Prepare for rocket head ordering

inc/Engine/Common/Head/ElementTrait.php

@@ -0,0 +1,139 @@
+<?php
+declare(strict_types=1);
+namespace WP_Rocket\Engine\Common\Head;
+
+/**
+ * Element trait.
+ */
+trait ElementTrait {
+	/**
+	 * Preload link.
+	 *
+	 * @param array $args Element args.
+	 * @return array|string[]
+	 */
+	protected function preload_link( array $args = [] ) {
+		$args['rel'] = 'preload';
+		$args[]      = 'data-rocket-preload';
+		return $this->link( $args );
+	}
+
+	/**
+	 * Preconnect link.
+	 *
+	 * @param array $args Element args.
+	 * @return array|string[]
+	 */
+	protected function preconnect_link( array $args = [] ) {
+		$args['rel'] = 'preconnect';
+		return $this->link( $args );
+	}
+
+	/**
+	 * Dns_prefetch link.
+	 *
+	 * @param array $args Element args.
+	 * @return array|string[]
+	 */
+	protected function dns_prefetch_link( array $args = [] ) {
+		$args['rel'] = 'dns-prefetch';
+		return $this->link( $args );
+	}
+
+	/**
+	 * Prefetch link.
+	 *
+	 * @param array $args Element args.
+	 * @return array|string[]
+	 */
+	protected function prefetch_link( array $args = [] ) {
+		$args['rel'] = 'prefetch';
+		return $this->link( $args );
+	}
+
+	/**
+	 * Prerender link.
+	 *
+	 * @param array $args Element args.
+	 * @return array|string[]
+	 */
+	protected function prerender_link( array $args = [] ) {
+		$args['rel'] = 'prerender';
+		return $this->link( $args );
+	}
+
+	/**
+	 * Stylesheet link.
+	 *
+	 * @param array $args Element args.
+	 * @return array|string[]
+	 */
+	protected function stylesheet_link( array $args = [] ) {
+		$args['rel'] = 'stylesheet';
+		return $this->link( $args );
+	}
+
+	/**
+	 * Style tag.
+	 *
+	 * @param string $css CSS content.
+	 * @param array  $args Element args.
+	 * @return array|string[]
+	 */
+	protected function style_tag( string $css = '', array $args = [] ) {
+		$element              = [
+			'open_tag' => '<style',
+		];
+		$element             += wp_parse_args(
+			$args,
+			[
+				'inner_content' => $css,
+			]
+		);
+		$element['close_tag'] = '</style>';
+
+		return $element;
+	}
+
+	/**
+	 * Noscript tag.
+	 *
+	 * @param string $content Element contents.
+	 * @param array  $args Element args.
+	 * @return array|string[]
+	 */
+	protected function noscript_tag( string $content = '', array $args = [] ) {
+		$element              = [
+			'open_tag' => '<noscript',
+		];
+		$element             += wp_parse_args(
+			$args,
+			[
+				'inner_content' => $content,
+			]
+			);
+		$element['close_tag'] = '</noscript>';
+
+		return $element;
+	}
+
+	/**
+	 * Generic link tag.
+	 *
+	 * @param array $args Element args.
+	 * @return array|string[]
+	 */
+	private function link( array $args = [] ) {
+		$element  = [
+			'open_tag' => '<link',
+		];
+		$element += wp_parse_args(
+			$args,
+			[
+				'href' => '',
+			]
+		);
+
+		return $element;
+	}
+}

inc/Engine/Common/Head/ServiceProvider.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace WP_Rocket\Engine\Common\Head;
+
+use WP_Rocket\Dependencies\League\Container\ServiceProvider\AbstractServiceProvider;
+
+/**
+ * Service provider.
+ */
+class ServiceProvider extends AbstractServiceProvider {
+	/**
+	 * Array of services provided by this service provider
+	 *
+	 * @var array
+	 */
+	protected $provides = [
+		'common_head_subscriber',
+	];
+
+	/**
+	 * Check if the service provider provides a specific service.
+	 *
+	 * @param string $id The id of the service.
+	 *
+	 * @return bool
+	 */
+	public function provides( string $id ): bool {
+		return in_array( $id, $this->provides, true );
+	}
+
+	/**
+	 * Registers items with the container
+	 *
+	 * @return void
+	 */
+	public function register(): void {
+		$this->getContainer()->addShared( 'common_head_subscriber', Subscriber::class );
+	}
+}

