Experimental: Add sandboxing levels

.phpstorm.meta.php

@@ -48,6 +48,7 @@
 			'reader_theme_support_features'      => \AmpProject\AmpWP\ReaderThemeSupportFeatures::class,
 			'rest.options_controller'            => \AmpProject\AmpWP\OptionsRESTController::class,
 			'rest.validation_counts_controller'  => \AmpProject\AmpWP\Validation\ValidationCountsRestController::class,
+			'sandboxing_levels'                  => \AmpProject\AmpWP\SandboxingLevels::class,
 			'save_post_validation_event'         => \AmpProject\AmpWP\Validation\SavePostValidationEvent::class,
 			'server_timing'                      => \AmpProject\AmpWP\Instrumentation\ServerTiming::class,
 			'site_health_integration'            => \AmpProject\AmpWP\Admin\SiteHealth::class,

assets/src/settings-page/template-modes.js

@@ -101,10 +101,10 @@ function getReaderNotice( selected ) {
  * @param {boolean} props.focusReaderThemes Whether the reader themes drawer should be opened and focused.
  */
 export function TemplateModes( { focusReaderThemes } ) {
-	const { editedOptions } = useContext( Options );
+	const { editedOptions, updateOptions } = useContext( Options );
 	const { selectedTheme, templateModeWasOverridden } = useContext( ReaderThemes );
 
-	const { theme_support: themeSupport } = editedOptions;
+	const { theme_support: themeSupport, sandboxing_level: sandboxingLevel } = editedOptions;
 
 	const { readerNoticeSmall, readerNoticeLarge } = useMemo(
 		() => getReaderNotice( READER === themeSupport ),
@@ -138,6 +138,69 @@ export function TemplateModes( { focusReaderThemes } ) {
 						</AMPNotice>
 					)
 				}
+				{
+					sandboxingLevel && (
+						<fieldset>
+							<h4 className="title">
+								{ __( 'Sandboxing Level (Experimental)', 'amp' ) }
+							</h4>
+							<p>
+								{ __( 'Try out a more flexible AMP by generating pages that use AMP components without requiring AMP validity! By selecting a sandboxing level, you are indicating the minimum degree of sanitization. For example, if you selected level 1 but have a page without any POST form and no custom scripts, it will still be served as valid AMP, the same as if you had selected level 3.', 'amp' ) }
+							</p>
+							<ol>
+								<li>
+									<input
+										type="radio"
+										id="sandboxing-level-1"
+										checked={ 1 === sandboxingLevel }
+										onChange={ () => {
+											updateOptions( { sandboxing_level: 1 } );
+										} }
+									/>
+									<label htmlFor="sandboxing-level-1">
+										<strong>
+											{ __( 'Loose:', 'amp' ) }
+										</strong>
+										{ ' ' + __( 'Do not remove any AMP-invalid markup by default, including custom scripts. CSS tree-shaking is disabled.', 'amp' ) }
+									</label>
+								</li>
+								<li>
+									<input
+										type="radio"
+										id="sandboxing-level-2"
+										checked={ 2 === sandboxingLevel }
+										onChange={ () => {
+											updateOptions( { sandboxing_level: 2 } );
+										} }
+									/>
+									<label htmlFor="sandboxing-level-2">
+										<strong>
+											{ __( 'Moderate:', 'amp' ) }
+										</strong>
+										{ ' ' + __( 'Remove non-AMP markup, but allow POST forms. CSS tree shaking is enabled.', 'amp' ) }
+									</label>
+								</li>
+								<li>
+									<input
+										type="radio"
+										id="sandboxing-level-3"
+										checked={ 3 === sandboxingLevel }
+										onChange={ () => {
+											updateOptions( { sandboxing_level: 3 } );
+										} }
+									/>
+									<label htmlFor="sandboxing-level-3">
+										<strong>
+											{ __( 'Strict:', 'amp' ) }
+										</strong>
+										{ ' ' + __( 'Require valid AMP.', 'amp' ) }
+									</label>
+								</li>
+
+							</ol>
+						</fieldset>
+					)
+				}
 			</TemplateModeOption>
 			<TemplateModeOption
 				details={ __( 'In Transitional mode the active theme\'s templates are used to generate both the AMP and non-AMP versions of your content, allowing for each canonical URL to have a corresponding (paired) AMP URL. This mode is useful to progressively transition towards a fully AMP-compatible site. Depending on your themes/plugins, a varying level of development work may be required.', 'amp' ) }

