I have written a few sites (shopping carts, product databases, imap mail reader, domain name checker) using objects but I feel like I need more than the odd chapter about OOP in the various PHP books I have to take me further. I have come from a web design background so don't have experience in OOP languages like Java.
So can you recommend me a good book. I'm looking for the ideas and structures behind good OOP more than useable PHP examples - I want something that will let me see what makes OOP really good.
Any suggestions are appreciated.
Fergus