Debugger.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         1.2.0
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Error;

use Cake\Log\Log;
use Cake\Utility\Hash;
use Cake\Utility\Security;
use Cake\Utility\String;
use Exception;
use InvalidArgumentException;

/**
 * Provide custom logging and error handling.
 *
 * Debugger overrides PHP's default error handling to provide stack traces and enhanced logging
 *
 * @link          http://book.cakephp.org/2.0/en/development/debugging.html#debugger-class
 */
class Debugger {

/**
 * A list of errors generated by the application.
 *
 * @var array
 */
	public $errors = array();

/**
 * The current output format.
 *
 * @var string
 */
	protected $_outputFormat = 'js';

/**
 * Templates used when generating trace or error strings. Can be global or indexed by the format
 * value used in $_outputFormat.
 *
 * @var string
 */
	protected $_templates = array(
		'log' => array(
			'trace' => '{:reference} - {:path}, line {:line}',
			'error' => "{:error} ({:code}): {:description} in [{:file}, line {:line}]"
		),
		'js' => array(
			'error' => '',
			'info' => '',
			'trace' => '<pre class="stack-trace">{:trace}</pre>',
			'code' => '',
			'context' => '',
			'links' => array(),
			'escapeContext' => true,
		),
		'html' => array(
			'trace' => '<pre class="cake-error trace"><b>Trace</b> <p>{:trace}</p></pre>',
			'context' => '<pre class="cake-error context"><b>Context</b> <p>{:context}</p></pre>',
			'escapeContext' => true,
		),
		'txt' => array(
			'error' => "{:error}: {:code} :: {:description} on line {:line} of {:path}\n{:info}",
			'code' => '',
			'info' => ''
		),
		'base' => array(
			'traceLine' => '{:reference} - {:path}, line {:line}',
			'trace' => "Trace:\n{:trace}\n",
			'context' => "Context:\n{:context}\n",
		)
	);

/**
 * Holds current output data when outputFormat is false.
 *
 * @var string
 */
	protected $_data = array();

/**
 * Constructor.
 *
 */
	public function __construct() {
		$docRef = ini_get('docref_root');

		if (empty($docRef) && function_exists('ini_set')) {
			ini_set('docref_root', 'http://php.net/');
		}
		if (!defined('E_RECOVERABLE_ERROR')) {
			define('E_RECOVERABLE_ERROR', 4096);
		}

		$e = '<pre class="cake-error">';
		$e .= '<a href="javascript:void(0);" onclick="document.getElementById(\'{:id}-trace\')';
		$e .= '.style.display = (document.getElementById(\'{:id}-trace\').style.display == ';
		$e .= '\'none\' ? \'\' : \'none\');"><b>{:error}</b> ({:code})</a>: {:description} ';
		$e .= '[<b>{:path}</b>, line <b>{:line}</b>]';

		$e .= '<div id="{:id}-trace" class="cake-stack-trace" style="display: none;">';
		$e .= '{:links}{:info}</div>';
		$e .= '</pre>';
		$this->_templates['js']['error'] = $e;

		$t = '<div id="{:id}-trace" class="cake-stack-trace" style="display: none;">';
		$t .= '{:context}{:code}{:trace}</div>';
		$this->_templates['js']['info'] = $t;

		$links = array();
		$link = '<a href="javascript:void(0);" onclick="document.getElementById(\'{:id}-code\')';
		$link .= '.style.display = (document.getElementById(\'{:id}-code\').style.display == ';
		$link .= '\'none\' ? \'\' : \'none\')">Code</a>';
		$links['code'] = $link;

		$link = '<a href="javascript:void(0);" onclick="document.getElementById(\'{:id}-context\')';
		$link .= '.style.display = (document.getElementById(\'{:id}-context\').style.display == ';
		$link .= '\'none\' ? \'\' : \'none\')">Context</a>';
		$links['context'] = $link;

		$this->_templates['js']['links'] = $links;

		$this->_templates['js']['context'] = '<pre id="{:id}-context" class="cake-context" ';
		$this->_templates['js']['context'] .= 'style="display: none;">{:context}</pre>';

		$this->_templates['js']['code'] = '<pre id="{:id}-code" class="cake-code-dump" ';
		$this->_templates['js']['code'] .= 'style="display: none;">{:code}</pre>';