inc/Engine/Common/Head/Subscriber.php

@@ -0,0 +1,168 @@
+<?php
+namespace WP_Rocket\Engine\Common\Head;
+
+use WP_Rocket\Event_Management\Subscriber_Interface;
+
+/**
+ * Head subscriber class.
+ */
+class Subscriber implements Subscriber_Interface {
+
+	/**
+	 * Head elements array.
+	 *
+	 * @var array
+	 */
+	private $head_items = [];
+
+	/**
+	 * Returns an array of events that this subscriber wants to listen to.
+	 *
+	 * The array key is the event name. The value can be:
+	 *
+	 *  * The method name
+	 *  * An array with the method name and priority
+	 *  * An array with the method name, priority and number of accepted arguments
+	 *
+	 * For instance:
+	 *
+	 *  * array('hook_name' => 'method_name')
+	 *  * array('hook_name' => array('method_name', $priority))
+	 *  * array('hook_name' => array('method_name', $priority, $accepted_args))
+	 *  * array('hook_name' => array(array('method_name_1', $priority_1, $accepted_args_1)), array('method_name_2', $priority_2, $accepted_args_2)))
+	 *
+	 * @return array
+	 */
+	public static function get_subscribed_events() {
+		return [
+			'rocket_buffer' => [ 'insert_rocket_head', 100000 ],
+			'rocket_head'   => 'print_head_elements',
+		];
+	}
+
+	/**
+	 * Print all head elements.
+	 *
+	 * @param string $content Head elements HTML.
+	 * @return string
+	 */
+	public function print_head_elements( $content ) {
+		/**
+		 * Filter Head elements array.
+		 *
+		 * @param array $head_items Elements to be added to head after closing of title tag.
+		 *
+		 * Priority 10: preconnect
+		 * Priority 30: preload
+		 * Priority 50: styles
+		 * @returns array
+		 */
+		$items = wpm_apply_filters_typed( 'array', 'rocket_head_items', [] );
+		if ( empty( $items ) ) {
+			return $content;
+		}
+
+		$this->head_items = [];
+		// Combine elements.
+		$elements = '';
+		foreach ( $items as $item ) {
+			// Make sure that we don't have duplication based on `href` inside each `rel`.
+			if ( $this->is_duplicate( $item ) ) {
+				continue;
+			}
+			$elements .= "\n" . $this->prepare_element( $item );
+		}
+
+		return $content . $elements;
+	}
+
+	/**
+	 * Check if the item is duplicate.
+	 *
+	 * @param array $item Item to check.
+	 * @return bool
+	 */
+	private function is_duplicate( $item ) {
+		if ( empty( $item['rel'] ) || empty( $item['href'] ) ) {
+			return false;
+		}
+
+		if ( ! isset( $this->head_items[ $item['rel'] ] ) ) {
+			$this->head_items[ $item['rel'] ] = [];
+		}
+
+		if ( ! isset( $this->head_items[ $item['rel'] ][ $item['href'] ] ) ) {
+			$this->head_items[ $item['rel'] ][ $item['href'] ] = true;
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Prepare element HTML from the item array.
+	 *
+	 * @param array $element Item element.
+	 * @return string
+	 */
+	private function prepare_element( $element ) {
+		$open_tag = '';
+		if ( ! empty( $element['open_tag'] ) ) {
+			$open_tag = $element['open_tag'];
+			unset( $element['open_tag'] );
+		}
+
+		$close_tag = '';
+		if ( ! empty( $element['close_tag'] ) ) {
+			$close_tag = $element['close_tag'];
+			unset( $element['close_tag'] );
+		}
+
+		$inner_content = '';
+		if ( ! empty( $element['inner_content'] ) ) {
+			$inner_content = $element['inner_content'];
+			unset( $element['inner_content'] );
+		}
+
+		$attributes = [];
+
+		ksort( $element, SORT_NATURAL );
+
+		foreach ( $element as $key => $value ) {
+			if ( is_int( $key ) ) {
+				$attributes[] = $value;
+				continue;
+			}
+			$attributes[] = $key . '="' . esc_attr( $value ) . '"';
+		}
+
+		$attributes_html = ! empty( $attributes ) ? ' ' . implode( ' ', $attributes ) : '';
+
+		return $open_tag . $attributes_html . '>' . $inner_content . $close_tag;
+	}
+
+	/**
+	 * Insert rocket_head into the buffer HTML
+	 *
+	 * @param string $html Buffer HTML.
+	 * @return string
+	 */
+	public function insert_rocket_head( $html ) {
+		if ( empty( $html ) ) {
+			return $html;
+		}
+
+		$filtered_buffer = preg_replace(
+			'#</title>#iU',
+			'</title>' . wpm_apply_filters_typed( 'string', 'rocket_head', '' ),
+			$html,
+			1
+		);
+
+		if ( empty( $filtered_buffer ) ) {
+			return $html;
+		}
+
+		return $filtered_buffer;
+	}
+}