/application/libraries/PhpConsole.php

<?php

/**
 *
 * @see http://code.google.com/p/php-console
 * @author Barbushin Sergey http://linkedin.com/in/barbushin
 * @version 1.1
 * 
 * @desc Sending messages to Google Chrome console
 *
 * You need to install Google Chrome extension:
 * https://chrome.google.com/extensions/detail/nfhmhhlpfleoednkpnnnkolmclajemef
 *
 * All class properties and methods are static because it's required to let
 * them work on script shutdown when FATAL error occurs.
 *
 */
class PhpConsole {

	public static $ignoreRepeatedEvents = false;
	public static $callOldErrorHandler = true;
	public static $callOldExceptionsHandler = true;

	/**
	 * @var PhpConsole
	 */
	protected static $instance;

	protected $handledMessagesHashes = array();
	protected $sourceBasePath;

	protected function __construct($handleErrors, $handleExceptions, $sourceBasePath) {
		if($handleErrors) {
			$this->initErrorsHandler();
		}
		if($handleExceptions) {
			$this->initExceptionsHandler();
		}
		if($sourceBasePath) {
			$this->sourceBasePath = realpath($sourceBasePath);
		}
		$this->initClient();
	}

	public static function start($handleErrors = true, $handleExceptions = true, $sourceBasePath = null) {
		if(!self::$instance) {
			self::$instance = new PhpConsole($handleErrors, $handleExceptions, $sourceBasePath);
		}
	}

	protected function handle(PhpConsoleEvent $event) {
		if(self::$ignoreRepeatedEvents) {
			$eventHash = md5($event->message . $event->file . $event->line);
			if(in_array($eventHash, $this->handledMessagesHashes)) {
				return;
			}
			else {
				$this->handledMessagesHashes[] = $eventHash;
			}
		}
		$this->sendEventToClient($event);
	}

	public function __destruct() {
		self::flushMessagesBuffer();
	}

	/***************************************************************
	CLIENT
	 **************************************************************/

	const clientProtocolCookie = 'phpcslc';
	const serverProtocolCookie = 'phpcsls';
	const serverProtocol = 4;
	const messagesCookiePrefix = 'phpcsl_';
	const cookiesLimit = 50;
	const cookieSizeLimit = 4000;
	const messageLengthLimit = 2500;

	protected static $isEnabledOnClient;
	protected static $isDisabled;
	protected static $messagesBuffer = array();
	protected static $bufferLength = 0;
	protected static $messagesSent = 0;
	protected static $cookiesSent = 0;
	protected static $index = 0;

	protected function initClient() {
		if(self::$isEnabledOnClient === null) {
			self::setEnabledOnServer();
			self::$isEnabledOnClient = self::isEnabledOnClient();
			if(self::$isEnabledOnClient) {
				ob_start();
			}
		}
	}

	protected static function isEnabledOnClient() {
		return isset($_COOKIE[self::clientProtocolCookie]) && $_COOKIE[self::clientProtocolCookie] == self::serverProtocol;
	}

	protected static function setEnabledOnServer() {
		if(!isset($_COOKIE[self::serverProtocolCookie]) || $_COOKIE[self::serverProtocolCookie] != self::serverProtocol) {
			self::setCookie(self::serverProtocolCookie, self::serverProtocol);
		}
	}

	protected function sendEventToClient(PhpConsoleEvent $event) {
		if(!self::$isEnabledOnClient || self::$isDisabled) {
			return;
		}
		$message = array();
		$message['type'] = strpos($event->tags, 'error,') === 0 ? 'error' : 'debug';
		$message['subject'] = $event->type;
		$message['text'] = substr($event->message, 0, self::messageLengthLimit);

		if($event->file) {
			$message['source'] = ($this->sourceBasePath ? preg_replace('!^' . preg_quote($this->sourceBasePath, '!') . '!', '', $event->file) : $event->file) . ($event->line ? ':' . $event->line : '');
		}
		if($event->trace) {
			$traceArray = $this->convertTraceToArray($event->trace, $event->file, $event->line);
			if($traceArray) {
				$message['trace'] = $traceArray;
			}
		}

