php - Magento: Is a certain product in the cart? -

on list.phtml page, want php script able tell whether product in cart, based on it's sku.

so conditional theoretically this:

$_sku = 123;    if($_sku->isinbasket() == true){     echo 'product: ' . $_sku . ' in cart'; } 

how can achieved realistically?

fetch data checkout session , check product exits in current session

$quote = mage::getsingleton('checkout/session')->getquote();  $foundincart = false; foreach($quote->getallvisibleitems() $item) {     if ($item->getdata('sku') == $_sku) {         $foundincart = true;         break;     } } 

it bad check sku.

because of whenever configurable product cart simple product sku in db.

so need check using product id.for case need find id of $sku mage::getmodel('catalog')->loadbysku($sku); before start of products foreach loop.

$_skupid=''; $matchpro=mage::getmodel('catalog')->loadbysku($sku); if($matchpro->getid()){     $_skupid=$matchpro->getid(); }   $quote = mage::getsingleton('checkout/session')->getquote();  $foundincart = false; foreach($quote->getallvisibleitems() $item) {     if ($item->getdata('prodduct_id') == $_skupid) {         $foundincart = true;         break;     } }