		$e = '<pre class="cake-error"><b>{:error}</b> ({:code}) : {:description} ';
		$e .= '[<b>{:path}</b>, line <b>{:line}]</b></pre>';
		$this->_templates['html']['error'] = $e;

		$this->_templates['html']['context'] = '<pre class="cake-context"><b>Context</b> ';
		$this->_templates['html']['context'] .= '<p>{:context}</p></pre>';
	}

/**
 * Returns a reference to the Debugger singleton object instance.
 *
 * @param string $class Class name.
 * @return object
 */
	public static function getInstance($class = null) {
		static $instance = array();
		if (!empty($class)) {
			if (!$instance || strtolower($class) != strtolower(get_class($instance[0]))) {
				$instance[0] = new $class();
			}
		}
		if (!$instance) {
			$instance[0] = new Debugger();
		}
		return $instance[0];
	}

/**
 * Recursively formats and outputs the contents of the supplied variable.
 *
 * @param mixed $var the variable to dump
 * @param int $depth The depth to output to. Defaults to 3.
 * @return void
 * @see Debugger::exportVar()
 * @link http://book.cakephp.org/2.0/en/development/debugging.html#Debugger::dump
 */
	public static function dump($var, $depth = 3) {
		pr(static::exportVar($var, $depth));
	}

/**
 * Creates an entry in the log file. The log entry will contain a stack trace from where it was called.
 * as well as export the variable using exportVar. By default the log is written to the debug log.
 *
 * @param mixed $var Variable or content to log
 * @param int|string $level type of log to use. Defaults to 'debug'
 * @param int $depth The depth to output to. Defaults to 3.
 * @return void
 * @link http://book.cakephp.org/2.0/en/development/debugging.html#Debugger::log
 */
	public static function log($var, $level = 'debug', $depth = 3) {
		$source = static::trace(array('start' => 1)) . "\n";
		Log::write($level, "\n" . $source . static::exportVar($var, $depth));
	}

/**
 * Overrides PHP's default error handling.
 *
 * @param int $code Code of error
 * @param string $description Error description
 * @param string $file File on which error occurred
 * @param int $line Line that triggered the error
 * @param array $context Context
 * @return bool true if error was handled
 * @deprecated 3.0.0 Will be removed in 3.0. This function is superseded by Debugger::outputError().
 */
	public static function showError($code, $description, $file = null, $line = null, $context = null) {
		$self = Debugger::getInstance();

		if (empty($file)) {
			$file = '[internal]';
		}
		if (empty($line)) {
			$line = '??';
		}

		$info = compact('code', 'description', 'file', 'line');
		if (!in_array($info, $self->errors)) {
			$self->errors[] = $info;
		} else {
			return;
		}

		switch ($code) {
			case E_PARSE:
			case E_ERROR:
			case E_CORE_ERROR:
			case E_COMPILE_ERROR:
			case E_USER_ERROR:
				$error = 'Fatal Error';
				$level = LOG_ERR;
				break;
			case E_WARNING:
			case E_USER_WARNING:
			case E_COMPILE_WARNING:
			case E_RECOVERABLE_ERROR:
				$error = 'Warning';
				$level = LOG_WARNING;
				break;
			case E_NOTICE:
			case E_USER_NOTICE:
				$error = 'Notice';
				$level = LOG_NOTICE;
				break;
			case E_DEPRECATED:
			case E_USER_DEPRECATED:
				$error = 'Deprecated';
				$level = LOG_NOTICE;
				break;
			default:
				return;
		}

		$data = compact(
			'level', 'error', 'code', 'description', 'file', 'path', 'line', 'context'
		);
		echo $self->outputError($data);

		if ($error === 'Fatal Error') {
			exit();
		}
		return true;
	}

/**
 * Outputs a stack trace based on the supplied options.
 *
 * ### Options
 *
 * - `depth` - The number of stack frames to return. Defaults to 999
 * - `format` - The format you want the return. Defaults to the currently selected format. If
 *    format is 'array' or 'points' the return will be an array.
 * - `args` - Should arguments for functions be shown?  If true, the arguments for each method call
 *   will be displayed.
 * - `start` - The stack frame to start generating a trace from. Defaults to 0
 *
 * @param array $options Format for outputting stack trace
 * @return mixed Formatted stack trace
 * @link http://book.cakephp.org/2.0/en/development/debugging.html#Debugger::trace
 */
	public static function trace(array $options = array()) {
		$self = Debugger::getInstance();
		$defaults = array(
			'depth'		=> 999,
			'format'	=> $self->_outputFormat,
			'args'		=> false,
			'start'		=> 0,
			'scope'		=> null,
			'exclude'	=> array('call_user_func_array', 'trigger_error')
		);
		$options = Hash::merge($defaults, $options);