		self::pushMessageToBuffer($message);

		if(strpos($event->tags, ',fatal')) {
			self::flushMessagesBuffer();
		}
	}

	protected function convertTraceToArray($traceData, $eventFile = null, $eventLine = null) {
		$trace = array();
		foreach($traceData as $call) {
			if((isset($call['class']) && $call['class'] == __CLASS__) || (!$trace && isset($call['file']) && $call['file'] == $eventFile && $call['line'] == $eventLine)) {
				$trace = array();
				continue;
			}
			$args = array();
			if(isset($call['args'])) {
				foreach($call['args'] as $arg) {
					if(is_object($arg)) {
						$args[] = get_class($arg);
					}
					elseif(is_array($arg)) {
						$args[] = 'Array';
					}
					else {
						$arg = var_export($arg, 1);
						$args[] = strlen($arg) > 12 ? substr($arg, 0, 8) . '...\'' : $arg;
					}
				}
			}
			if(isset($call['file']) && $this->sourceBasePath) {
				$call['file'] = preg_replace('!^' . preg_quote($this->sourceBasePath, '!') . '!', '', $call['file']);
			}
			$trace[] = (isset($call['file']) ? ($call['file'] . ':' . $call['line']) : '[internal call]') . ' - ' . (isset($call['class']) ? $call['class'] . $call['type'] : '') . $call['function'] . '(' . implode(', ', $args) . ')';
		}
		$trace = array_reverse($trace);
		foreach($trace as $i => &$call) {
			$call = '#' . ($i + 1) . ' ' . $call;
		}
		return $trace;
	}

	protected static function pushMessageToBuffer($message) {
		$encodedMessageLength = strlen(rawurlencode(json_encode($message)));
		if(self::$bufferLength + $encodedMessageLength > self::cookieSizeLimit) {
			self::flushMessagesBuffer();
		}
		self::$messagesBuffer[] = $message;
		self::$bufferLength += $encodedMessageLength;
	}

	protected static function getNextIndex() {
		return substr(number_format(microtime(1), 3, '', ''), -6) + self::$index++;
	}

	public static function flushMessagesBuffer() {
		if(self::$messagesBuffer) {
			self::sendMessages(self::$messagesBuffer);
			self::$bufferLength = 0;
			self::$messagesSent += count(self::$messagesBuffer);
			self::$messagesBuffer = array();
			self::$cookiesSent++;
			if(self::$cookiesSent == self::cookiesLimit) {
				self::$isDisabled = true;
				$message = array('type' => 'error', 'subject' => 'PHP CONSOLE', 'text' => 'MESSAGES LIMIT EXCEEDED BECAUSE OF COOKIES STORAGE LIMIT. TOTAL MESSAGES SENT: ' . self::$messagesSent, 'source' => __FILE__, 'notify' => 3);
				self::sendMessages(array($message));
			}
		}
	}

	protected static function setCookie($name, $value) {
		if(headers_sent($file, $line)) {
			throw new Exception('setcookie() failed because haders are sent (' . $file . ':' . $line . '). Try to use ob_start()');
		}
		setcookie($name, $value, null, '/');
	}

	protected static function sendMessages($messages) {
		self::setCookie(self::messagesCookiePrefix . self::getNextIndex(), json_encode($messages));
	}

