Add capability to generate AMP-only content (AMP-as-Canonical)

amp.php

@@ -16,10 +16,16 @@
 define( 'AMP__VERSION', '0.4.2' );
 
 require_once( AMP__DIR__ . '/back-compat/back-compat.php' );
-require_once( AMP__DIR__ . '/includes/amp-helper-functions.php' );
+require_once(AMP__DIR__ . '/includes/utils/amp-helper-functions.php');
 require_once( AMP__DIR__ . '/includes/admin/functions.php' );
 require_once( AMP__DIR__ . '/includes/settings/class-amp-customizer-settings.php' );
 require_once( AMP__DIR__ . '/includes/settings/class-amp-customizer-design-settings.php' );
+require_once( AMP__DIR__ . '/includes/utils/class-amp-dom-utils.php');
+require_once(AMP__DIR__ . '/includes/utils/class-amp-utils.php');
+require_once(AMP__DIR__ . '/includes/utils/class-amp-render.php');
+require_once(AMP__DIR__ . '/includes/actions/class-paired-mode-actions.php');
+require_once(AMP__DIR__ . '/includes/actions/class-canonical-mode-actions.php');
+require_once( AMP__DIR__ . '/option.php' );
 
 register_activation_hook( __FILE__, 'amp_activate' );
 function amp_activate() {
@@ -45,6 +51,7 @@ function amp_deactivate() {
 
 add_action( 'init', 'amp_init' );
 function amp_init() {
+
 	if ( false === apply_filters( 'amp_is_enabled', true ) ) {
 		return;
 	}
@@ -55,134 +62,62 @@ function amp_init() {
 
 	load_plugin_textdomain( 'amp', false, plugin_basename( AMP__DIR__ ) . '/languages' );
 
-	add_rewrite_endpoint( AMP_QUERY_VAR, EP_PERMALINK );
-	add_post_type_support( 'post', AMP_QUERY_VAR );
+	// If the amp_canonical option has not been setup, or the current
+	// theme does not provide AMP support, then follow the "paired" approach
+	if ( ! get_option('amp_canonical') || ! get_theme_support('amp')) {
+		add_rewrite_endpoint( AMP_QUERY_VAR, EP_PERMALINK );
+		add_post_type_support( 'post', AMP_QUERY_VAR );
+	}
 
-	add_filter( 'request', 'amp_force_query_var_value' );
-	add_action( 'wp', 'amp_maybe_add_actions' );
+	add_filter( 'request', 'AMPUtils::amp_force_query_var_value' );
+	add_action( 'wp', 'amp_add_actions');
 
 	// Redirect the old url of amp page to the updated url.
-	add_filter( 'old_slug_redirect_url', 'amp_redirect_old_slug_to_new_url' );
+	add_filter( 'old_slug_redirect_url', 'AMPUtils::amp_redirect_old_slug_to_new_url' );
 
 	if ( class_exists( 'Jetpack' ) && ! ( defined( 'IS_WPCOM' ) && IS_WPCOM ) ) {
 		require_once( AMP__DIR__ . '/jetpack-helper.php' );
 	}
 }
 
-// Make sure the `amp` query var has an explicit value.
-// Avoids issues when filtering the deprecated `query_string` hook.
-function amp_force_query_var_value( $query_vars ) {
-	if ( isset( $query_vars[ AMP_QUERY_VAR ] ) && '' === $query_vars[ AMP_QUERY_VAR ] ) {
-		$query_vars[ AMP_QUERY_VAR ] = 1;
-	}
-	return $query_vars;
-}
-
-function amp_maybe_add_actions() {
-	if ( ! is_singular() || is_feed() ) {
-		return;
-	}
-
-	$is_amp_endpoint = is_amp_endpoint();
+function amp_add_actions() {
 
-	// Cannot use `get_queried_object` before canonical redirect; see https://core.trac.wordpress.org/ticket/35344
-	global $wp_query;
-	$post = $wp_query->post;
-
-	$supports = post_supports_amp( $post );
-
-	if ( ! $supports ) {
-		if ( $is_amp_endpoint ) {
-			wp_safe_redirect( get_permalink( $post->ID ) );
-			exit;
-		}
+	if ( is_feed()) {
 		return;
 	}
 
-	if ( $is_amp_endpoint ) {
-		amp_prepare_render();
+	if (get_option('amp_canonical') ) {
+		CanonicalModeActions::add_actions();
 	} else {
-		amp_add_frontend_actions();
+		PairedModeActions::add_actions();
 	}
 }
 
