objects question

[turbo99]

I am working on creating a shopping cart. This is a good learning experience (I am a novice) for me regarding oop but I have ran into a road block, "brain fart" or just plain stymied and need some help.

I have a Cart and Cart_Item class. I create a Cart object using a Cart_Item object. I am now working on the code to display the cart contents. I am confused on how to call the attributes of the Cart_Item object inside the Cart object. (If I am not saying this right please correct me.)

I know about accessor or mutator methods but how do I write them to get an attribute of the Cart_Item out of the Cart object?

Here are parts of both classes.

class Cart_Item
{
var $inumber;
var $name;
var $quant;
var $price;
var $descr;
var $gtotprice;

    function Cart_Item(&$inumber,&$name,&$quant,&$price,&$descr)
    {
        $this->_init();

        $this->inumber = $inumber;
        $this->name    = $name;
        $this->quant   = sprintf("%d", $quant);
        $this->price   = sprintf("%0.4f", $price);
		$this->descr   = $descr;

        $this->_calc();
    }

class CART
{
var $items;
var $gtotprice;

    function CART()
    {
        $this->_init();
    }

    function add($inumber,$name,$quant,$price,$descr)
    {
        if(!is_object($this->items[$inumber]))
        {
             $this->items[$inumber] = new Cart_Item($inumber,$name,$quant,$price,$descr);
             $this->_refresh();
        }
    }

Your help would be greatly appreciated.

Thanks in advance,

Alex 😕

[toolaphile69]

Hello, are you calling from a seperate file??? The best way to do it is to seperate your items.... like your class files seperated from the file that will actually call the info you desire.... example would be...

build you class file such as shopping_cart.php then have an include file named include.php <------- inside here you would put in the file/class you want included so you can load it from any file by using the include statement.....yada yada.

then in your file where you want this info output you would put in the we will call it shop_cart.php

this is where you would put your
<?
$products = $cart->get_products();

etc.... since you have the include file pointing at your class file you can call what you need from there..... you may also want to build another include file that has table params etc so the output is formatted......etc...hope this helps you out if you need a bit more help let me know....

"Think for yourself question authority"

[turbo99]

thank you for your response. I do have an include statement for my class code on e.g my cart_view.php page.

An attribute for my Cart object is $items which are Cart_Item objects. I need for example the $cart_item->productid and I dont know how to get to that attribute since it is part of the Cart_Item class. (There is no inheritance between the two classes. )

I know to use this to call methods and attributes of the cart class.

$cart->items

But how do I get to the those attributes

I maybe chasing my tail on this and confusing myself.

Alex

[the_Igel]

As I understand your question, you need to put it this way:

$id = $cart->items[0]->product_id;

[turbo99]

thank you the_Igel for your response. Did I create an index array? I am a novice so pardon my ignorance.

this is what I used to create the Cart object with a property called items

$this->items[$inumber] = new Cart_Item($inumber,$name,$quant,$price,$descr);

so the items inside the Cart_Item object can be retrieved using your suggestion? I will try it out.

thx
Alex

[the_Igel]

$this->items[$inumber] = new Cart_Item($inumber,$name,$quant,$price,$descr);

• That is: $this->items is an array, and you add an item to this array. That item has index $inumber and equals to Cart_Item object.

It isn't clear to me, what is $inumber for, though. If it doesn't contain any useful information, you can omit it:

$this->items[] = new Cart_Item(......);
In this case the first unused index will be assigned to the item.

Generally, when one defines an array, one writes:
$a[] = 1;
$a[] = 'foobar';
$a[] = f($x) + g($x);

It results in array $a:
0 => 1
1 => 'foobar'
2 => f($x) + g($x) //whatever it equals to.

[turbo99]

Hello the_Igel

Here is the code I am using to create a shopping cart. Maybe this could help explain what the code is doing because if I tried I would only confuse you like I already am.

<?php

if(!isset($Cart_Included) || !$Cart_Included)
{
$_Cart_Included = 1;

class sCartItem
{
    var $inumber;
    var $name;
    var $quant;
    var $price;
    var $descr;
	var $gtotprice;

    function sCartItem(&$inumber,&$name,&$quant,&$price,&$descr)
    {
        $this->_init();

        $this->inumber = $inumber;
        $this->name    = $name;
        $this->quant   = sprintf("%d", $quant);
        $this->price   = sprintf("%0.4f", $price);
		$this->descr   = $descr;

        $this->_calc();
    }

    function update(&$quant)
    {
        $this->quant = $quant;
        $this->_calc();
    }

    function get_gtotprice()
    {
        return $this->gtotprice;
    }

	function get_product_name()
    {
		return $this->name;

