Code Snippet: Consent for External Content

<?php
/*
Plugin Name:  MA Content Consent
Description:  Shortcode for requesting user consent before loading external content.
Author:       <a href="https://www.altmann.de/">Matthias Altmann</a>
Project:      Code Snippet: MA Content Consent
Version:      1.1.2
Plugin URI:   https://www.altmann.de/en/blog-en/code-snippet-shortcode-content-consent/
Description:  en: https://www.altmann.de/en/blog-en/code-snippet-consent-for-external-content/
              de: https://www.altmann.de/blog/code-snippet-zustimmung-fuer-externe-inhalte/
Copyright:    © 2021-2023, Matthias Altmann



Version History:
Date		Version		Description
--------------------------------------------------------------------------------------------------------------
2023-02-01	1.1.2		Changes:
						- Added Finnish translations for notice text and button label
						- Changed button tag from <a> to <span> to avoid Lighthouse SEO warning "Links not crawlable"
						Fixes:
						- Support for Oxygen Repeater (due to numbered IDs)
						  (Thanks to André Slotta for reporting and supporting with code adaptions)
2022-11-15	1.1.1		Changes:
						- Added Japanese translations for notice text and button label
						  (Thanks to Viorel-Cosmin Miron)
						- Added support for WPML
						  (Thanks to Viorel-Cosmin Miron)
						  Please note there's a WPML bug preventing the creation a policy link with the correct language
						  (https://wpml.org/forums/topic/get_the_privacy_policy_link-should-be-translated/#post-8153387) 
						Fixes:
						- Support for UTF-8 content in JS base64 decoding
						  (Thanks to Tobias Przybilla for reporting)
2022-10-21	1.1.0		Changes:
						- Added new shortcode parameters block-class, text-class, button-class
						- Migrated JavaScript from jQuery to vanilla JS (ES6) to eliminate jQuery dependency.
						  (Thanks to André Slotta for the provided code sample)
						Fixes:
						- Removed double '.' for German GDPR text.
						  (Thanks to Tobias Maximilian Hietsch for reporting)
2022-02-04	1.0.1		- Added Dansk translations for notice text and button label
						  (Thanks to Theis L. Soelberg)
						- Evaluating nested shortcodes
						  (Thanks to Anja Kretzer)
2022-02-03	1.0.0		Initial release as Code Snippet
2021-12-29	0.0.1		Initial version for client project
--------------------------------------------------------------------------------------------------------------
*/

if (!class_exists('MA_Content_Consent')) :

class MA_Content_Consent {
	const TITLE							= 'MA Content Consent';
	const SLUG							= 'ma-content-consent';
	const VERSION						= '1.1.2';


	// ===== CONFIGURATION ==============================================================================================
	public static $timing				= false; 	// Write timing info to wordpress debug.log if WP_DEBUG enabled		
	public static $debug				= false; 	// Write debug info to wordpress debug.log if WP_DEBUG enabled	

	private static $default_consent_text = [ 		// consent text in different languages
		'da' => ['Når du har trykket, vil indholdet blive hentet fra eksterne servere. Se vores %s for flere informationer.','privatlivspolitik'],
		'de' => ['Bei Klick wird dieser Inhalt von externen Servern geladen. Details siehe %s.', 'Datenschutzerklärung'],
		'en' => ['When clicked, this content is loaded from external servers. See our %s for details.', 'privacy policy'],
		'es' => ['Al hacer clic, este contenido se carga desde servidores externos. Consulte la %s para más detalles.', 'política de privacidad'],
		'fi' => ['Kun tätä sisältöä napsautetaan, se ladataan ulkoisilta palvelimilta. Lisätietoja on %s.','tietosuojaselosteessa'],
		'fr' => ['En cliquant, ce contenu est chargé depuis des serveurs externes. Voir la %s.', 'politique de confidentialité'], 
		'hu' => ['Ha rákattint, ez a tartalom külső szerverekről töltődik be. A részletekért olvassa el az %s oldalt.', 'Adatkezelési Tájékoztatót'],
		'it' => ['Quando viene cliccato, questo contenuto viene caricato da server esterni. Vedere %s per i dettagli.', 'l\'informativa sulla privacy'],
		'ja' => ['クリックすると、以下のコンテンツが外部サーバーから読み込まれます。弊社のプライバシーポリシーの詳細は、%s', 'プライバシーポリシー'],
	]; 
	private static $default_button_text = [ 		// button text in different languages
		'da' => 'Indlæs eksternt indhold',
		'de' => 'Externen Inhalt laden',
		'en' => 'Load external content',
		'es' => 'Cargar contenido externo',
		'fi' => 'Lataa ulkoista sisältöä',
		'fr' => 'Charger le contenu externe', 
		'hu' => 'Külső tartalom betöltése',
		'it' => 'Caricare il contenuto esterno',
		'ja' => '外部のコンテンツを読み込ませます。',
	]; 