-function amp_load_classes() {
-	require_once( AMP__DIR__ . '/includes/class-amp-post-template.php' ); // this loads everything else
-}
-
 function amp_add_frontend_actions() {
-	require_once( AMP__DIR__ . '/includes/amp-frontend-actions.php' );
-}
-
-function amp_add_post_template_actions() {
-	require_once( AMP__DIR__ . '/includes/amp-post-template-actions.php' );
-	require_once( AMP__DIR__ . '/includes/amp-post-template-functions.php' );
-}
-
-function amp_prepare_render() {
-	add_action( 'template_redirect', 'amp_render' );
-}
-
-function amp_render() {
-	$post_id = get_queried_object_id();
-	amp_render_post( $post_id );
-	exit;
+	require_once(AMP__DIR__ . '/includes/actions/amp-frontend-actions.php');
 }
 
-function amp_render_post( $post_id ) {
-	$post = get_post( $post_id );
-	if ( ! $post ) {
-		return;
-	}
-
-	amp_load_classes();
-
-	do_action( 'pre_amp_render_post', $post_id );
-
-	amp_add_post_template_actions();
-	$template = new AMP_Post_Template( $post_id );
-	$template->load();
-}
+add_action( 'plugins_loaded', 'AMPUtils::_amp_bootstrap_customizer', 9 );
 
 /**
- * Bootstraps the AMP customizer.
- *
- * If the AMP customizer is enabled, initially drop the core widgets and menus panels. If the current
- * preview page isn't flagged as an AMP template, the core panels will be re-added and the AMP panel
- * hidden.
- *
- * @internal This callback must be hooked before priority 10 on 'plugins_loaded' to properly unhook
- *           the core panels.
- *
- * @since 0.4
+ * Inject link to AMP version of a post to the REST API posts endpoint
+ * @param $response
+ * @param $post
+ * @return mixed
  */
-function _amp_bootstrap_customizer() {
-	/**
-	 * Filter whether to enable the AMP template customizer functionality.
-	 *
-	 * @param bool $enable Whether to enable the AMP customizer. Default true.
-	 */
-	$amp_customizer_enabled = apply_filters( 'amp_customizer_is_enabled', true );
-
-	if ( true === $amp_customizer_enabled ) {
-		amp_init_customizer();
+function amp_add_link_to_rest_response( $response, $post ) {
+	if ( ! post_supports_amp( $post ) ) {
+		return $response;
 	}
-}
-add_action( 'plugins_loaded', '_amp_bootstrap_customizer', 9 );
-
-/**
- * Redirects the old AMP URL to the new AMP URL.
- * If post slug is updated the amp page with old post slug will be redirected to the updated url.
- *
- * @param  string $link New URL of the post.
- *
- * @return string $link URL to be redirected.
- */
-function amp_redirect_old_slug_to_new_url( $link ) {
 
-	if ( is_amp_endpoint() ) {
-		$link = trailingslashit( trailingslashit( $link ) . AMP_QUERY_VAR );
-	}
+	$response->add_link( 'amphtml', amp_get_permalink( $post->ID ) );
 
-	return $link;
+	return $response;
 }
+add_filter( 'rest_prepare_post', 'amp_add_link_to_rest_response', 10, 2 );
+
+// TODO (@amedina): Check the removal of wpautop
+// Stop WP adding extra <p> </p> to your pages' content
+remove_filter( 'the_content', 'wpautop' );
+
+