		$backtrace = debug_backtrace();
		$count = count($backtrace);
		$back = array();

		$_trace = array(
			'line' => '??',
			'file' => '[internal]',
			'class' => null,
			'function' => '[main]'
		);

		for ($i = $options['start']; $i < $count && $i < $options['depth']; $i++) {
			$trace = $backtrace[$i] + array('file' => '[internal]', 'line' => '??');
			$signature = $reference = '[main]';

			if (isset($backtrace[$i + 1])) {
				$next = $backtrace[$i + 1] + $_trace;
				$signature = $reference = $next['function'];

				if (!empty($next['class'])) {
					$signature = $next['class'] . '::' . $next['function'];
					$reference = $signature . '(';
					if ($options['args'] && isset($next['args'])) {
						$args = array();
						foreach ($next['args'] as $arg) {
							$args[] = Debugger::exportVar($arg);
						}
						$reference .= implode(', ', $args);
					}
					$reference .= ')';
				}
			}
			if (in_array($signature, $options['exclude'])) {
				continue;
			}
			if ($options['format'] === 'points' && $trace['file'] !== '[internal]') {
				$back[] = array('file' => $trace['file'], 'line' => $trace['line']);
			} elseif ($options['format'] === 'array') {
				$back[] = $trace;
			} else {
				if (isset($self->_templates[$options['format']]['traceLine'])) {
					$tpl = $self->_templates[$options['format']]['traceLine'];
				} else {
					$tpl = $self->_templates['base']['traceLine'];
				}
				$trace['path'] = static::trimPath($trace['file']);
				$trace['reference'] = $reference;
				unset($trace['object'], $trace['args']);
				$back[] = String::insert($tpl, $trace, array('before' => '{:', 'after' => '}'));
			}
		}

		if ($options['format'] === 'array' || $options['format'] === 'points') {
			return $back;
		}
		return implode("\n", $back);
	}

/**
 * Shortens file paths by replacing the application base path with 'APP', and the CakePHP core
 * path with 'CORE'.
 *
 * @param string $path Path to shorten
 * @return string Normalized path
 */
	public static function trimPath($path) {
		if (!defined('CAKE_CORE_INCLUDE_PATH') || !defined('APP')) {
			return $path;
		}

		if (strpos($path, APP) === 0) {
			return str_replace(APP, 'APP/', $path);
		} elseif (strpos($path, CAKE_CORE_INCLUDE_PATH) === 0) {
			return str_replace(CAKE_CORE_INCLUDE_PATH, 'CORE', $path);
		} elseif (strpos($path, ROOT) === 0) {
			return str_replace(ROOT, 'ROOT', $path);
		}

		return $path;
	}

/**
 * Grabs an excerpt from a file and highlights a given line of code.
 *
 * Usage:
 *
 * `Debugger::excerpt('/path/to/file', 100, 4);`
 *
 * The above would return an array of 8 items. The 4th item would be the provided line,
 * and would be wrapped in `<span class="code-highlight"></span>`. All of the lines
 * are processed with highlight_string() as well, so they have basic PHP syntax highlighting
 * applied.
 *
 * @param string $file Absolute path to a PHP file
 * @param int $line Line number to highlight
 * @param int $context Number of lines of context to extract above and below $line
 * @return array Set of lines highlighted
 * @see http://php.net/highlight_string
 * @link http://book.cakephp.org/2.0/en/development/debugging.html#Debugger::excerpt
 */
	public static function excerpt($file, $line, $context = 2) {
		$lines = array();
		if (!file_exists($file)) {
			return array();
		}
		$data = file_get_contents($file);
		if (empty($data)) {
			return $lines;
		}
		if (strpos($data, "\n") !== false) {
			$data = explode("\n", $data);
		}
		if (!isset($data[$line])) {
			return $lines;
		}
		for ($i = $line - ($context + 1); $i < $line + $context; $i++) {
			if (!isset($data[$i])) {
				continue;
			}
			$string = str_replace(array("\r\n", "\n"), "", static::_highlight($data[$i]));
			if ($i == $line) {
				$lines[] = '<span class="code-highlight">' . $string . '</span>';
			} else {
				$lines[] = $string;
			}
		}
		return $lines;
	}