includes/amp-helper-functions.php

@@ -870,6 +870,16 @@ function amp_add_generator_metadata() {
 		$content .= sprintf( '; theme=%s', $reader_theme );
 	}
 
+	/**
+	 * Filters content for the AMP meta generator tag.
+	 *
+	 * @since 2.2
+	 * @internal
+	 *
+	 * @param string $content Content.
+	 */
+	$content = apply_filters( 'amp_meta_generator', $content );
+
 	printf( '<meta name="generator" content="%s">', esc_attr( $content ) );
 }
 
@@ -1380,10 +1390,6 @@ function amp_is_dev_mode() {
 			( is_admin_bar_showing() && is_user_logged_in() )
 			||
 			is_customize_preview()
-			||
-			// Force dev mode for Bento since it currently requires the Bento experiment opt-in script.
-			// @todo Remove this once Bento no longer requires an experiment to opt-in. See <https://amp.dev/documentation/guides-and-tutorials/start/bento_guide/?format=websites#enable-bento-experiment>.
-			amp_is_bento_enabled()
 		)
 	);
 }
@@ -1410,26 +1416,6 @@ function amp_is_native_img_used() {
 	return (bool) apply_filters( 'amp_native_img_used', false );
 }
 
-/**
- * Determine whether to allow native `POST` forms without conversion to use the `action-xhr` attribute and use the amp-form component.
- *
- * @since 2.2
- * @link https://github.com/ampproject/amphtml/issues/27638
- *
- * @return bool Whether to allow native `POST` forms.
- */
-function amp_is_native_post_form_allowed() {
-	/**
-	 * Filters whether to allow native `POST` forms without conversion to use the `action-xhr` attribute and use the amp-form component.
-	 *
-	 * @since 2.2
-	 * @link https://github.com/ampproject/amphtml/issues/27638
-	 *
-	 * @param bool $use_native Whether to allow native `POST` forms.
-	 */
-	return (bool) apply_filters( 'amp_native_post_form_allowed', false );
-}
-
 /**
  * Get content sanitizers.
  *
@@ -1474,18 +1460,16 @@ function amp_get_content_sanitizers( $post = null ) {
 		AMP_Theme_Support::TRANSITIONAL_MODE_SLUG === AMP_Options_Manager::get_option( Option::THEME_SUPPORT )
 	);
 
-	$native_img_used           = amp_is_native_img_used();
-	$native_post_forms_allowed = amp_is_native_post_form_allowed();
+	$native_img_used = amp_is_native_img_used();
 
