Wordpress Snippets

There’s a lot of things you can do to improve and extend Wordpress, beyond plugins and themes.

Deny script access

Add to the top of a script (after <?php)

if ( !defined('ABSPATH') ) {
	die("<!-- Not allowed -->");
}

If anyone tries to run the script file directly, instead of Wordpress running it, it will fail. This can stop others from gathering details directly from scripts.

Scripts, css, fonts

Choose, modify, or erase unneeded ones.

function custom_replace_css() {
  // for those plugins that add fonts but not together:
  wp_deregister_style('freehand-regular-latin,all');
  wp_deregister_style('over_the_rainbow-regular-latin,all');  

  // list fonts here separated by |
  $allfonts='Freehand:regular|Over+the+Rainbow:regular';
  wp_register_style("many-fonts","https://fonts.googleapis.com/css?family=$allfonts&subset=latin,all");
  wp_enqueue_style('many-fonts');

  // remove unneeded scripts by their tag (usually id= but look in the plugin code)
  wp_deregister_style('script-tag');
}

add_action('wp_enqueue_scripts','custom_replace_css',11);

From here

function mytheme_dequeue_fonts() {
         wp_dequeue_style( 'twentytwelve-fonts' );
      }

add_action( 'wp_enqueue_scripts', 'mytheme_dequeue_fonts', 11 );

Ref: https://wordpress.stackexchange.com/questions/66524/remove-open-sans-from-twenty-twelve-theme

Use google jquery

     /* Disable WordPress jQuery */
     wp_deregister_script('jquery');
     /* Register jQuery's CDN Version */
     wp_register_script('jquery', 'https://code.jquery.com/jquery-1.7.2.min.js');
     /* Or Use Google CDN Version */
     wp_register_script('jquery', 'https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js');
     /* Enable New Script */
     wp_enqueue_script('jquery');

Ref: here (archive.org)

Getting ready to do some remodeling. Credit

Redirect Comment post

You can do a lot more, but here’s an idea

add_action('comment_post_redirect', 'your_redirect_function');

// A function that redirects your users after they have commented.
function your_redirect_function ($location, $comment) {
    // Here all you need to do is return the url of your target page.
    $page = 'http://www.stackoverflow.com';
    return $page;
}

Ref: https://stackoverflow.com/questions/18561939/wordpress-redirect-user-after-commenting

Shortcodes and Widgets

To let widgets use shortcodes (well, process them, that is…), add to ‘‘functions.php’’ or custom plugin:

add_filter('widget_text', 'do_shortcode');

Ref: https://digwp.com/2010/03/shortcodes-in-widgets/

Remove post features

Sometimes you need to remove post features, like excerpt or trackbacks.

<?php remove_post_type_support( $post_type, $supports ) ?>

where $post_type is usually ‘post’ and type is the feature to remove see Codex for a list of types.

Example:

add_action( 'init', 'my_custom_init' );
function my_custom_init() {
	remove_post_type_support( 'post', 'excerpt' );
}

Add Design Credit

<?php
// Put a tagline on the admin panel
function remove_footer_admin () {
?>

<span id="footer-thankyou">
Fueled by <a href="https://www.wordpress.org" target="_blank">WordPress</a>|
Site Design and Layout by <a href="https://www.supertechcrew.com" target="_blank">Matt Bagley</a>|
</span><!-- .site-info -->

<?php    
}
add_filter('admin_footer_text', 'remove_footer_admin');
?>

Load Scripts Conditionally

if( !is_admin()){
   wp_register_script('flex', get_template_directory_uri() . '/js/flexslider.js', array('jquery'), '1.8.0', true );
   wp_register_script('vids', get_template_directory_uri() . '/js/fitvids.js', array('jquery'), '1.0.0', true );
   wp_register_script('custom', get_template_directory_uri() . '/js/custom.js', array('jquery'), '1.0.0', true );
}

Ref: https://www.organizedthemes.com/loading-scripts-conditionally/

Get list of scripts

Look in plugin code, or:

global $wp_styles;

    foreach($wp_styles as $main_obj => $vals){
    if(is_array($vals)){
        // echo var_dump($vals);
        foreach($vals as $name => $obj){
            if(!empty($obj->handle)){
                // echo $obj->handle, '<br />';
                echo '"'.$obj->handle. '", ';
            }    
        }
    }
}

Ref: https://stackoverflow.com/a/12796054

Remove url in comments

function remove_comment_fields($fields) {
    unset($fields['url']);
    return $fields;
}
add_filter('comment_form_default_fields','remove_comment_fields');

Break out of Frames

I will not be trapped…

// Break Out of Frames for WordPress
function break_out_of_frames() {
	if (!is_preview()) {
		echo "\n<script type=\"text/javascript\">";
		echo "\n<!--";
		echo "\nif (parent.frames.length > 0) { parent.location.href = location.href; }";
		echo "\n-->";
		echo "\n</script>\n\n";
	}
}
add_action('wp_head', 'break_out_of_frames');

Set attached image as Featured

// @ https://wp-mix.com/set-attachment-featured-image/
add_filter('the_content', 'set_featured_image_from_attachment');
function set_featured_image_from_attachment($content) {
	global $post;
	if (has_post_thumbnail()) {
		// display the featured image
		$content = the_post_thumbnail() . $content;
	} else {
		// get & set the featured image
		$attachments = get_children(array(
			'post_parent' => $post->ID,
			'post_status' => 'inherit',
			'post_type' => 'attachment',
			'post_mime_type' => 'image',
			'order' => 'ASC',
			'orderby' => 'menu_order'
		));
		if ($attachments) {
			foreach ($attachments as $attachment) {
				set_post_thumbnail($post->ID, $attachment->ID);
				break;
			}
			// display the featured image
			$content = the_post_thumbnail() . $content;
		}
	}
	return $content;
}

Add thumbnail to feed

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

Add previous/next Name

There should be a better way to do this.

