If you use the ErrorException exception to have a unified error management, I'll advise you to test against error_reporting in the error handler, not in the exception handler as you might encounter some headaches like blank pages as error_reporting might not be transmitted to exception handler.

So instead of :

<?php

function exception_error_handler($errno, $errstr, $errfile, $errline )
{
    throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
}

set_error_handler("exception_error_handler");

function catchException($e)
{
    if (error_reporting() === 0)
    {
        return;
    }

    // Do some stuff
}

set_exception_handler('catchException');

?>

It would be better to do :

<?php

function exception_error_handler($errno, $errstr, $errfile, $errline )
{
    if (error_reporting() === 0)
    {
        return;
    }

    throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
}

set_error_handler("exception_error_handler");

function catchException($e)
{
    // Do some stuff
}

set_exception_handler('catchException');

?>