Wordpress Backend Logger

BackendLogger.php

<?php
namespace tm;

/**
 * @see https://gist.github.com/vollyimnetz/3670de82fd2b967722875627c27ea446
 */
class BackendLogger {

	private static $secondsToRelaod = 5;
	private static $version = '1.2';

	public static function init() {
		self::$secondsToRelaod = apply_filters('tm_backendlogger_seconds_to_reload', 5);
		add_action( 'init', [self::class,'validateAndRegistrate']);
		add_action( 'rest_api_init', [self::class, 'initRest']);
	}

	public static function validateAndRegistrate() {
		add_action( 'admin_menu', [self::class,'registerMenu' ]);
		add_action( 'admin_enqueue_scripts', [self::class,'enqueueAdminScripts' ]);
	}

	public static function registerMenu() {
		add_submenu_page( 'tools.php', 'Backend Logger', 'Backend Logger', 'manage_options', 'tm_backend_logger', [self::class, 'htmlOutput']);
	}

	/**
	 * Settings page display callback.
	 */
	public static function htmlOutput() {
		$noenceField = 'tm_backend_logger_noence';
		$noenceKey = 'tm_backend_logger_noence_0298540v00s09öä1sdf9';

		?>
		<div class="wrap">
			<h2>Backend Logger <?php echo '(v'.self::$version.')'?></h2>
			<?php if(empty(WP_DEBUG_LOG)) : ?>
				<h3>Fehlerhaftes Setup?</h3>
				<p>Es sieht so aus, als ob die PHP Konstante "WP_DEBUG_LOG" nicht korrekt gesetzt wurde. Hier der typische Standardcode. Achten Sie darauf die wp-debug.log nicht in einen vom Internet abrufbaren Ort abzulegen (z.B. unterhalb des Domaineinstiegspunktes).</p>
				<textarea class="large-text code" rows="5">define('WP_DEBUG', true);
define('WP_DEBUG_DISPLAY', false);
define('WP_DEBUG_LOG', __DIR__.'/wp-debug.log');
@ini_set('display_errors', 0);
				</textarea>
				<hr />
			<?php endif; ?>
			<div id="tm_backend_logger">
				<div class="errorsWrapper">
					<h3>Fehler bei der Log Abfrage</h3>
					<div class="errors"></div>
					<button class="button doDeleteErrors" type="button">zurücksetzen</button>
				</div>
				<div class="logsWrapper">
					<h3>PHP Debug Log (neuste zuerst)</h3>
					<fieldset>
						<label for="tm_backend_logger_autosync">
							<input type="checkbox" id="tm_backend_logger_autosync" name="tm_backend_logger_autosync" value="1" checked>
							Automatisch alle <?php echo self::$secondsToRelaod; ?> Sekunden aktualisieren?
						</label>
					</fieldset>
					<p>
						<button class="button doSyncNow" type="button">jetzt aktualisieren</button>
						<button class="button doTruncate" type="button">Log-File leeren</button>
					</p>
					<div class="logs"></div>
				</div>
			</div>
		</div>
		<script>
		jQuery(function($) {
			var settings = {
				root : '<?php echo esc_url_raw( rest_url() ) ?>',
				nonceRest : '<?php echo wp_create_nonce( 'wp_rest' ) ?>',
			};
			var errors = [];
			var log = [];
			var secondsToReload = <?php echo self::$secondsToRelaod; ?>;
			var printedHashes = [];

			jQuery('#tm_backend_logger .doDeleteErrors').click(() => {
				console.log('errors zurückgesetzt');
				errors = [];
				printErrors();
			});
			jQuery('#tm_backend_logger .doSyncNow').click(() => {
				getLog(false);
			});
			jQuery('#tm_backend_logger .doTruncate').click(() => {
				doTruncate();
			});

			function doTruncate() {
				jQuery.ajax({
						method: 'GET',
						url: settings.root+'backendlogger/v1/truncate',
						headers: { 'X-WP-Nonce': settings.nonceRest },
					})
					.success(result => {
						reset();
						getLog(false);
					})
					.fail(() => {
						addError('Beim Laden des Logs ist es zu einem Fehler gekommen.');
					});
			}

			function reset() {
				errors = [];
				log = [];
				printedHashes = [];
				printErrors();
				jQuery('#tm_backend_logger').find('.logs').empty();
			}

			function getLog(doTimeout = true) {
				jQuery.ajax({
						method: 'GET',
						url: settings.root+'backendlogger/v1/read',
						headers: { 'X-WP-Nonce': settings.nonceRest },
					})
					.success(result => {
						handleLog(result);
						if(doTimeout) setTimeout(() => { getLog( document.getElementById('tm_backend_logger_autosync').checked ); }, secondsToReload*1000 );
					})
					.fail(() => {
						addError('Beim Laden des Logs ist es zu einem Fehler gekommen.');
						if(doTimeout) setTimeout(() => { getLog( document.getElementById('tm_backend_logger_autosync').checked ); }, secondsToReload*1000 );
					});
			}

			function handleLog(data) {
				if(data.logs) {
					let baseLogs = jQuery('#tm_backend_logger').find('.logs');
					data.logs.forEach(elem => {
						if(!printedHashes.includes( elem.hash ) ) {
							printedHashes.unshift( elem.hash );
							baseLogs.prepend('<div class="logEntry"><div class="time">'+formatDate(new Date( elem.timestamp*1000 ))+' ('+(elem.time)+')</div><div class="text">'+optimizeErrorOutput(elem.text)+'</div></div>');
						}
					});
					//window.scrollTo(0,document.body.scrollHeight);
				}
			}

