Class of classes

[timgolding]

I am producing a shopping cart system for a friends gallery web site. I have produced a class for products so when the user adds a product it will create a new class from the data about that product. That class then needs to be set as session data. How do I allow multiple classes to added to an order?
Do I need a order class? Is there such thing as a class of classes (oder class of product classes)? Or do I need an array of product classes.

So here is the class so far:

<?PHP

Class item_class{
// a class to add the items to session
    var $cat;  //category of picture
    var $subcat;  // sub category of picture
    var $product;  //product identifier
    var $title;  //title of artwork
    var $pic_cat;  //legend for category and sub cat
    var $frame;  // the frame style 
    var $dims;  //dimesions of product
    var $price;  //price fo product
    var $img_link;  //link to the gallery image
    var $txt_link;  //link to the gallery description text file


    function add_to_order(){
    //add whole product to the order

    }

    function add_frame(){
    // add the picture frame part to a customisable commision order

    }

    function add_picture(){
    // add the picture part to a customisable commision order

    }
}
?>

Any advice would be greatly apprecited here.

Thanks

[rafiki]

i could set up an online shop for your friend, pm me an offer!

[Beagle]

I'm not sure what the exact needs are, but you maybe under-utilizing object-oriented programming.

If all of your products will have the same properties, like size, weight, color, etc, then you create a class that has all of those properties. When someone adds a new product, you create an instance of the product class. This is an object. You then assign to the object all the properties of the new product.

There's no need for extra classes unless you plan on creating new products with completely new properties that don't fit into a mold. Even then, if they are few and far between, you could provide an associative array that stores all the extra properties and their values, and still only need on product class.

I hope this helps you somewhat, like I said, I have no idea what your OO experience is like. If you have more questions, just ask.

[timgolding]

I think i get it

Thanks, So something like this

<?PHP

Class item_class{
// a class to add the items to session
    var $cat;
    var $subcat;
    var $product;
    var $title;
    var $pic_cat;
    var $frame;
    var $dims;
    var $price;
    var $img_link;
    var $txt_link;
    var $add;


    function add_to_order(){
    //add whole product to the order
        $this->add="whole";
        $_SESSION[$this->product]=$this->item_class;
    }

    function add_frame(){
    // add the picture frame part to a customisable commision order
        $this->add="frame";
        $_SESSION[$this->product]=$this->item_class;
    }

    function add_picture(){
    // add the picture part to a customisable commision order
        $this->add="picture";
        $_SESSION[$this->product]=$this->item_class;
    }
}
?>

The idea here is to add the whole class object to the session data where the identifier to that session object is the classes product. Is this what you mean. Or do I have to make a seperate associative array and assing that to a $_SESSION["cart"] or soemthing?

[Beagle]

It would be more like:

#....your class definition here...
$newProduct = new Product();
$newProduct->title = 'New Title';
$_SESSION['myNewProduct'] = $newProduct;

Now, if you want to carry multiple products in the session, then you'll have to store with different keys or you'll have to store an array with your objects in it.

Does that answer your question?

[timgolding]

So I need to get rid of my class functions and add the new class to the session outside of the class. So something like this?

<?PHP

Class item_class{
// item class declaration
    var $cat;
    var $subcat;
    var $product;
    var $title;
    var $pic_cat;
    var $frame;
    var $dims;
    var $price;
    var $img_link;
    var $txt_link;
    var $add;
}

//create new class
$item=new item_class();

// GET the form data and store in new class
$item->cat=$_GET['cat'];
$item->subcat=$_GET['subcat'];
$item->product=$_GET['product'];
$item->title=$_POST['title'];
$item->pic_cat=$_POST['cat'];
$item->frame=$_POST['frame'];
$item->dims=$_POST['dims'];
$item->price=$_POST['price'];
$item->img_link=$_POST['img_link'];
$item->txt_link=$_POST['txt_link'];
$item->add=$_GET['add'];

//store class in session variable
$_SESSSION[$item->product] = $item;

I think this is working it seems to be storing something, problem is I have no idea how to retirve it again when they are ready to checkout. Any ideas?
Thanks again....

[timgolding]

Hi again here is the output of the SESSION data when i just added a few instances to the SESSION and echoed $_SESSION.


Array ( [pinman_1.txt] => __PHP_Incomplete_Class Object ( [__PHP_Incomplete_Class_Name] => item_class [cat] => pinmen [subcat] => sports [product] => pinman_1.txt [title] => Runner [pic_cat] => PMPS [frame] => Paper Maché News Paper [dims] => W 30cm x H 40cm [price] => £40 [img_link] => ./Gallerys/listed/pinmen/sports/pinman_1.jpg [txt_link] => ./Gallerys/listed/pinmen/sports/pinman_1.txt [add] => frame ) [pinman_11.txt] => __PHP_Incomplete_Class Object ( [__PHP_Incomplete_Class_Name] => item_class [cat] => pinmen [subcat] => sports [product] => pinman_11.txt [title] => Runner [pic_cat] => PMPS [frame] => Paper Maché News Paper [dims] => W 30cm x H 40cm [price] => £40 [img_link] => ./Gallerys/listed/pinmen/sports/pinman_11.jpg [txt_link] => ./Gallerys/listed/pinmen/sports/pinman_11.txt [add] => whole ) )

What does " __PHP_Incomplete_Class Object ( [__PHP_Incomplete_Class_Name]" mean. Im scared

[rafiki]

dude, just get your friend to pay me to do it, will be much quicker

[timgolding]

dude, just get your friend to pay me to do it, will be much quicker

NO..............

[rafiki]

ok ifne, then may i recommend zencart

[GJay]

The incomplete class name is due to you not having included the class definition before the session gets initialised- PHP sees the object and it's properties, but it doesn't know what it should do with it.
to fix the problem, include the file that contains the code for the class before you call session_start();

[timgolding]

Thank you Beagle and GJay you have both been extremely useful. This was my fisrt attempt at OO programming in PHP and it was a great learing experience. I'm pretty sure I have everything I need to finish my scripts now Thanks again