Question

I’m having some problems getting my object to gracefully fail out if an invalid parameter is given during instantiation. I have a feeling it’s a small syntax thing somewhere that I simply need fresh eyes on. Any help is more than appreciated.

class bib {    protected $bibid;    public function __construct($new_bibid) {       if(!$this->bibid = $this->validate_bibid($new_bibid)) {         echo 'me';         return false;       }       //carry on with other stuff if valid bibid     }      private static function validate_bibid($test_bibid) {        //call this method every time you get a bibid from the user        if(!is_int($test_bibid)) {             return false;        }        return (int)$test_bibid;     }  } 

Note that I have an ‘echo me’ line in there to demonstrate that it is in fact, returning false. The way that I’m calling this in my PHP is as follows:

if(!$bib=new bib('612e436')) {     echo 'Error Message'; } else {     //do what I intend to do with the object } 

This outputs the me from above, but then continues on into the else block, doing what I intend to do with a valid object.

Can anyone spot anything I’m doing wrong in there?

Thanks!

Answer 1

You can’t return in a constructor in PHP – the object is still created as normal.

You could use a factory or something similar;

if(!$bib = Bib_Factory::loadValidBib('612e436')){     echo 'Error Message'; } else {     //do what I intend to do with the object } 

Or throw an exception in the constructor and use a try catch instead of the if statement.