php exceptions extra parameters

Question

Is it possible to add an extra parameter when trowing an exception?

When i trow an exception I send along the error message but i would also like to send along the name of the field in a extra parameter. Something like

throw new Exception('this is an error message', 'the field');

So when i display the message i can do something like this

show_error($e->getFieldname, $e->getMessage());

Answer 1

No, you would have to subclass Exception with your own implementation and add that method.

class FieldException extends Exception
{
    protected $_field;
    public function __construct($message="", $code=0 , Exception $previous=NULL, $field = NULL)
    {
        $this->_field = $field;
        parent::__construct($message, $code, $previous);
    }
    public function getField()
    {
        return $this->_field;
    }
}

But actually, I am not a friend of adding methods or properties to Exceptions. An Exception represents just that: something exceptional that happened in your application. The "field" property is really not part of the Exception, but part of the exception message, so I'd probably use a proper message like:

Wrong value for field foo. Excepted string, got integer

Answer 2

You can implement your own Exception class, and customize it.

See Extending Exceptions article for details.