			function addError(text) {
				errors.push({
					time: new Date(),
					text: text,
				});
				while(errors.length>3) {
					errors.shift();
				}
				printErrors();
			}

			function printErrors() {
				let baseErrors = jQuery('#tm_backend_logger').find('.errors');
				baseErrors.empty();
				if(errors.length===0) {
					jQuery('#tm_backend_logger .errorsWrapper').hide();
				} else {
					jQuery('#tm_backend_logger .errorsWrapper').show();
				}
				errors.forEach(elem => {
					baseErrors.prepend('<div class="errorEntry"><div class="time">'+formatDate(elem.time)+'</div><div class="text">'+elem.text+'</div></div>');
				});
				//window.scrollTo(0,document.body.scrollHeight);
			}

			function optimizeErrorOutput(text) {
				text = text.replaceAll("\n","<br>");
				return text;
			}


			function formatDate(date) {
				let year = date.getFullYear();
				let month = ('0'+(date.getMonth()+1)).slice(-2);
				let day = ('0'+date.getDate()).slice(-2);
				let hour = ('0'+date.getHours()).slice(-2);
				let minute = ('0'+date.getMinutes()).slice(-2);
				let second = ('0'+date.getSeconds()).slice(-2);

				let result = `${year}-${month}-${day} ${hour}:${minute}:${second}`;

				return result;
			}

			getLog();
			printErrors();
		});
		</script>
		<style type="text/css">
		#tm_backend_logger .errors { border-bottom: 3px dashed rgba(0,0,0,0.2); }
		#tm_backend_logger .errorsWrapper .button { margin:.5em 0 1em; }
		#tm_backend_logger .errors .errorEntry .time { font-size:.9em; font-weight:bold; }
		#tm_backend_logger .errors,
		#tm_backend_logger .logs { background:#fff; }
		#tm_backend_logger .errors .errorEntry,
		#tm_backend_logger .logs .logEntry { border-top: 1px solid rgba(0,0,0,0.2); padding: 1.5em 2em; overflow-x: auto; white-space: nowrap; }
		#tm_backend_logger .logs .logEntry .time { font-size:.8em; font-weight:bold; }
		#tm_backend_logger .logs .logEntry .text { white-space: break-spaces; }
		</style>
		<?php
	}


	public static function enqueueAdminScripts($hook) {
		if( $hook !== 'tools_page_tm_backend_logger' ) {
			return;
		}
		wp_enqueue_script( 'jquery');
	}


	public static function initRest() {
		//add endpoint customeranalysis
		register_rest_route( 'backendlogger/v1', 'read', [
			'methods' => 'GET',
			'callback' => [self::class,'rest_backendlogger'],
			'schema' => null,
			'permission_callback' => [self::class,'checkRestPermission']
		]);
		register_rest_route( 'backendlogger/v1', 'truncate', [
			'methods' => 'GET',
			'callback' => [self::class,'rest_backendlogger_truncate'],
			'schema' => null,
			'permission_callback' => [self::class,'checkRestPermission']
		]);
	}

	public static function checkRestPermission() {
		if(!current_user_can('manage_options')) {
			error_log('Try to access without permission (API).');
			return false;
		}
		return true;
	}


	public static function rest_backendlogger_truncate() {
		$pathToLogFile = WP_DEBUG_LOG;
		if(!file_exists($pathToLogFile)) {
			return ['error' => 'Log File can not be found.'];
		}
		$fp = fopen($pathToLogFile, "w");
		fclose($fp);
		return ['result' => 'OK'];
	}


	public static function rest_backendlogger(\WP_REST_Request $request) {
		$pathToLogFile = WP_DEBUG_LOG;
		if(!file_exists($pathToLogFile)) {
			return ['error' => 'Log File can not be found.'];
		}
		$logFileContent = self::readLastLines($pathToLogFile, \apply_filters('tm_backend_logger_last_x_lines', 1000));
		//optimize for the regex to match perfect
		//-> add line break at start
		//-> add line break at end and an "["
		$logFileContent = "\n".$logFileContent."\n[";

		//@see https://regex101.com/r/ZMdC0c/1
		$re = '/\[(\d\d-\w\w\w-\d\d\d\d \d\d:\d\d:\d\d UTC)\]([\s\S]+?(?=\n\[))/m';
		preg_match_all($re, $logFileContent, $matches, PREG_SET_ORDER, 0);

		$result = [];
		if(!empty($matches) && is_array($matches)) {
			foreach($matches as $values) {
				if(sizeof($values)!==3) continue;
				$date = \DateTime::createFromFormat('d-M-Y H:i:s \U\T\C',$values[1]);
				$tmp = [
					'hash' => '',
					'time' => $values[1],
					'text' => htmlentities( trim($values[2]) ),
					'timestamp' => $date->format('U'),
					'date' => $date,
				];
				$tmp['hash'] = md5($tmp['time'].$tmp['text']);
				$result[] = $tmp;
			}
		}

		return ['logs' => $result];
	}

	private static function readLastLines($filename, $num, $reverse = false) {
		if(filesize($filename)===0) return '';
		$file = new \SplFileObject($filename, 'r');
		$file->seek(PHP_INT_MAX);
		$last_line = $file->key();
		$first_line = $last_line - $num < 0 ? 0 : $last_line - $num;
		$lines = new \LimitIterator($file, $first_line, $last_line);
		$arr = iterator_to_array($lines);
		if($reverse) $arr = array_reverse($arr);
		return implode('', $arr);
	}
}
BackendLogger::init();