	//-------------------------------------------------------------------------------------------------------------------
	public static function init() {
		$st = microtime(true);

		add_shortcode('ma-content-consent', [__CLASS__, 'shortcode']);

		$et = microtime(true);
		if (WP_DEBUG && self::$timing) {error_log(sprintf('%s%s::%s() Timing: %.5f sec.', '', __CLASS__, __FUNCTION__, $et-$st));}
	}
	//-------------------------------------------------------------------------------------------------------------------
	private static function get_current_language(){
		$retval = get_locale();
		// Is Polylang available? 
		if (function_exists('pll_current_language')) {$retval = pll_current_language();}
		elseif (function_exists('wpml_current_language')) {$retval = wpml_current_language();}
		$retval = str_replace('_','-',$retval);
		$retval = explode('-',@$retval)[0];
		return $retval;
	}
	//-------------------------------------------------------------------------------------------------------------------
	private static function get_privacy_policy_link($text) {
		// return a link to the privacy policy (if configured) or just the passed text
		$pplink = get_the_privacy_policy_link();
		return  $pplink ? $pplink : $text; 
	}

	//-------------------------------------------------------------------------------------------------------------------
	public static function shortcode($atts, $content = '') {
		$st = microtime(true);
		$lang = self::get_current_language();
		if (!is_array($atts)) $atts = [];
		
		// fix Gutenberg content: remove </p> ... <p>
		$content = preg_replace('/^<\/p>[ \r\n]*/','',$content); // remove leading </p> tag, spaces, line breaks from shortcode start tag
		$content = preg_replace('/[ \r\n]*<p>$/','',$content); // remove trailing line breaks, spaces, <p> tag from shortcode end tag
		// evaluate nested shortcodes
		$content = do_shortcode($content);

		// get defaults for unspecified atts
		$atts = (object)array_merge([
			'slug'					=> self::SLUG,
			'id'					=> uniqid(self::SLUG . '-'),
			'block-style'			=> '',
			'block-class'			=> '',
			'text'					=> isset(self::$default_consent_text[$lang]) 
										? sprintf(self::$default_consent_text[$lang][0],self::get_privacy_policy_link(self::$default_consent_text[$lang][1])) 
										: sprintf(self::$default_consent_text['en'][0],self::get_privacy_policy_link(self::$default_consent_text['en'][1])),
			'text-style'			=> '',
			'text-class'			=> '',
			'button-text'			=> self::$default_button_text[$lang] ?? self::$default_button_text['en'],
			'button-style'			=> '',
			'button-class'			=> '',
			'background-image'		=> null,
			'contentb64'			=> base64_encode($content),
		], $atts);
		$atts->{'background-style'} = $atts->{'background-image'} ? 'background-image:url('.$atts->{'background-image'}.'); background-size:cover; background-position:center center;' : '';

		$atts->{'text'} = str_replace('{privacy-policy-url}', get_privacy_policy_url(), $atts->{'text'});
		$atts->{'text'} = str_replace('{privacy-policy-link}', get_the_privacy_policy_link(), $atts->{'text'});

