Simplify

classes/class-web-vitals.php

-<?php
-/**
- * Google's Web Vitals measurements.
- *
- * @link https://github.com/GoogleChrome/web-vitals
- *
- * @package eth-web-vitals
- */
-
-namespace ETH\Web_Vitals;
-
-/**
- * Class Web_Vitals.
- */
-class Web_Vitals {
-	use Singleton;
-
-	/**
-	 * Reporting category for analytics provider.
-	 */
-	protected const EVENT_CATEGORY = 'Web Vitals';
-
-	/**
-	 * Output priority.
-	 *
-	 * Load early to capture as soon as possible.
-	 */
-	protected const OUTPUT_PRIORITY = 0;
-
-	/**
-	 * Web_Vitals constructor.
-	 */
-	protected function __construct() {
-		add_action( 'wp_head', [ $this, 'render' ], static::OUTPUT_PRIORITY );
-	}
-
-	/**
-	 * Output the Web Vitals script.
-	 */
-	public function render(): void {
-		$data = [
-			'config' => [
-				'eventCategory' => static::EVENT_CATEGORY,
-			],
-			'queue'  => [],
-		];
-
-		?>
-		<script>
-			window.ethWebVitals = window.ethWebVitals || {};
-			window.ethWebVitals = <?php echo wp_json_encode( $data ); ?>;
-
-			<?php echo file_get_contents( PLUGIN_PATH . 'assets/build/web-vitals.js' ); ?>
-		</script>
-		<?php
-	}
-}

classes/trait-singleton.php

-<?php
-/**
- * Singleton trait which implements Singleton pattern in any class in which this trait is used.
- *
- * Dependent items can use the `pmc_singleton_init_{$called_class}` hook to
- * execute code immediately after _init() is called.
- *
- * Using the singleton pattern in WordPress is an easy way to protect against
- * mistakes caused by creating multiple objects or multiple initialization
- * of classes which need to be initialized only once.
- *
- * With complex plugins, there are many cases where multiple copies of
- * the plugin would load, and action hooks would load (and trigger) multiple
- * times.
- *
- * If you're planning on using a global variable, then you should implement
- * this trait. Singletons are a way to safely use globals; they let you
- * access and set the global from anywhere, without risk of collision.
- *
- * If any method in a class needs to be aware of "state", then you should
- * implement this trait in that class.
- *
- * If any method in the class need to "talk" to another or be aware of what
- * another method has done, then you should implement this trait in that class.
- *
- * If you specifically need multiple objects, then use a normal class.
- *
- * If you're unsure, ask in engineering chat.
- *
- * @since 2017-06-19 Amit Gupta
- */
-
-namespace ETH\Web_Vitals;
-
-trait Singleton {
-	protected static $_instance = array();
-
-	/**
-	 * Protected class constructor to prevent direct object creation
-	 *
-	 * This is meant to be overridden in the classes which implement
-	 * this trait. This is ideal for doing stuff that you only want to
-	 * do once, such as hooking into actions and filters, etc.
-	 */
-	protected function  __construct() { }
-
-	/**
-	 * Prevent object cloning
-	 */
-	final protected function  __clone() { }
-
-	/**
-	 * This method returns new or existing Singleton instance
-	 * of the class for which it is called. This method is set
-	 * as final intentionally, it is not meant to be overridden.
-	 *
-	 * @return object|static Singleton instance of the class.
-	 */
-	final public static function get_instance() {
-		/**
-		 * If this trait is implemented in a class which has multiple
-		 * sub-classes then static::$_instance will be overwritten with the most recent
-		 * sub-class instance. Thanks to late static binding
-		 * we use get_called_class() to grab the called class name, and store
-		 * a key=>value pair for each `classname => instance` in self::$_instance
-		 * for each sub-class.
-		 */
-		$called_class = get_called_class();
-
-		if ( ! isset( static::$_instance[ $called_class ] ) ) {
-			static::$_instance[ $called_class ] = new $called_class();
-		}
-
-		return static::$_instance[ $called_class ];
-
-	}
-
-}

pmc-performance-metrics.php

@@ -4,14 +4,32 @@
  * Plugin URI: https://ethitter.com
  * Description: Record performance metrics in analytics platforms.
  * Version: 1.0
- * License: PMC Proprietary. All rights reserved.
- * Author: PMC
+ * License: GPLv2
+ * Author: Erick Hitter
 */
 
 namespace ETH\Web_Vitals;
 
 define( 'ETH\\Web_Vitals\\PLUGIN_PATH', plugin_dir_path( __FILE__ ) );
 
-require_once __DIR__ . '/classes/trait-singleton.php';
-require_once __DIR__ . '/classes/class-web-vitals.php';
-Web_Vitals::get_instance();
+/**
+ * Output the Web Vitals script.
+ */
+function render(): void {
+	$data = [
+		'config' => [
+			'eventCategory' => 'Web Vitals',
+		],
+		'queue'  => [],
+	];
+
+	?>
+	<script>
+		window.ethWebVitals = window.ethWebVitals || {};
+		window.ethWebVitals = <?php echo wp_json_encode( $data ); ?>;
+		<?php echo file_get_contents( PLUGIN_PATH . 'assets/build/web-vitals.js' ); ?>
+	</script>
+	<?php
+}
+
+add_action( 'wp_head', __NAMESPACE__ . '\render', 0 );