Re: OOP design question

"Mike Smith" <msmith@larrymethvin.com> wrote in message news:20040105160140.76626.qmail@pb1.pair.com... > I am starting to get a handle (I think) on OOP. I was wondering if > anyone would care to comment on what I think I understand: > > For simplicity's sake class.php contains AddItem() and DisplayItems(). > Since submitting form data > > <?php > include('class.php'); > > If(!$_POST['submit']){ //Do I need to instantiate(?) $po everytime the > page reloads? > $po = new PO; > } If you instantiate on every page load, you will only have one item - the last one added. So, you will need to instantiate only once, and then store the object in a session variable - but beware! Assigning the local variable to the object will make a copy of the object stored in the session, so you will have to either 1). Set the session variable back to $po at the end of the page, as such: $_SESSION[po] = $po; or 2). Set the local variable via reference to the session variable when initializing $po at the beginning of the page (which references the existing object, and does NOT make a copy), as such: $po = &$_SESSION[po]; // notice the & which sets $po by reference, rather than making a copy. > > > If($_POST['submit']){ > $po->AddItem(); > } > > <form action="$PHP_SELF" method="POST" > > ...form fields and a submit button... > </form> > > $po->DisplayItems(); > > ?> > > Is this a good basic methodology (aside from checking the form fields > for valid characters). > > Thanks, > Mike Smith