/CakePHP 3.8

Class ErrorHandler

Error Handler provides basic error and exception handling for your application. It captures and handles all unhandled exceptions and errors. Displays helpful framework errors when debug > 1.

Uncaught exceptions

When debug < 1 a CakeException will render 404 or 500 errors. If an uncaught exception is thrown and it is a type that ErrorHandler does not know about it will be treated as a 500 error.

Implementing application specific exception handling

You can implement application specific exception handling in one of a few ways. Each approach gives you different amounts of control over the exception handling process.

  • Modify config/error.php and setup custom exception handling.
  • Use the exceptionRenderer option to inject an Exception renderer. This will let you keep the existing handling logic but override the rendering logic.

Create your own Exception handler

This gives you full control over the exception handling process. The class you choose should be loaded in your config/error.php and registered as the default exception handler.

Using a custom renderer with exceptionRenderer

If you don't want to take control of the exception handling, but want to change how exceptions are rendered you can use exceptionRenderer option to choose a class to render exception pages. By default Cake\Error\ExceptionRenderer is used. Your custom exception renderer class should be placed in src/Error.

Your custom renderer should expect an exception in its constructor, and implement a render method. Failing to do so will cause additional errors.

Logging exceptions

Using the built-in exception handling, you can log all the exceptions that are dealt with by ErrorHandler by setting log option to true in your config/error.php. Enabling this will log every exception to Log and the configured loggers.

PHP errors

Error handler also provides the built in features for handling php errors (trigger_error). While in debug mode, errors will be output to the screen using debugger. While in production mode, errors will be logged to Log. You can control which errors are logged by setting errorLevel option in config/error.php.

Logging errors

When ErrorHandler is used for handling errors, you can enable error logging by setting the log option to true. This will log all errors to the configured log handlers.

Controlling what errors are logged/displayed

You can control which errors are logged / displayed by ErrorHandler by setting errorLevel. Setting this to one or a combination of a few of the E_* constants will only enable the specified errors:

$options['errorLevel'] = E_ALL & ~E_NOTICE;

Would enable handling for all non Notice errors.

Extended by Cake\Error\ErrorHandler
Namespace: Cake\Error
See: \Cake\Error\ExceptionRenderer for more information on how to customize exception rendering.
Location: Error/ErrorHandler.php

Inherited Properties

Method Summary

Method Detail

__construct()source public

__construct( array $options = [] )



array $options optional []
The options for error handling.

_clearOutput()source protected

_clearOutput( )

Clear output buffers so error pages display properly.

Easily stubbed in testing.

_displayError()source protected

_displayError( array $error , boolean $debug )

Display an error.

Template method of BaseErrorHandler.


array $error
An array of error data.
boolean $debug
Whether or not the app is in debug mode.

_displayException()source protected

_displayException( Exception $exception )

Displays an exception response body.


Exception $exception
The exception to display.


When the chosen exception renderer is invalid.

_logInternalError()source protected

_logInternalError( Throwable|Exception $exception )

Logs both PHP5 and PHP7 errors.

The PHP5 part will be removed with 4.0.


Throwable|Exception $exception

_sendResponse()source protected

_sendResponse( string|Cake\Http\Response $response )

Method that can be easily stubbed in testing.


string|Cake\Http\Response $response
Either the message or response object.

Methods inherited from Cake\Error\BaseErrorHandler

_getMessage()source protected

_getMessage( Exception $exception )

Generates a formatted error message


Exception $exception
Exception instance


Formatted message

_logError()source protected

_logError( string $level , array $data )

Log an error.


string $level
The level name of the log.
array $data
Array of error data.



_logException()source protected

_logException( Exception $exception )

Handles exception logging


Exception $exception
Exception instance.



_requestContext()source protected

_requestContext( Cake\Http\ServerRequest $request )

Get the request context for an error/exception trace.


Cake\Http\ServerRequest $request
The request to read from.



_stop()source protected

_stop( integer $code )

Stop the process.

Implemented in subclasses that need it.


integer $code
Exit code.

getMessageForException()source protected

getMessageForException( Exception $exception , boolean $isPrevious = false )

Generate the message for the exception


Exception $exception
The exception to log a message for.
boolean $isPrevious optional false
False for original exception, true for previous


Error message

handleError()source public

handleError( integer $code , string $description , string|null $file = null , integer|null $line = null , array|null $context = null )

Set as the default error handler by CakePHP.

Use config/error.php to customize or replace this error handler. This function will use Debugger to display errors when debug > 0. And will log errors to Log, when debug == 0.

You can use the 'errorLevel' option to set what type of errors will be handled. Stack traces for errors can be enabled with the 'trace' option.


integer $code
Code of error
string $description
Error description
string|null $file optional null
File on which error occurred
integer|null $line optional null
Line that triggered the error
array|null $context optional null


True if error was handled

handleException()source public

handleException( Exception $exception )

Handle uncaught exceptions.

Uses a template method provided by subclasses to display errors in an environment appropriate way.


Exception $exception
Exception instance.


When renderer class not found



handleFatalError()source public

handleFatalError( integer $code , string $description , string $file , integer $line )

Display/Log a fatal error.


integer $code
Code of error
string $description
Error description
string $file
File on which error occurred
integer $line
Line that triggered the error



increaseMemoryLimit()source public

increaseMemoryLimit( integer $additionalKb )

Increases the PHP "memory_limit" ini setting by the specified amount in kilobytes


integer $additionalKb
Number in kilobytes

mapErrorCode()source public static

mapErrorCode( integer $code )

Map an error code into an Error word, and log location.


integer $code
Error code to map


Array of error word, and log location.

register()source public

register( )

Register the error and exception handlers.

wrapAndHandleException()source public

wrapAndHandleException( Exception|Error $exception )

Checks the passed exception type. If it is an instance of Error then, it wraps the passed object inside another Exception object for backwards compatibility purposes.


Exception|Error $exception
The exception to handle

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