    }

    function get_all()
    {
        $values = array();
        $values["cart.inumber"]   = $this->inumber;
        $values["cart.name"]      = $this->name;
        $values["cart.quant"]     = sprintf("%d", $this->quant);
        $values["cart.price"]     = sprintf("%0.2f", $this->price);
        $values["cart.gtotprice"] = sprintf("%0.2f", $this->gtotprice);
        $values["cart.descr"]	  = $this->descr;

        return $values;
    }

    function _init()
    {
        $this->inumber   = null;
        $this->name      = "";
        $this->quant     = 0;
        $this->price     = 0.00;
        $this->descr     = "";
        $this->gtotprice = 0.00;
	}

    function _calc()
    {
        //$this->ntotprice = sprintf("%0.4f", $this->nprice * $this->quant);
        $this->gtotprice = sprintf("%0.4f", $this->price * $this->quant);
    }
}

class CART
{
    var $items;
    var $gtotprice;

    function CART()
    {
        $this->_init();
    }

    function add($inumber,$name,$quant,$price,$descr)
    {
        if (isset($inumber)) {
             $this->items[$inumber] = new sCartItem($inumber,$name,$quant,$price,$descr);
             $this->_refresh();
        }
    }

    function update_item($inumber,$quant)
    {
        if(is_object($this->items[$inumber]))
        {
            $this->items[$inumber]->update($quant);
            $this->_refresh();
        }
    }

    function remove_item($inumber)
    {
        if(is_object($this->items[$inumber]))
        {
            unset($this->items[$inumber]);
            $this->_refresh();
        }
    }

    function clear()
    {
        unset($this->items);
        $this->_init();
    }

    function show()
    {
        reset($this->items);
        return count($this->items);
    }

	function get_name()  //this where I am trying to create a method to get to the sCartItems.
    {
        if(is_object($this->items[$inumber]))
{
$this->items[$inumber]->get_product_name();
}
    }

    function show_next_item()
    {
        if($item = each($this->items))
        {
            return $item["value"]->get_all();
        }
    }

    function sum()
    {
        if(count($this->items))
        {
             $values = array();
            // $values["cart.sum.ntotprice"] = sprintf("%0.2f", $this->ntotprice);
             $values["cart.sum.gtotprice"] = sprintf("%0.2f", $this->gtotprice);
             //foreach($this->tax as $key => $val)
             //{
                 //$values["cart.sum.tax.".$key] = sprintf("%0.2f", $val);
             //}
             return $values;
        }
        return false;
    }

    function _init()
    {
        $this->items     = array();
        $this->gtotprice = 0.00;
    }

    function _refresh()
    {
        $this->gtotprice = 0.00;
        $count           = 0;
        reset($this->items);
        foreach($this->items as $key => $val)
        {
            $this->gtotprice += $val->get_gtotprice();
            //$this->ntotprice += $val->get_ntotprice();
            //$tax = $val->get_tax();
            //$this->tax[$tax["taxqual"]] += $tax["tax"];
        }
        reset($this->items);
    }

	function itemcount(){
		$count = 0;
		foreach ($this->items as $inumber => $quant){
			$count += $quant;
		}
		return $count;
	}
}//end_of CART class

}//end_of isset

?>

thanks again for your help.

Alex

[the_Igel]

function get_name() //this where I am trying to create a method to get to the sCartItems. 
{ 
if(is_object($this->items[$inumber])) 
    { 
    $this->items[$inumber]->get_product_name(); 
    } 
} 

Oh, I see. You want to retrieve the name of $inumberth element of cart->items, aren't you?

Then you surely have to pass $inumber as the method parameter:

function get_name($inumber)
{
if (!isset($this->items[$inumber])) return '';
return $this->items[$inumber]->get_product_name();
}

This is what you need, as far as I understand.

BTW, next time you post php code to the forum, especially this long, enclose it in [ p h p ] tag, please.

[turbo99]

sorry about that.... Now I know to use the tags. I will go try it out.

Thank you,

Alex

[turbo99]

That worked great.

I was hoping I could get another solution to my next problem. I need to return the number of individual items in the shopping cart taking into account the quantities of the items as well.

I tried something like this

function itemcount() {

	$count = 0;
	foreach ($this->items as $inumber => $quant) {
		$count += $quant;
	}

	return $count;

}

but get this error.

Unsupported operand types in \lib\cart.php on line 187

Line 187 is this part of the code

$count += $quant;

any help you can give would be greatly appreciated.

Alex

[the_Igel]

Yes, and what you hoped to get? $this->items is an array of objects, so $quant is an object, not a quantity.

You should do it this way:

function itemcount() 
{
$count = 0; 
foreach ($this->items as $item) 
           $count += $item->quant;
return $count; 
} 

[turbo99]

still messing around with the output. I am trying to display the objects in the cart without success. Here is what I am trying to do. I have a cart_view page with the cart class included and this code to display the contents.

<?php

foreach ($this->items as $item){ ?>

	<tr>
		<input type="hidden" name="id[]" value="<?=$item->inumber?>">
		<td>[<a href="<?=$ME?>?func=remove&id=<?=$item->inumber?>" class="normal"><font color=#FF0000>Remove</font></a>]</td>
		<td><a href="product_details.php?id=<?=$item->inumber?>" class="normal"><?=$item->name ?></a></td>
		<td class="normal" align="right"><?=$prod->price?></td>
		<td><input type="text" size="3" name="quant[]" value="<?=$item->quant?>"></td>
		<td class="normal" align="right"><?// printf("%.2f", $total) ?></td>
	</tr>
<? } ?>

No luck. Besides my brain what am I missing?

thanks in advance,

Alex

[turbo99]

ok I figured it out....

sorry about the post. I need to use $CART->item

Alex