Create custom exception handler

Exception handling is used to change the normal flow of the code execution if a specified error (exceptional) condition occurs. This condition is called an exception.

PHP has an exception model similar to that of other programming languages. Exceptions are important and provides a better control over error handling.

There are following functions which can be used from Exception class.

• getMessage()- message of exception
• getCode() - code of exception
• getFile() - source filename
• getLine() - source line
• getTrace() - n array of the backtrace()
• getTraceAsString() - formated string of trace

<?php

try {

    $error = 'Always throw this error';

    throw new Exception($error);

    // Code following an exception is not executed.

    echo 'Never executed';

} catch (Exception $e) {

    echo 'Caught exception: ',  $e->getMessage(), "\n";

}

// Continue execution

echo 'Hello World';

?>

In the above example $e->getMessage function is uded to get error 

message. 

All errors and warnings should be logged. Based on the severity of an error, notifications should be sent out to other systems/teams. So that you can better gauge its severity, PHP provides several built-in error levels to describe the nature of an error. Each level is represented by an integer value and named constant which can be used by the programmer.  

The following table is generated from http://php.net/manual/en/errorfunc.constants.php

You can extend PHP's built in Exception class and create custom Exception handler for more flexibility.

Here I have created a custom exception handler

<?php

error_reporting(E_ALL);
// error_reporting(E_ALL | E_STRICT);  // From PHP 5.4.0 E_STRICT is a part of E_ALL

class NoticeException extends Exception { 

    public function __toString() {

        return  "NOTICE :: $this->message";

    }

}

class WarningException extends Exception { 

    public function __toString() {

        return  "WARNING :: $this->message";

    }

}

class StrictException extends Exception {

    public function __toString() {

        return  "STRICT :: $this->message";

    }

}

class UserThrownException extends Exception {

    public function __toString() {

        return "USER ERROR :: $this->message";

    }

}

class UserDepricatedException extends Exception {

    public function __toString() {

        return "USER DEPRICATED ERROR :: $this->message";

    }

}

class OtherErrorException extends Exception {

    public function __toString() {

        return  "OTHER ERROR :: $this->message";

    }

}

function pc_error_handler($errno,$error,$file,$line,$context) {

    $message = "[$error][FILE : $file][LINE : $line]";

    

    if($errno == E_WARNING) {

        throw new WarningException($message);

    } else if($errno == E_NOTICE) {

        throw new NoticeException($message);

    } else if($errno == E_STRICT) {

        throw new StrictException($message);

    } else if($errno == E_USER_ERROR) {

        throw new UserThrownException($message);

    } else if($errno == E_USER_DEPRECATED) {

        throw new UserDepricatedException($message);

    } else {

        throw new OtherErrorException($message);

    }

}