/**
 * Wraps the highlight_string function in case the server API does not
 * implement the function as it is the case of the HipHop interpreter
 *
 * @param string $str the string to convert
 * @return string
 */
	protected static function _highlight($str) {
		if (function_exists('hphp_log') || function_exists('hphp_gettid')) {
			return htmlentities($str);
		}
		$added = false;
		if (strpos($str, '<?php') === false) {
			$added = true;
			$str = "<?php \n" . $str;
		}
		$highlight = highlight_string($str, true);
		if ($added) {
			$highlight = str_replace(
				'&lt;?php&nbsp;<br />',
				'',
				$highlight
			);
		}
		return $highlight;
	}

/**
 * Converts a variable to a string for debug output.
 *
 * *Note:* The following keys will have their contents
 * replaced with `*****`:
 *
 *  - password
 *  - login
 *  - host
 *  - database
 *  - port
 *  - prefix
 *  - schema
 *
 * This is done to protect database credentials, which could be accidentally
 * shown in an error message if CakePHP is deployed in development mode.
 *
 * @param string $var Variable to convert
 * @param int $depth The depth to output to. Defaults to 3.
 * @return string Variable as a formatted string
 * @link http://book.cakephp.org/2.0/en/development/debugging.html#Debugger::exportVar
 */
	public static function exportVar($var, $depth = 3) {
		return static::_export($var, $depth, 0);
	}

/**
 * Protected export function used to keep track of indentation and recursion.
 *
 * @param mixed $var The variable to dump.
 * @param int $depth The remaining depth.
 * @param int $indent The current indentation level.
 * @return string The dumped variable.
 */
	protected static function _export($var, $depth, $indent) {
		switch (static::getType($var)) {
			case 'boolean':
				return ($var) ? 'true' : 'false';
			case 'integer':
				return '(int) ' . $var;
			case 'float':
				return '(float) ' . $var;
			case 'string':
				if (trim($var) === '') {
					return "''";
				}
				return "'" . $var . "'";
			case 'array':
				return static::_array($var, $depth - 1, $indent + 1);
			case 'resource':
				return strtolower(gettype($var));
			case 'null':
				return 'null';
			case 'unknown':
				return 'unknown';
			default:
				return static::_object($var, $depth - 1, $indent + 1);
		}
	}

/**
 * Export an array type object. Filters out keys used in datasource configuration.
 *
 * The following keys are replaced with ***'s
 *
 * - password
 * - login
 * - host
 * - database
 * - port
 * - prefix
 * - schema
 *
 * @param array $var The array to export.
 * @param int $depth The current depth, used for recursion tracking.
 * @param int $indent The current indentation level.
 * @return string Exported array.
 */
	protected static function _array(array $var, $depth, $indent) {
		$out = "[";
		$break = $end = null;
		if (!empty($var)) {
			$break = "\n" . str_repeat("\t", $indent);
			$end = "\n" . str_repeat("\t", $indent - 1);
		}
		$vars = array();

		if ($depth >= 0) {
			foreach ($var as $key => $val) {
				// Sniff for globals as !== explodes in < 5.4
				if ($key === 'GLOBALS' && is_array($val) && isset($val['GLOBALS'])) {
					$val = '[recursion]';
				} elseif ($val !== $var) {
					$val = static::_export($val, $depth, $indent);
				}
				$vars[] = $break . static::exportVar($key) .
					' => ' .
					$val;
			}
		} else {
			$vars[] = $break . '[maximum depth reached]';
		}
		return $out . implode(',', $vars) . $end . ']';
	}

/**
 * Handles object to string conversion.
 *
 * @param string $var Object to convert
 * @param int $depth The current depth, used for tracking recursion.
 * @param int $indent The current indentation level.
 * @return string
 * @see Debugger::exportVar()
 */
	protected static function _object($var, $depth, $indent) {
		$out = '';
		$props = array();

