Making some Objects in PHP

gistfile1.php

<?php


/*
 * Send all required arguments.
 */
$test = new My_Object( array(
	'one'   => 1,
	'two'   => 2,
	'three' => 3,
	) );

print '<pre>'; 
gettype( $test );  // Should be "My_Object"
var_dump( empty( $test ) ); // false as expected.
var_dump( $test );
print '</pre>';



/*
 * This object is missing one required argument.
 */
$test = new My_Object( array(
	'one'   => 1,
	'two'   => 2,
	) );


print '<pre>';
gettype( $test ); // Would be neat if this could return some sort of error object.
var_dump( empty( $test ) ); // Even though all properties have been removed, this still returns false?
var_dump( $test );
print '</pre>';


class My_Object {

	public $one   = null;
	public $two   = null;
	public $three = null;
	
	public function __construct( $args = array() ) {

		$diff = array_diff_key( get_object_vars( $this ), $args );

		if ( ! empty( $diff ) ) {
			
			/* Let them know they're doing it wrong. */
			trigger_error( 'Could not construct object.' );
			
			/* It's possible to kill all of the properties. */
			foreach( array_keys( get_object_vars( $this ) ) as $property ) {
				unset( $this->$property );
			}
			
			/* Anyway to change type of object before return? */
			return;
		}

		$this->one   = (int) $args['one'];
		$this->two   = (int) $args['two'];
		$this->three = (int) $args['three'];
	}
}

I meant "others using the code" as in anyone who forks your project or uses it as a base/inspiration for their own system.

Now that I know what you're trying to do (rather than mucking around with My_Objects and $tests), have you considered using a factory method?

Basically:

$test = create_my_object( $args );

function create_my_object( $args = array() ) {
    if ( Icon_Set::check_args( $args ) ) {
        return new Icon_Set( $args );
    } else {
        return new My_Error( "You're doing it wrong!" );
    }
}

Then $test will either be an instance of Icon_Set or some custom error object if it was configured improperly.

(OK, it's not a real factory method ... but similar enough ...)