Location: http://feeds.feedburner.com/YOUR FEEDBURNER USERNAME');
		header('HTTP/1.1 302 Temporary Redirect');
	}
}

In the above code snippet, simply replace ‘YOUR FEEDBURNER USERNAME’ with your Feedburner Username.

Display Featured Images In Feed

To encourage subscribers to visit your website, rather than letting them just consume content through your RSS feed, you might want to display only the excerpt and featured image of posts. But WordPress doesn’t display the featured image in the RSS feed by default. Use the following code to do so. You can even add HTML to it.

add_filter('the_content_feed', 'rss_post_thumbnail');
function rss_post_thumbnail($content) {
	global $post;
	if( has_post_thumbnail($post->ID) )
		$content = '<p>' . get_the_post_thumbnail($post->ID, 'thumbnail') . '</p>' . $content;
	return $content;
}

Display Content Only To RSS Subscribers

To increase subscribers to your RSS feed, you could offer a gift available only to them. The code below creates a new shortcode with which to wrap content in order to hide it from regular visitors but not from RSS subscribers.

add_shortcode( 'feedonly', 'my_feedonly_content' );
function my_feedonly_content( $atts, $content = null ) {
	if( is_feed() ) return '<p>' . $content . '</p>';
	else return;
}