	/***************************************************************
	ERRORS
	 **************************************************************/

	protected $codesTags = array(E_ERROR => 'fatal', E_WARNING => 'warning', E_PARSE => 'fatal', E_NOTICE => 'notice', E_CORE_ERROR => 'fatal', E_CORE_WARNING => 'warning', E_COMPILE_ERROR => 'fatal', E_COMPILE_WARNING => 'warning', E_USER_ERROR => 'fatal', E_USER_WARNING => 'warning', E_USER_NOTICE => 'notice', E_STRICT => 'warning');
	protected $codesNames = array(E_ERROR => 'E_ERROR', E_WARNING => 'E_WARNING', E_PARSE => 'E_PARSE', E_NOTICE => 'E_NOTICE', E_CORE_ERROR => 'E_CORE_ERROR', E_CORE_WARNING => 'E_CORE_WARNING', E_COMPILE_ERROR => 'E_COMPILE_ERROR', E_COMPILE_WARNING => 'E_COMPILE_WARNING', E_USER_ERROR => 'E_USER_ERROR', E_USER_WARNING => 'E_USER_WARNING', E_USER_NOTICE => 'E_USER_NOTICE', E_STRICT => 'E_STRICT');
	protected $notCompitableCodes = array('E_RECOVERABLE_ERROR' => 'warning', 'E_DEPRECATED' => 'warning');
	protected $oldErrorHandler;

	protected function initErrorsHandler() {
		ini_set('display_errors', false);
		ini_set('html_errors', false);
		ini_set('ignore_repeated_errors', self::$ignoreRepeatedEvents);
		ini_set('ignore_repeated_source', self::$ignoreRepeatedEvents);

		foreach($this->notCompitableCodes as $code => $tag) {
			if(defined($code)) {
				$this->codesTags[constant($code)] = $tag;
				$this->codesNames[constant($code)] = $code;
			}
		}

		$this->oldErrorHandler = set_error_handler(array($this, 'handleError'));
		register_shutdown_function(array($this, 'checkFatalError'));
	}

	public function checkFatalError() {
		$error = error_get_last();
		if($error) {
			$this->handleError($error['type'], $error['message'], $error['file'], $error['line']);
		}
	}

	public function handleError($code = null, $message = null, $file = null, $line = null) {
		if(error_reporting() == 0) { // if error has been supressed with an @
			return;
		}
		if(!$code) {
			$code = E_USER_ERROR;
		}

		$event = new PhpConsoleEvent();
		$event->tags = 'error,' . (isset($this->codesTags[$code]) ? $this->codesTags[$code] : 'warning');
		$event->message = $message;
		$event->type = isset($this->codesNames[$code]) ? $this->codesNames[$code] : $code;
		$event->file = $file;
		$event->line = $line;
		$event->trace = debug_backtrace();

		$this->handle($event);

		if(self::$callOldErrorHandler && $this->oldErrorHandler) {
			call_user_func_array($this->oldErrorHandler, array($code, $message, $file, $line));
		}
	}

	/***************************************************************
	EXCEPTIONS
	 **************************************************************/

	protected $oldExceptionsHandler;

	protected function initExceptionsHandler() {
		$this->oldExceptionsHandler = set_exception_handler(array($this, 'handleException'));
	}

	public function handleException(Exception $exception) {
		$event = new PhpConsoleEvent();
		$event->message = $exception->getMessage();
		$event->tags = 'error,fatal,exception,' . get_class($exception);
		$event->type = get_class($exception);
		$event->file = $exception->getFile();
		$event->line = $exception->getLine();
		$event->trace = $exception->getTrace();

		$this->handle($event);

		// TODO: check if need to throw
		if(self::$callOldExceptionsHandler && $this->oldExceptionsHandler) {
			call_user_func($this->oldExceptionsHandler, $exception);
		}
	}

	/***************************************************************
	DEBUG
	 **************************************************************/

	public static function debug($message, $tags = 'debug') {
		if(self::$instance) {
			$event = new PhpConsoleEvent();
			$event->message = $message;
			$event->tags = $tags;
			$event->type = $tags;
			self::$instance->handle($event);
		}
	}
}

class PhpConsoleEvent {
	public $message;
	public $type;
	public $tags;
	public $trace;
	public $file;
	public $line;
}

function debug($message, $tags = 'debug') {
	PhpConsole::debug($message, $tags);
}