Create base asset class

src/Assets/BaseAsset.php

@@ -0,0 +1,150 @@
+<?php
+declare( strict_types=1 );
+
+namespace Automattic\WooCommerce\GoogleForWC\Assets;
+
+use Closure;
+
+/**
+ * Class BaseAsset
+ *
+ * @package Automattic\WooCommerce\GoogleForWC\Assets
+ */
+abstract class BaseAsset implements Asset {
+
+	/**
+	 * Priority for registering an asset.
+	 *
+	 * @var int
+	 */
+	protected $registration_priority = 1;
+
+	/**
+	 * Priority for enqueuing an asset.
+	 *
+	 * @var int
+	 */
+	protected $enqueue_priority = 10;
+
+	/**
+	 * Priority for dequeuing an asset.
+	 *
+	 * @var int
+	 */
+	protected $dequeue_priority = 50;
+
+	/**
+	 * The asset handle.
+	 *
+	 * @var string
+	 */
+	protected $handle;
+
+	/**
+	 * Get the handle of the asset. The handle serves as the ID within WordPress.
+	 *
+	 * @return string
+	 */
+	public function get_handle(): string {
+		return $this->handle;
+	}
+
+	/**
+	 * Enqueue the asset within WordPress.
+	 */
+	public function enqueue(): void {
+		$this->defer_action(
+			$this->get_enqueue_action(),
+			$this->get_enqueue_closure(),
+			$this->enqueue_priority
+		);
+	}
+
+	/**
+	 * Dequeue the asset within WordPress.
+	 */
+	public function dequeue(): void {
+		$this->defer_action(
+			$this->get_dequeue_action(),
+			$this->get_dequeue_closure(),
+			$this->dequeue_priority
+		);
+	}
+
+	/**
+	 * Register a service.
+	 */
+	public function register(): void {
+		$this->defer_action(
+			$this->get_register_action(),
+			$this->get_register_closure(),
+			$this->registration_priority
+		);
+	}
+
+	/**
+	 * Get the register action to use.
+	 *
+	 * @since 0.1.0
+	 *
+	 * @return string Register action to use.
+	 */
+	protected function get_register_action(): string {
+		return $this->get_enqueue_action();
+	}
+
+	/**
+	 * Get the enqueue action to use.
+	 *
+	 * @return string
+	 */
+	protected function get_enqueue_action(): string {
+		return 'wp_enqueue_scripts';
+	}
+
+	/**
+	 * Get the enqueue action to use.
+	 *
+	 * @return string
+	 */
+	protected function get_dequeue_action(): string {
+		return 'wp_print_scripts';
+	}
+
+	/**
+	 * Add a closure to an action, or run it immediately if the action has already fired.
+	 *
+	 * @param string  $action
+	 * @param Closure $closure
+	 * @param int     $priority
+	 */
+	protected function defer_action( string $action, Closure $closure, int $priority = 10 ): void {
+		if ( did_action( $action ) ) {
+			$closure();
+			return;
+		}
+
+		add_action( $action, $closure, $priority );
+	}
+
+	/**
+	 * Get the enqueue closure to use.
+	 *
+	 * @return Closure
+	 */
+	abstract protected function get_register_closure(): Closure;
+
+	/**
+	 * Get the enqueue closure to use.
+	 *
+	 * @return Closure
+	 */
+	abstract protected function get_enqueue_closure(): Closure;
+
+	/**
+	 * Get the dequeue closure to use.
+	 *
+	 * @return Closure
+	 */
+	abstract protected function get_dequeue_closure(): Closure;
+}