Allow attributes to register hooks

.github/workflows/coding-standards.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: [7.4]
+        php: [8.0]
 
     name: Coding Standards
 

src/mantle/support/attributes/class-action.php

@@ -0,0 +1,26 @@
+<?php
+/**
+ * Action class file
+ *
+ * @package Mantle
+ */
+
+namespace Mantle\Support\Attributes;
+
+use Attribute;
+
+/**
+ * Hook Action Attribute
+ *
+ * Used to hook a method to an WordPress action at a specific priority.
+ */
+#[Attribute]
+class Action {
+	/**
+	 * Constructor.
+	 *
+	 * @param string $action Action name.
+	 * @param int    $priority Priority, defaults to 10.
+	 */
+	public function __construct( public string $action, public int $priority = 10 ) {}
+}

src/mantle/support/class-service-provider.php

@@ -9,8 +9,10 @@
 
 use Mantle\Console\Command;
 use Mantle\Contracts\Application;
+use Mantle\Support\Attributes\Action;
 use Mantle\Support\Str;
 use Psr\Log\{LoggerAwareInterface, LoggerAwareTrait};
+use ReflectionClass;
 
 use function Mantle\Support\Helpers\add_action;
 use function Mantle\Support\Helpers\collect;
@@ -64,6 +66,7 @@ public function boot_provider() {
 		}
 
 		$this->boot_action_hooks();
+		$this->boot_attribute_hooks();
 		$this->boot();
 	}
 
@@ -96,6 +99,33 @@ function( string $method ) {
 			);
 	}
 
+	/**
+	 * Boot all attribute actions on the service provider.
+	 */
+	protected function boot_attribute_hooks() {
+		// Abandon if we're not running PHP 8.
+		if ( version_compare( phpversion(), '8.0.0', '<' ) ) {
+			return;
+		}
+
+		$class = new ReflectionClass( static::class );
+
+		foreach ( $class->getMethods() as $method ) {
+			$action_attributes = $method->getAttributes( Action::class );
+
+			if ( empty( $action_attributes ) ) {
+				continue;
+			}
+
+			foreach ( $action_attributes as $attribute ) {
+				$instance = $attribute->newInstance();
+
+				add_action( $instance->action, [ $this, $method->name ], $instance->priority );
+			}
+		}
+
+	}
+
 	/**
 	 * Register a wp-cli command.
 	 *

tests/support/test-service-provider.php

@@ -5,6 +5,7 @@
 use Mantle\Console\Command;
 use Mantle\Contracts\Providers as ProviderContracts;
 use Mantle\Support\Service_Provider;
+use Mantle\Support\Attributes\Action;
 use Mockery as m;
 
 class Test_Service_Provider extends \Mockery\Adapter\Phpunit\MockeryTestCase {
@@ -70,6 +71,22 @@ public function test_hook_method_filter() {
 
 		$this->assertEquals( 15, $value );
 	}
+
+	public function test_hook_attribute() {
+		// Abandon if we're not running PHP 8.
+		if ( version_compare( phpversion(), '8.0.0', '<' ) ) {
+			$this->markTestSkipped( 'Requires PHP 8.0.0 or greater.' );
+			return;
+		}
+
+		$app = m::mock( Application::class )->makePartial();
+		$app->register( Provider_Test_Hook::class );
+		$app->boot();
+
+		do_action( 'testable-attribute-hook' );
+
+		$this->assertTrue( $_SERVER['__custom_hook_fired'] ?? false );
+	}
 }
 
 class Provider_Test_Hook extends Service_Provider {
@@ -80,4 +97,13 @@ public function on_custom_hook() {
 	public function on_custom_filter( $value ) {
 		return $value + 10;
 	}
+
+	#[Action('testable-attribute-hook', 20)]
+	public function handle_custom_hook() {
+		$_SERVER['__custom_hook_fired'] = true;
+	}
+
+	public function handle_custom_filter( $value ) {
+		return $value + 100;
+	}
 }