PHP - is it possible to use custom exception handler (set_exception_handler) inside a __destruct() method?

Question

Is there way to use a custom exception handler, instead of the default exception handler, inside a class's __destruct method?

For example:

function myExceptionHandler($e)
{
    echo "custom exception handler";
    if(is_object($e) && method_exists($e,'getMessage'))
        echo $e->getMessage();
}
set_exception_handler('myExceptionHandler');
class MyClass {
    public function __construct()
    {
        // myExceptionHandler handles this exception
        //throw new Exception("Exception from " . __METHOD__);
    }

    public function doStuff()
    {
        // myExceptionHandler handles this exception
        //throw new Exception("Exception from " . __METHOD__);
    }

    public function __destruct()
    {
        // default exception handler 
        throw new Exception("Exception from " . __METHOD__);
    }

}

$myclass = new MyClass();
$myclass->doStuff();

Even if set_exception_handler is called within the __destruct method, the default handler is still used:

    public function __destruct()
    {
        $callable = function($e)
        {
            echo "custom exception handler".PHP_EOL;
            if(is_object($e) && method_exists($e,'getMessage'))
                echo $e->getMessage();
        };
        set_exception_handler($callable);
        throw new Exception("Exception from " . __METHOD__); // default exception handler
    }

Community · Accepted Answer · 2020-06-20 09:12:55Z

1

From the manual page

Note:

Attempting to throw an exception from a destructor (called in the time of script termination) causes a fatal error.

So using exceptions in a destructor is probably a bad idea in the first place. There may not be any of your code around when the script has finished to process the exception that is thrown.

Perhaps this code would be better placed in a close() method of the class instead.

edited Jun 20, 2020 at 9:12

CommunityBot

11 silver badge

answered Jan 22, 2020 at 16:37

Nigel Ren

57.3k11 gold badges49 silver badges59 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

billrichards Over a year ago

thanks, yes I ended up doing something similar to a close() method

Millard · Accepted Answer · 2020-01-22 16:36:32Z

1

Maybe something like this?

<?php

class MyException extends Exception {
    public function __construct() {
        parent::__construct('my exception');
    }
}

class MyClass {
    public function __construct()
    {
        // myExceptionHandler handles this exception
        //throw new Exception("Exception from " . __METHOD__);
    }

    public function doStuff()
    {
        // myExceptionHandler handles this exception
        //throw new Exception("Exception from " . __METHOD__);
    }

    public function __destruct()
    {
        // default exception handler 
        throw new MyException();
    }

}

$myclass = new MyClass();
$myclass->doStuff();

answered Jan 22, 2020 at 16:36

Millard

1,1671 gold badge9 silver badges20 bronze badges

1 Comment

billrichards Over a year ago

I don't think this works either (tried something similar). Per Nigel and the manual, it's not possible (and perhaps not desirable)

Collectives™ on Stack Overflow

PHP - is it possible to use custom exception handler (set_exception_handler) inside a __destruct() method?

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related