		$className = get_class($var);
		$out .= 'object(' . $className . ') {';
		$break = "\n" . str_repeat("\t", $indent);
		$end = "\n" . str_repeat("\t", $indent - 1);

		if ($depth > 0 && method_exists($var, '__debugInfo')) {
			try {
				return $out . "\n" .
					substr(static::_array($var->__debugInfo(), $depth - 1, $indent), 1, -1) .
					$end . '}';
			} catch (Exception $e) {
				return $out . "\n(unable to export object)\n }";
			}
		}

		if ($depth > 0) {
			$objectVars = get_object_vars($var);
			foreach ($objectVars as $key => $value) {
				$value = static::_export($value, $depth - 1, $indent);
				$props[] = "$key => " . $value;
			}

			$ref = new \ReflectionObject($var);

			$filters = array(
				\ReflectionProperty::IS_PROTECTED => 'protected',
				\ReflectionProperty::IS_PRIVATE => 'private',
			);
			foreach ($filters as $filter => $visibility) {
				$reflectionProperties = $ref->getProperties($filter);
				foreach ($reflectionProperties as $reflectionProperty) {
					$reflectionProperty->setAccessible(true);
					$property = $reflectionProperty->getValue($var);

					$value = static::_export($property, $depth - 1, $indent);
					$key = $reflectionProperty->name;
					$props[] = sprintf('[%s] %s => %s', $visibility, $key, $value);
				}
			}

			$out .= $break . implode($break, $props) . $end;
		}
		$out .= '}';
		return $out;
	}

/**
 * Get/Set the output format for Debugger error rendering.
 *
 * @param string $format The format you want errors to be output as.
 *   Leave null to get the current format.
 * @return mixed Returns null when setting. Returns the current format when getting.
 * @throws \InvalidArgumentException when choosing a format that doesn't exist.
 */
	public static function outputAs($format = null) {
		$self = Debugger::getInstance();
		if ($format === null) {
			return $self->_outputFormat;
		}

		if ($format !== false && !isset($self->_templates[$format])) {
			throw new InvalidArgumentException('Invalid Debugger output format.');
		}
		$self->_outputFormat = $format;
	}

/**
 * Add an output format or update a format in Debugger.
 *
 * `Debugger::addFormat('custom', $data);`
 *
 * Where $data is an array of strings that use String::insert() variable
 * replacement. The template vars should be in a `{:id}` style.
 * An error formatter can have the following keys:
 *
 * - 'error' - Used for the container for the error message. Gets the following template
 *   variables: `id`, `error`, `code`, `description`, `path`, `line`, `links`, `info`
 * - 'info' - A combination of `code`, `context` and `trace`. Will be set with
 *   the contents of the other template keys.
 * - 'trace' - The container for a stack trace. Gets the following template
 *   variables: `trace`
 * - 'context' - The container element for the context variables.
 *   Gets the following templates: `id`, `context`
 * - 'links' - An array of HTML links that are used for creating links to other resources.
 *   Typically this is used to create javascript links to open other sections.
 *   Link keys, are: `code`, `context`, `help`. See the js output format for an
 *   example.
 * - 'traceLine' - Used for creating lines in the stacktrace. Gets the following
 *   template variables: `reference`, `path`, `line`
 *
 * Alternatively if you want to use a custom callback to do all the formatting, you can use
 * the callback key, and provide a callable:
 *
 * `Debugger::addFormat('custom', array('callback' => array($foo, 'outputError'));`
 *
 * The callback can expect two parameters. The first is an array of all
 * the error data. The second contains the formatted strings generated using
 * the other template strings. Keys like `info`, `links`, `code`, `context` and `trace`
 * will be present depending on the other templates in the format type.
 *
 * @param string $format Format to use, including 'js' for JavaScript-enhanced HTML, 'html' for
 *    straight HTML output, or 'txt' for unformatted text.
 * @param array $strings Template strings, or a callback to be used for the output format.
 * @return array The resulting format string set.
 */
	public static function addFormat($format, array $strings) {
		$self = Debugger::getInstance();
		if (isset($self->_templates[$format])) {
			if (isset($strings['links'])) {
				$self->_templates[$format]['links'] = array_merge(
					$self->_templates[$format]['links'],
					$strings['links']
				);
				unset($strings['links']);
			}
			$self->_templates[$format] = $strings + $self->_templates[$format];
		} else {
			$self->_templates[$format] = $strings;
		}
		return $self->_templates[$format];
	}