includes/actions/amp-canonical-index-actions.php

@@ -0,0 +1,130 @@
+<?php
+
+require_once(AMP__DIR__ . '/includes/content/amp-content-generator.php');
+require_once(AMP__DIR__ . '/post-processing/class-amp-postprocessing.php');
+
+class AMPCanonicalIndexActions
+{
+	static $amp_posts;
+	static $current;
+	static $is_processing;
+
+	public static function init() {
+		self:$amp_posts = array();
+		add_action( 'the_post', array( __CLASS__, 'prepare_content' ));
+		add_action( 'the_content', array( __CLASS__, 'the_content_filter'), 99999 );
+	}
+
+	public static function the_content_filter($content ) {
+		// Avoid infinite loops when calling amp_canonical_retrieve_content
+		if (self::$is_processing ) {
+			return $content;
+		}
+		//return self::$current->get_amp_content();
+		$post = get_post();
+		return self::$amp_posts[ $post->ID ]->get_amp_content();
+	}
+
+	public static function prepare_content( $post ) {
+		if ( !isset( self::$amp_posts[ $post->ID ] ) ) {
+			self::$is_processing = true;
+			self::$amp_posts[ $post->ID ] = AMPContentGenerator::amp_canonical_retrieve_content( $post );
+			self::$is_processing = false;
+		}
+		self::$current = self::$amp_posts[ $post->ID ];
+	}
+
+	public static function deregister_scripts() {
+		wp_deregister_script( 'wp_embed');
+	}
+
+	public static function add_boilerplate_css() {
+		?>
+		<style amp-boilerplate>body{-webkit-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-moz-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-ms-animation:-amp-start 8s steps(1,end) 0s 1 normal both;animation:-amp-start 8s steps(1,end) 0s 1 normal both}@-webkit-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-moz-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-ms-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-o-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}</style><noscript><style amp-boilerplate>body{-webkit-animation:none;-moz-animation:none;-ms-animation:none;animation:none}</style></noscript>
+		<?php
+	}
+
+	public static function add_general_scripts() {
+		$amp_runtime_script = 'https://cdn.ampproject.org/v0.js';
+
+		// Always include AMP form & analytics, as almost every template includes
+		// a search form and is tracking page views
+		$scripts = array_merge(
+			array('amp-form' => 'https://cdn.ampproject.org/v0/amp-form-0.1.js'),
+			array('amp-analytics' => 'https://cdn.ampproject.org/v0/amp-analytics-0.1.js')
+		);
+
+		foreach ( $scripts as $element => $script) : ?>
+			<script custom-element="<?php echo esc_attr( $element ); ?>" src="<?php echo esc_url( $script ); ?>" async></script>
+		<?php endforeach; ?>
+		<script src="<?php echo esc_url( $amp_runtime_script ); ?>" async></script>
+		<?php
+	}
+
+	public static function add_scripts($dom) {
+
+		$scripts = array();
+		// Flatten the arrays of scripts
+		foreach ( self::$amp_posts as $amp_post) {
+			$amp_scripts = $amp_post->get_amp_scripts();
+			// Use an associative array for dedupping scripts
+			foreach ($amp_scripts as $element => $amp_script) {
+				$scripts[ $element ] = $amp_script;
+			}
+		}
+
+		$head = $dom->getElementsByTagName('head')->item(0);
+		foreach ( $scripts as $element => $script) {
+			$custom_script = $dom->createElement( 'script');
+			$custom_script->setAttribute('async', '');
+			$custom_script->setAttribute('custom-element', esc_attr( $element ));
+			$custom_script->setAttribute('src', esc_url( $script ));
+			$head->appendChild($custom_script);
+		}
+	}
+
+	public static function add_canonical($dom) {
+
+		$head = $dom->getElementsByTagName('head')->item(0);
+		$link = $dom->createElement( 'link');
+		$link->setAttribute('rel', 'canonical');
+		$link->setAttribute('href', esc_url( get_site_url() ) );
+		$head->appendChild($link);
+	}
+
+	public static function postprocess_index_html( $html ) {
+		$dom = new DOMDocument();
+		libxml_use_internal_errors(true);
+		$dom->loadHTML($html);
+		libxml_use_internal_errors(false);
+
+		self::add_scripts($dom);
+		self::add_canonical($dom);
+
+		// Add amp attribute to html tag
+		AMP_Postprocessing::add_amp_attr($dom);
+		// Eliminate 3p JS
+		AMP_Postprocessing::eliminate_3p_js($dom);
+		// Eliminate external stylesheets
+		AMP_Postprocessing::eliminate_ext_css($dom);
+		// Set meta viewport
+		AMP_Postprocessing::set_meta_viewport($dom);
+		// Eliminate non-amp-custom Stylesheets
+		AMP_Postprocessing::eliminate_non_amp_custom_styles($dom);
+		// Inline theme CSS
+		AMP_Postprocessing::inline_theme_css($dom);
+		// AMP Custom-header img
+		AMP_Postprocessing::amp_custom_header_img($dom);
+		// Remove styled SVGs
+		AMP_Postprocessing::remove_styled_svgs($dom);
+		// Save new HTML contents
+		$amp_html = $dom->saveHTML();
+
+		return $amp_html;
+	}
+}
+
+AMPCanonicalIndexActions::init();
+add_action( 'wp_head', 'AMPCanonicalIndexActions::add_general_scripts' );
+add_action( 'wp_head', 'AMPCanonicalIndexActions::add_boilerplate_css' );
+add_action( 'wp_footer', 'AMPCanonicalIndexActions::deregister_scripts' );