Carrinho de compras em PHP para responder em: http://forum.imasters.com.br/topic/525247-carrinho-de-compras-php/

carrinho-de-compras.php

<?php

class Cart
{
    public $CookieName = 'carrinho';
	
    public function __construct() {
        if(!$this->getCookie()) {
			return;
		}
		
        $Products = array();
		
        foreach($this->getCookie() as $Key => $Value) {
            if($Value['product_amount']!==0) {
            	$Products[$Key] = $Value;
			}
        }
        $this->setCookie($Products);
    }
	
    /**
    * 
    * string $Value: Valor do cookie
    * int $Days: Dias em que o cookie estará válido
    * 
    **/
    public function setCookie(string $Value, int $Days=7) {
        setcookie($this->CookieName, serialize($Value), ($Days*24*60*60), '/', "", "", true); 
    }
    
    public function getCookie():string {
        return isset($_COOKIE[$this->CookieName]) ? unserialize($_COOKIE[$this->CookieName]): null;
    }
	
    public function getProductById(int $ID):array {
		return $this->getCookie()[$ID] ?? null;
    }
	
    public function removeProductById($ID) {
        $Products = $this->getCookie();
        unset($Products["products_{$ID}"]);
        $this->setCookie($Products);
    }
    
    /**
    * 
    * Remove um item de um produto
    * int $ID: Id do produto
    * 
    **/
    public function removeItem(int $ID) {
        $Product = $this->getProductById($ID);
        if(!$Product) {
			return;
		}
		
        if(1==$Product['product_amount']) {
            return $this->removeProductById($ID);
        }
		
        $Products = $this->getCookie();
        $Products["products_{$ID}"]["product_amount"]--;
        $this->setCookie($Products);
    }
	
    public function addItem(int $ID, int $Amount=1) {
        $Products = $this->getCookie();
        if(!isset($Products["products_{$ID}"])) {
			return;
		}
        $Products["products_{$ID}"]['product_amount'] += (int) $Amount;
        $this->setCookie($Products);
    }
	
    public function toHTML()
    {
		if(!count($this->getCookie()))
		{
			return array('<b>Carrinho vazio.</b>');
		}
		
        $Products = $this->getCookie();
		$Table    = array();
        $Total    = 0;
		
        foreach($Products as $Key => $Value) {
            $Total += $SubTotal = number_format($Value['product_price'] * $Value['product_amount'] , 2, ',', '.');
            
            $Table[] = array(
                sprintf("Código %s - %s R$ %s - (Qtd %s) <br/>", $Value['product_code'], $Value['product_name'], number_format($Value['product_price'], $Value['product_amount']),
                sprintf("%s - %s <br/>", $Value['product_options']['tamanho'], $Value['product_options']['cor']),
                sprintf("R$ %s", $SubTotal)
            );
        }
		
        $Table[] = sprintf("Itens: %s, Total: R$ %s", count($Products), number_format($Total, 2, ',', '.'));
        
        return $Table;
    }
}