/**
 * Switches output format, updates format strings.
 * Can be used to switch the active output format:
 *
 * @param string $format Format to use, including 'js' for JavaScript-enhanced HTML, 'html' for
 *    straight HTML output, or 'txt' for unformatted text.
 * @param array $strings Template strings to be used for the output format.
 * @return string
 * @deprecated 3.0.0 Use Debugger::outputAs() and Debugger::addFormat(). Will be removed
 *   in 3.0
 */
	public static function output($format = null, $strings = array()) {
		$self = Debugger::getInstance();
		$data = null;

		if ($format === null) {
			return Debugger::outputAs();
		}

		if (!empty($strings)) {
			return Debugger::addFormat($format, $strings);
		}

		if ($format === true && !empty($self->_data)) {
			$data = $self->_data;
			$self->_data = array();
			$format = false;
		}
		Debugger::outputAs($format);
		return $data;
	}

/**
 * Takes a processed array of data from an error and displays it in the chosen format.
 *
 * @param string $data Data to output.
 * @return void
 */
	public function outputError($data) {
		$defaults = array(
			'level' => 0,
			'error' => 0,
			'code' => 0,
			'description' => '',
			'file' => '',
			'line' => 0,
			'context' => array(),
			'start' => 2,
		);
		$data += $defaults;

		$files = $this->trace(array('start' => $data['start'], 'format' => 'points'));
		$code = '';
		$file = null;
		if (isset($files[0]['file'])) {
			$file = $files[0];
		} elseif (isset($files[1]['file'])) {
			$file = $files[1];
		}
		if ($file) {
			$code = $this->excerpt($file['file'], $file['line'] - 1, 1);
		}
		$trace = $this->trace(array('start' => $data['start'], 'depth' => '20'));
		$insertOpts = array('before' => '{:', 'after' => '}');
		$context = array();
		$links = array();
		$info = '';

		foreach ((array)$data['context'] as $var => $value) {
			$context[] = "\${$var} = " . $this->exportVar($value, 3);
		}

		switch ($this->_outputFormat) {
			case false:
				$this->_data[] = compact('context', 'trace') + $data;
				return;
			case 'log':
				$this->log(compact('context', 'trace') + $data);
				return;
		}

		$data['trace'] = $trace;
		$data['id'] = 'cakeErr' . uniqid();
		$tpl = $this->_templates[$this->_outputFormat] + $this->_templates['base'];

		if (isset($tpl['links'])) {
			foreach ($tpl['links'] as $key => $val) {
				$links[$key] = String::insert($val, $data, $insertOpts);
			}
		}

		if (!empty($tpl['escapeContext'])) {
			$context = h($context);
		}

		$infoData = compact('code', 'context', 'trace');
		foreach ($infoData as $key => $value) {
			if (empty($value) || !isset($tpl[$key])) {
				continue;
			}
			if (is_array($value)) {
				$value = implode("\n", $value);
			}
			$info .= String::insert($tpl[$key], array($key => $value) + $data, $insertOpts);
		}
		$links = implode(' ', $links);

		if (isset($tpl['callback']) && is_callable($tpl['callback'])) {
			return call_user_func($tpl['callback'], $data, compact('links', 'info'));
		}
		echo String::insert($tpl['error'], compact('links', 'info') + $data, $insertOpts);
	}

/**
 * Get the type of the given variable. Will return the class name
 * for objects.
 *
 * @param mixed $var The variable to get the type of
 * @return string The type of variable.
 */
	public static function getType($var) {
		if (is_object($var)) {
			return get_class($var);
		}
		if ($var === null) {
			return 'null';
		}
		if (is_string($var)) {
			return 'string';
		}
		if (is_array($var)) {
			return 'array';
		}
		if (is_int($var)) {
			return 'integer';
		}
		if (is_bool($var)) {
			return 'boolean';
		}
		if (is_float($var)) {
			return 'float';
		}
		if (is_resource($var)) {
			return 'resource';
		}
		return 'unknown';
	}

/**
 * Verifies that the application's salt and cipher seed value has been changed from the default value.
 *
 * @return void
 */
	public static function checkSecurityKeys() {
		if (Security::salt() === '__SALT__') {
			trigger_error(sprintf('Please change the value of %s in %s to a salt value specific to your application.', '\'Security.salt\'', 'ROOT/config/app.php'), E_USER_NOTICE);
		}
	}

}