From f0bf1c3542233577c9a086f8c2b80c74680c37b9 Mon Sep 17 00:00:00 2001
From: Stefan Kalscheuer <stefan@stklcode.de>
Date: Thu, 9 Apr 2020 12:15:25 +0200
Subject: [PATCH] enqueue styles and scripts if only Gutenberg block is present

Resources have only been added if shortcode or widget hooks have been
triggered before. If we switch to native Gutenberg block, none of the
checks is true and no scripts are available.
---
 includes/class-scliveticker.php | 61 +++++++++++++++++++--------------
 1 file changed, 36 insertions(+), 25 deletions(-)

diff --git a/includes/class-scliveticker.php b/includes/class-scliveticker.php
index dc5446a..7c425bb 100644
--- a/includes/class-scliveticker.php
+++ b/includes/class-scliveticker.php
@@ -80,11 +80,8 @@ class SCLiveticker {
 		// Add shortcode.
 		add_shortcode( 'liveticker', array( __CLASS__, 'shortcode_ticker_show' ) );
 
-		// Enqueue styles.
-		add_action( 'wp_footer', array( __CLASS__, 'enqueue_styles' ) );
-
-		// Enqueue JavaScript.
-		add_action( 'wp_footer', array( __CLASS__, 'enqueue_scripts' ) );
+		// Enqueue styles and JavaScript.
+		add_action( 'wp_footer', array( __CLASS__, 'enqueue_resources' ) );
 
 		// Add AJAX hook if configured.
 		if ( 1 === self::$options['enable_ajax'] ) {
@@ -244,32 +241,15 @@ class SCLiveticker {
 		return $output;
 	}
 
-	/**
-	 * Register frontend CSS.
-	 *
-	 * @return void
-	 */
-	public static function enqueue_styles() {
-		// Only add if shortcode is present.
-		if ( self::$shortcode_present || self::$widget_present ) {
-			wp_enqueue_style(
-				'wplt-css',
-				SCLIVETICKER_BASE . 'styles/liveticker.min.css',
-				'',
-				self::VERSION,
-				'all'
-			);
-		}
-	}
-
 	/**
 	 * Register frontend JS.
 	 *
 	 * @return void
+	 * @since 1.1 Combined former methods "enqueue_styles" and "enqueue_scripts".
 	 */
-	public static function enqueue_scripts() {
+	public static function enqueue_resources() {
 		// Only add if shortcode is present.
-		if ( self::$shortcode_present || self::$widget_present ) {
+		if ( self::$shortcode_present || self::$widget_present || self::block_present() ) {
 			wp_enqueue_script(
 				'scliveticker-js',
 				SCLIVETICKER_BASE . 'scripts/liveticker.min.js',
@@ -288,6 +268,14 @@ class SCLiveticker {
 					'poll_interval' => self::$options['poll_interval'] * 1000,
 				)
 			);
+
+			wp_enqueue_style(
+				'sclt-css',
+				SCLIVETICKER_BASE . 'styles/liveticker.min.css',
+				'',
+				self::VERSION,
+				'all'
+			);
 		}
 	}
 
@@ -458,4 +446,27 @@ class SCLiveticker {
 			. '<span class="sclt-widget-title">' . $title . '</span>'
 			. '</li>';
 	}
+
+	/**
+	 * Check if the Gutenberg block is present in current post.
+	 *
+	 * @return boolean True, if Gutenberg block is present.
+	 * @since 1.1
+	 */
+	private static function block_present() {
+		// We are in WP 5.x environment and blocks are generally present.
+		if ( function_exists( 'has_blocks' ) && has_blocks() ) {
+			/*
+			 * The slightly faster call to ‌has_block( 'scliveticker/ticker' ) produces an "undefined function" error for
+			 * no good reason. Iteration over pased blocks however works fine.
+			 */
+			foreach ( parse_blocks( get_post()->post_content ) as $b ) {
+				if ( 'scliveticker/ticker' === $b['blockName'] ) {
+					return true;
+				}
+			}
+		}
+
+		return false;
+	}
 }