Ensure code meets coding standards.

Don't allow the current post to be selected as the random post.
Always return the last 100 matching items and select the random post from one of those.
Updated styles to work with TwentyNineteen.
Tested in WordPress 5.0

Author: wpscholar

RandomPostOnRefresh.php

@@ -6,7 +6,7 @@
  * Plugin URI: http://wpscholar.com/wordpress-plugins/random-post-on-refresh/
  * Author: Micah Wood
  * Author URI: http://wpscholar.com
- * Version: 1.0
+ * Version: 1.1
  * Text Domain: random-post-on-refresh
  * License: GPL3
  * License URI: http://www.gnu.org/licenses/gpl-3.0.html
@@ -32,14 +32,18 @@ public static function initialize() {
 			add_shortcode( self::SHORTCODE, array( __CLASS__, 'shortcode' ) );
 		}
 
+		/**
+		 * Enqueue style.
+		 */
 		public static function wp_enqueue_scripts() {
-			wp_register_style( self::SHORTCODE, plugins_url( '/assets/random-post-on-refresh.css', __FILE__ ) );
+			$plugin_version = get_file_data( __FILE__, array( 'Version' ), 'plugin' );
+			wp_register_style( self::SHORTCODE, plugins_url( '/assets/random-post-on-refresh.css', __FILE__ ), array(), $plugin_version );
 		}
 
 		/**
 		 * Shortcode handler
 		 *
-		 * @param array $atts
+		 * @param array $atts Shortcode attributes
 		 *
 		 * @return bool|string
 		 */
@@ -66,15 +70,20 @@ public static function shortcode( $atts ) {
 
 			$image_size = $atts['size'];
 
-			$groups = array_filter( array_map( function ( $group ) {
-				return self::list_to_array( $group );
-			}, self::list_to_array( $atts['show'], '|' ) ) );
+			$groups = array_filter(
+				array_map(
+					function ( $group ) {
+						return self::list_to_array( $group );
+					},
+					self::list_to_array( $atts['show'], '|' )
+				)
+			);
 
 			$can_show = [ 'title', 'image', 'excerpt', 'content' ];
-			$show = array_merge( ...$groups );
+			$show     = array_merge( ...$groups );
 
-			$show_title = in_array( 'title', $show, true );
-			$show_image = in_array( 'image', $show, true );
+			$show_title   = in_array( 'title', $show, true );
+			$show_image   = in_array( 'image', $show, true );
 			$show_excerpt = in_array( 'excerpt', $show, true );
 			$show_content = in_array( 'content', $show, true );
 
@@ -89,7 +98,9 @@ public static function shortcode( $atts ) {
 			// Taxonomy validation
 			if ( ! empty( $atts['taxonomy'] ) && ! taxonomy_exists( $atts['taxonomy'] ) ) {
 				return self::error(
-					sprintf( __( 'Sorry, taxonomy "%s" is invalid. Valid options are: %s. Please check your shortcode implementation.', 'random-post-on-refresh' ),
+					sprintf(
+						// Translators: %1$s is replaced with taxonomy shortcode argument and %2$s is replaced with a comma-separated list of available taxonomies.
+						__( 'Sorry, taxonomy "%1$s" is invalid. Valid options are: %2$s. Please check your shortcode implementation.', 'random-post-on-refresh' ),
 						$atts['taxonomy'],
 						implode( ', ', get_taxonomies() )
 					),
@@ -100,14 +111,14 @@ public static function shortcode( $atts ) {
 			// Taxonomy/term attribute validation
 			if ( ! empty( $atts['terms'] ) && empty( $atts['taxonomy'] ) ) {
 				return self::error(
-					sprintf( __( 'Sorry, you cannot use the terms attribute without the taxonomy attribute. Please check your shortcode implementation.', 'random-post-on-refresh' ), $post_type ),
+					__( 'Sorry, you cannot use the terms attribute without the taxonomy attribute. Please check your shortcode implementation.', 'random-post-on-refresh' ),
 					'[' . self::SHORTCODE . ' terms="' . $atts['terms'] . '"]'
 				);
 			}
 
 			if ( empty( $atts['terms'] ) && ! empty( $atts['taxonomy'] ) ) {
 				return self::error(
-					sprintf( __( 'Sorry, you cannot use the taxonomy attribute without the terms attribute. Please check your shortcode implementation.', 'random-post-on-refresh' ), $post_type ),
+					__( 'Sorry, you cannot use the taxonomy attribute without the terms attribute. Please check your shortcode implementation.', 'random-post-on-refresh' ),
 					'[' . self::SHORTCODE . ' taxonomy="' . $atts['taxonomy'] . '"]'
 				);
 			}
@@ -119,7 +130,8 @@ public static function shortcode( $atts ) {
 				if ( ! post_type_exists( $post_type ) ) {
 					return self::error(
 						sprintf(
-							__( 'Sorry, post type "%s" is invalid. Valid options are: %s. Please check your shortcode implementation.', 'random-post-on-refresh' ),
+							// Translators: %1$s is replaced with post_type shortcode argument and %2$s is replaced with a comma-separated list of available post types.
+							__( 'Sorry, post type "%1$s" is invalid. Valid options are: %2$s. Please check your shortcode implementation.', 'random-post-on-refresh' ),
 							$post_type,
 							implode( ', ', get_post_types( [ 'public' => true ] ) )
 						),
@@ -153,7 +165,7 @@ public static function shortcode( $atts ) {
 				$terms = self::parse_id_list( $atts['terms'] );
 				if ( 'category' === $atts['taxonomy'] ) {
 					$query_args['category__in'] = $terms;
-				} else if ( 'post_tag' === $atts['taxonomy'] ) {
+				} elseif ( 'post_tag' === $atts['taxonomy'] ) {
 					$query_args['tag__in'] = $terms;
 				} else {
 					$query_args['tax_query'] = [
@@ -167,6 +179,9 @@ public static function shortcode( $atts ) {
 				$query_args['meta_query'] = [ [ 'key' => '_thumbnail_id' ] ];
 			}
 
