如何根据购物车中的产品以及与这些产品链接的运输选项，从购物车中删除运输选项

Question

我有一个市场，卖家可以销售多个产品并分别指定运输选项，将运输选项与产品联系在一个多到多的关系中。

在购物车控制器中，我试图明智地删除运输选项，这样卖家就不会因为运输成本而剩下太少的钱。

举个例子，考虑一个购物车，里面有两个产品。卖方选择了每种产品一种运输方案：

$products = array(
    array(
        'id' => 1,
        'name' => 'Lightweight widget',
        'shipping_option_ids' => array(
            1
        )
    ),
    array(
        'id' => 2,
        'name' => 'Heavyweight widget',
        'shipping_option_ids' => array(
            2
        )
    )
);

以下是两种运输选择：

$shipping_options = array(
    array(
        'id' => 1,
        'name' => 'Cheap shipping option',
        'price' => 100
    ),
    array(
        'id' => 2,
        'name' => 'Expensive shipping option',
        'price' => 200
    )
);

因此，我们有两个产品，每个连接到不同的航运选择。使用昂贵的运输选项，这两种产品可以在同一个包裹中运送。

现在，我需要从送货选项数组中删除廉价的送货选项。这将使客户只有一个选择的航运选择-昂贵的一个。

泛化

条件

• 购物车中没有至少一个共同运输选项的两个或多个产品。 动作
• 删除所有运输选项，但那些链接到产品与最昂贵的运输选项。

Answer 1

我用以下方式解决了这个问题：

// Prepare for removal procedure
foreach ($store['shipping_options'] as &$shipping_option)
{
    $shipping_option['removal_candidate'] = FALSE;
}
unset($shipping_option);

// Label shipping options that aren't linked to all products:
foreach ($products as $product)
{
    if (!in_array($shipping_option['id'], $product['shipping_option_ids']))
    {
        $shipping_option['removal_candidate'] = TRUE;
    }
}

$number_of_shipping_options = count($shipping_options);

// Loop through each shipping option:
for ($i = 0; $i < $number_of_shipping_options; $i++)
{
    $shipping_option_a = $shipping_options[$i];

    // Compare each shipping option with each of the other shipping options:
    foreach ($shipping_options as $key => $shipping_option_b)
    {
        // Compare different shipping options only:
        if ($shipping_option_a['id'] != $shipping_option_b['id'])
        {
            // Remove the shipping option with the lowest price:
            if ($shipping_option_a['price'] < $shipping_option_b['price'])
            {
                if ($shipping_option_a['removal_candidate'])
                {
                    unset($store['shipping_options'][$i]);
                    $shipping_options_removed = TRUE;
                    $number_of_shipping_options = count($store['shipping_options']);
                }
                elseif ($shipping_option_a['price'] > $shipping_option_b['price'])
                {
                    if ($shipping_option_b['removal_candidate'])
                    {
                        unset($store['shipping_options'][$key]);
                        $shipping_options_removed = TRUE;
                        $number_of_shipping_options = count($store['shipping_options']);
                    }
                }
            }
        }
    }
    // Refresh key numbers:
    $store['shipping_options'] = array_values($store['shipping_options']);
}