		// base64 decode supporting UTF-8 from https://stackoverflow.com/questions/30106476/using-javascripts-atob-to-decode-base64-doesnt-properly-decode-utf-8-strings#answer-30106551
		$html = <<<END_OF_HTML
		<div id="{$atts->id}" class="{$atts->slug} {$atts->{'block-class'}}" style="display:flex; flex-direction:column; justify-content:center; align-content:center; background-color:#efefef; border: 1px solid lightgray; padding:1em; width: 100%; {$atts->{'background-style'}} {$atts->{'block-style'}} ">
			<div style="text-align:center">
				<p class="{$atts->slug}__text {$atts->{'text-class'}}" style="font-size:.7em; {$atts->{'text-style'}}">{$atts->{'text'}}</p>
				<span id="{$atts->id}__button" class="wp-block-button__link {$atts->slug}__button {$atts->{'button-class'}}" style="display:inline-block; {$atts->{'button-style'}}">{$atts->{'button-text'}}</span>
			</div>
			<div id="{$atts->id}__content" class="{$atts->slug}__content" style="display:none">{$atts->contentb64}</div>
			<script>
			document.querySelector('[id^="{$atts->id}__button"]').addEventListener('click',function(){
				let consent = this.closest('div.ma-content-consent');
				let b64 = consent.querySelector('.ma-content-consent__content').innerText;
				let content = decodeURIComponent(atob(b64).split('').map(function(c) {
					return '%'+('00'+c.charCodeAt(0).toString(16)).slice(-2);
				}).join(''));
				consent.outerHTML = content;
			});
			</script>
		</div>
END_OF_HTML;

		$et = microtime(true);
		if (WP_DEBUG && self::$timing) {error_log(sprintf('%s%s::%s() Timing: %.5f sec.', '-> ', __CLASS__, __FUNCTION__, $et-$st));}
		return $html;
	}
}

//===================================================================================================================
// Initialize

// Warn about incompatibilities (currently none)
add_action('wp_loaded',function(){
	if (is_admin()) {
		if (!isset($GLOBALS['MA_Content_Consent_Incompatibilities'])) {$GLOBALS['MA_Content_Consent_Incompatibilities'] = [];}
		if (count($GLOBALS['MA_Content_Consent_Incompatibilities'])) {
			if (WP_DEBUG && (MA_Content_Consent::$debug || MA_Content_Consent::$timing)) 
				{error_log('MA_Content_Consent / Incompatibilities: '.print_r($GLOBALS['MA_Content_Consent_Incompatibilities'],true));}
			add_action('admin_notices', function(){
				if (WP_DEBUG ) {error_log('MA_Content_Consent / Incompatibilities: '.print_r($GLOBALS['MA_Content_Consent_Incompatibilities'],true));}
				$implementation = basename(__FILE__) == 'ma-content-consent.php' ? 'Plugin' : 'Code Snippet';
				echo '<div class="notice notice-warning xis-dismissible">
						<p>The '.$implementation.'  "MA Content Consent" is skipped: '.implode(' or ',$GLOBALS['MA_Content_Consent_Incompatibilities']).'</p>
					</div>';
			});
		}
	}
}, 1000); 

add_action('wp_loaded',function(){
	if (count($GLOBALS['MA_Content_Consent_Incompatibilities']??[])) return;
	if (wp_doing_ajax()) 		return; 	// don't run for AJAX requests
	if (wp_doing_cron()) 		return; 	// don't run for CRON requests
	if (wp_is_json_request()) 	return; 	// don't run for JSON requests
	if (is_favicon()) 			return; 	// don't run for favicon request
	if (($_SERVER['QUERY_STRING']??'') == 'service-worker')			return;	// don't run for service-worker
	if (($_SERVER['REQUEST_URI']??'') == '/favicon.ico')			return;	// don't run for favicon
	if ((strpos($_SERVER['REQUEST_URI']??'','/wp-content/') === 0))	return;	// don't run for dynamic wp-content file
	
	if (is_admin()) {
		global $pagenow;
		if (	($pagenow != 'post-new.php') 
		&& 	(	($pagenow != 'post.php') || ($pagenow == 'post.php' && (($_REQUEST['action']??null) != 'edit'))	) 
		) return; // only load on specific requests where Gutenberg is involved
	}
		
	$implementation = basename(__FILE__) == 'ma-content-consent.php' ? 'Plugin' : 'Code Snippet';
	if (WP_DEBUG && (MA_Content_Consent::$debug || MA_Content_Consent::$timing)) 
		{error_log(sprintf('MA_Content_Consent: Initializing %s for request URI="%s" action="%s"', $implementation, $_SERVER['REQUEST_URI']??'', $_REQUEST['action']??''));}

	MA_Content_Consent::init();

}, 1200); 
	
endif;