+			// Never load the current post.
+			$query_args['post__not_in'][] = get_the_ID();
+
 			$query = new WP_Query( $query_args );
 
 			if ( ! $query->have_posts() ) {
@@ -178,6 +193,8 @@ public static function shortcode( $atts ) {
 			$posts = $query->posts;
 
 			/**
+			 * The randomly selected post.
+			 *
 			 * @var WP_Post $post
 			 */
 			$post = $posts[ array_rand( $posts ) ];
@@ -218,10 +235,17 @@ public static function shortcode( $atts ) {
 
 			return sprintf(
 				'<div class="random-post-on-refresh %s"><a href="%s">%s</a></div>',
-				esc_attr( implode( ' ', array_filter( [
-					count( $groups ) > 1 ? '--has-groups' : '',
-					$atts['class']
-				] ) ) ),
+				esc_attr(
+					implode(
+						' ',
+						array_filter(
+							[
+								count( $groups ) > 1 ? '--has-groups' : '',
+								$atts['class'],
+							]
+						)
+					)
+				),
 				esc_url( get_the_permalink( $post ) ),
 				implode( '', array_filter( $display ) )
 			);
@@ -230,7 +254,7 @@ public static function shortcode( $atts ) {
 		/**
 		 * Parse an ID list into an array.
 		 *
-		 * @param string $list
+		 * @param string $list A comma separated list of IDs
 		 *
 		 * @return int[]
 		 */
@@ -246,8 +270,8 @@ public static function parse_id_list( $list ) {
 		/**
 		 * Convert a list (string) to an array
 		 *
-		 * @param string $list
-		 * @param string $delimiter
+		 * @param string $list A delimiter separated list of items
+		 * @param string $delimiter The delimiter used to separate items.
 		 *
 		 * @return array
 		 */
@@ -258,7 +282,7 @@ public static function list_to_array( $list, $delimiter = ',' ) {
 		/**
 		 * Get the excerpt for a specific post (outside of the loop).
 		 *
-		 * @param WP_Post $post
+		 * @param WP_Post $post The WordPress post.
 		 *
 		 * @return string
 		 */
@@ -271,9 +295,9 @@ public static function get_the_excerpt( WP_Post $post ) {
 		/**
 		 * Setup error message.
 		 *
-		 * @param string $message
+		 * @param string $message The error message to display.
 		 *
-		 * @param string $example
+		 * @param string $example (optional) An example shortcode usage.
 		 *
 		 * @return string
 		 */
@@ -298,4 +322,4 @@ public static function error( $message, $example = '' ) {
 
 	RandomPostOnRefresh::initialize();
 
-}
+}

assets/random-post-on-refresh.css

@@ -1,5 +1,6 @@
 .random-post-on-refresh {
-    margin: 10px 0;
+    margin-top: 10px;
+    margin-bottom: 10px;
 }
 
 .random-post-on-refresh a,
@@ -51,4 +52,4 @@
 .random-post-on-refresh-error p:last-of-type {
     margin-bottom: 0;
     padding-bottom: 0;
-}
+}

readme.txt

@@ -1,10 +1,10 @@
 === Random Post on Refresh ===
-Contributors: woodent, Imzodigital
+Contributors: woodent, wpscholar, Imzodigital
 Donate link: https://www.paypal.me/wpscholar
 Tags: random post, post rotation, different post
 Requires at least: 4.5
-Tested up to: 4.9.4
-Stable tag: 1.0
+Tested up to: 5.0
+Stable tag: 1.1
 License: GPLv3
 License URI: http://www.gnu.org/licenses/gpl-3.0.html
 
@@ -77,9 +77,20 @@ Keep in mind that any of these attributes can be combined as needed.  Example: `
 
 == Changelog ==
 
+= 1.1 =
+
+* Ensure code meets coding standards.
+* Don't allow the current post to be selected as the random post.
+* Always return the last 100 matching items and select the random post from one of those.
+* Tested in WordPress 5.0
+
 = 1.0 =
 
 * Tested in WordPress version 4.9.2
 
 == Upgrade Notice ==
 
+= 1.1 =
+
+* The latest update pulls from a larger selection of matching posts before selecting a random post. Works with WordPress 5.0.
+