 	$sanitizers = [
-		// The AMP_Script_Sanitizer runs first because based on whether it allows custom scripts
-		// to be kept, it may impact the behavior of other sanitizers. For example, if custom
-		// scripts are kept then this is a signal that tree shaking in AMP_Style_Sanitizer cannot be
-		// performed.
-		AMP_Script_Sanitizer::class            => [],
+		// Embed sanitization must come first because it strips out custom scripts associated with embeds.
 		AMP_Embed_Sanitizer::class             => [
 			'amp_to_amp_linking_enabled' => $amp_to_amp_linking_enabled,
 		],
+		AMP_O2_Player_Sanitizer::class         => [],
+		AMP_Playbuzz_Sanitizer::class          => [],
+
 		AMP_Core_Theme_Sanitizer::class        => [
 			'template'        => get_template(),
 			'stylesheet'      => get_stylesheet(),
@@ -1494,21 +1478,25 @@ function amp_get_content_sanitizers( $post = null ) {
 			],
 			'native_img_used' => $native_img_used,
 		],
+
+		AMP_Comments_Sanitizer::class          => [
+			'comments_live_list' => ! empty( $theme_support_args['comments_live_list'] ),
+		],
+
+		// The AMP_Script_Sanitizer runs here because based on whether it allows custom scripts
+		// to be kept, it may impact the behavior of other sanitizers. For example, if custom
+		// scripts are kept then this is a signal that tree shaking in AMP_Style_Sanitizer cannot be
+		// performed.
+		AMP_Script_Sanitizer::class            => [],
+
 		AMP_Srcset_Sanitizer::class            => [],
 		AMP_Img_Sanitizer::class               => [
 			'align_wide_support' => current_theme_supports( 'align-wide' ),
 			'native_img_used'    => $native_img_used,
 		],
-		AMP_Form_Sanitizer::class              => [
-			'native_post_forms_allowed' => $native_post_forms_allowed,
-		],
-		AMP_Comments_Sanitizer::class          => [
-			'comments_live_list' => ! empty( $theme_support_args['comments_live_list'] ),
-		],
+		AMP_Form_Sanitizer::class              => [],
 		AMP_Video_Sanitizer::class             => [],
-		AMP_O2_Player_Sanitizer::class         => [],
 		AMP_Audio_Sanitizer::class             => [],
-		AMP_Playbuzz_Sanitizer::class          => [],
 		AMP_Object_Sanitizer::class            => [],
 		AMP_Iframe_Sanitizer::class            => [
 			'add_placeholder'    => true,
@@ -1626,8 +1614,27 @@ function amp_get_content_sanitizers( $post = null ) {
 	 */
 	$sanitizers[ AMP_Style_Sanitizer::class ]['allow_transient_caching'] = apply_filters( 'amp_parsed_css_transient_caching_allowed', true );
 
-	// Force layout, style, meta, and validating sanitizers to be at the end.
-	foreach ( [ AMP_Layout_Sanitizer::class, AMP_Style_Sanitizer::class, AMP_Meta_Sanitizer::class, AMP_Tag_And_Attribute_Sanitizer::class ] as $class_name ) {
+	// Force core essential sanitizers to appear at the end at the end, with non-essential and third-party sanitizers appearing before.
+	$expected_final_sanitizer_order = [
+		AMP_Core_Theme_Sanitizer::class, // Must come before script sanitizer since onclick attributes are removed.
+		AMP_Script_Sanitizer::class, // Must come before sanitizers for images, videos, audios, comments, forms, and styles.
+		AMP_Form_Sanitizer::class, // Must come before comments sanitizer.
+		AMP_Comments_Sanitizer::class, // Also must come after the form sanitizer.
+		AMP_Srcset_Sanitizer::class,
+		AMP_Img_Sanitizer::class,
+		AMP_Video_Sanitizer::class,
+		AMP_Audio_Sanitizer::class,
+		AMP_Object_Sanitizer::class,
+		AMP_Iframe_Sanitizer::class,
+		AMP_Gallery_Block_Sanitizer::class,
+		AMP_Block_Sanitizer::class,
+		AMP_Accessibility_Sanitizer::class,
+		AMP_Layout_Sanitizer::class,
+		AMP_Style_Sanitizer::class,
+		AMP_Meta_Sanitizer::class,
+		AMP_Tag_And_Attribute_Sanitizer::class,
+	];
+	foreach ( $expected_final_sanitizer_order as $class_name ) {
 		if ( isset( $sanitizers[ $class_name ] ) ) {
 			$sanitizer = $sanitizers[ $class_name ];
 			unset( $sanitizers[ $class_name ] );