<?php
	$p = get_adjacent_post(false, '', true);
	if(!empty($p)) echo '<div class="prev"><a href="' . get_permalink($p->ID) . '" title="' . $p->post_title . '">' . $p->post_title . '</a></div>';

	$n = get_adjacent_post(false, '', false);
	if(!empty($n)) echo '<div class="next"><a href="' . get_permalink($n->ID) . '" title="' .
$n->post_title . '">' . $n->post_title . '</a></div>';
?>

Show Single Result

For search results.

add_action('template_redirect', 'redirect_single_post');
function redirect_single_post() {
    if (is_search()) {
        global $wp_query;
        if ($wp_query->post_count == 1 && $wp_query->max_num_pages == 1) {
            wp_redirect( get_permalink( $wp_query->posts['0']->ID ) );
            exit;
        }
    }
}

Req Real Comments

Set minimum length on comments.

add_filter( 'preprocess_comment', 'minimal_comment_length' );
function minimal_comment_length( $commentdata ) {
	$minimalCommentLength = 20;
	if ( strlen( trim( $commentdata['comment_content'] ) ) < $minimalCommentLength )
        {
		wp_die( 'All comments must be at least ' . $minimalCommentLength . ' characters long.' );
        }
	return $commentdata;
}

Admin notice

Show a note only to other admins.

// Admin Note
function adminnote($atts, $content = NULL){
	if(current_user_can('edit_themes') || is_user_logged_in()){
		return 'Admin Notice‘ . $content . ‘';  	
}  }  add_shortcode('note', 'adminnote');  
// Use [note]This will appear only to admins[/note]

Add Content to Feed

function feedFilter($query) {
    if ($query->is_feed) {
        add_filter('the_content','feedContentFilter');
    }
    return $query;
}
add_filter('pre_get_posts','feedFilter');

function feedContentFilter($content) {
    $content .= '<p>Extra RSS content goes here... </p>';

    return $content;
}

Allow PHP in Widgets

function php_text($text) {
 if (strpos($text, '<' . '?') !== false) {
 ob_start();
 eval('?' . '>' . $text);
 $text = ob_get_contents();
 ob_end_clean();
 }
 return $text;
}
add_filter('widget_text', 'php_text', 99)

Style First Paragraph

function first_paragraph($content){

global $post;

if ($post->post_type == "post"){
     return preg_replace('/&lt;p([^>]+)?>/', '&lt;p$1 class="first">', $content, 1); }
else {
       return $content;
      }
}
add_filter('the_content', 'first_paragraph');

Add Thumbnails to Post List

/****** Add Thumbnails in Manage Posts/Pages List ******/
if ( !function_exists('AddThumbColumn') && function_exists('add_theme_support') ) {

    // for post and page
    add_theme_support('post-thumbnails', array( 'post', 'page' ) );

    function AddThumbColumn($cols) {

        $cols['thumbnail'] = __('Thumbnail');

        return $cols;
    }

    function AddThumbValue($column_name, $post_id) {

            $width = (int) 35;
            $height = (int) 35;

            if ( 'thumbnail' == $column_name ) {
                // thumbnail of WP 2.9
                $thumbnail_id = get_post_meta( $post_id, '_thumbnail_id', true );
                // image from gallery
                $attachments = get_children( array('post_parent' => $post_id, 'post_type' => 'attachment', 'post_mime_type' => 'image') );
                if ($thumbnail_id)
                    $thumb = wp_get_attachment_image( $thumbnail_id, array($width, $height), true );
                elseif ($attachments) {
                    foreach ( $attachments as $attachment_id => $attachment ) {
                        $thumb = wp_get_attachment_image( $attachment_id, array($width, $height), true );
                    }
                }
                    if ( isset($thumb) && $thumb ) {
                        echo $thumb;
                    } else {
                        echo __('None');
                    }
            }
    }

    // for posts
    add_filter( 'manage_posts_columns', 'AddThumbColumn' );
    add_action( 'manage_posts_custom_column', 'AddThumbValue', 10, 2 );

    // for pages
    add_filter( 'manage_pages_columns', 'AddThumbColumn' );
    add_action( 'manage_pages_custom_column', 'AddThumbValue', 10, 2 );

Remove Images from Content

This is useful for showing full content on home page without the images. From here.

add_filter('the_content', 'filter_images',2);

function filter_images($content){
    return preg_replace(‘/< img alt=”” />]+./’,”,$content);
}

This one may be better for custom themes.

<?php
  $content = get_the_content();
  $postOutput = preg_replace('/<img[^>]+./','', $content);
  echo $postOutput;
?>

Deny script access#

Scripts, css, fonts#

Redirect Comment post#

Shortcodes and Widgets#

Remove post features#

Add Design Credit#

Load Scripts Conditionally#

Get list of scripts#

Remove url in comments#

Break out of Frames#

Set attached image as Featured#

Add thumbnail to feed#

Add previous/next Name#

Show Single Result#

Req Real Comments#

Admin notice#

Add Content to Feed#

Allow PHP in Widgets#

Style First Paragraph#

Add Thumbnails to Post List#

Remove Images from Content#