我应该如何更改他的脚本，以使其适用于收藏而不是Shopify中的一种产品？

Question

该脚本是Shopify中脚本编辑器应用程序随附的模板。 我需要使其工作，以便如果您从一个系列中购买一种产品，那么从该系列中可以获得另一种免费的产品。 该脚本仅适用于购买相同产品。 这是脚本：

PAID_ITEM_COUNT = 2
DISCOUNTED_ITEM_COUNT = 1

# Returns the integer amount of items that must be discounted next
# given the amount of items seen
#
def discounted_items_to_find(total_items_seen, discounted_items_seen)
  Integer(total_items_seen / (PAID_ITEM_COUNT + DISCOUNTED_ITEM_COUNT) * DISCOUNTED_ITEM_COUNT) - discounted_items_seen
end

# Partitions the items and returns the items that are to be discounted.
#
# Arguments
# ---------
#
# * cart
#   The cart to which split items will be added (typically Input.cart).
#
# * line_items
#   The selected items that are applicable for the campaign.
#
def partition(cart, line_items)
  # Sort the items by price from high to low
  sorted_items = line_items.sort_by{|line_item| line_item.variant.price}.reverse
  # Create an array of items to return
  discounted_items = []
  # Keep counters of items seen and discounted, to avoid having to recalculate on each iteration
  total_items_seen = 0
  discounted_items_seen = 0

  # Loop over all the items and find those to be discounted
  sorted_items.each do |line_item|
    total_items_seen += line_item.quantity
    # After incrementing total_items_seen, see if any items must be discounted
    count = discounted_items_to_find(total_items_seen, discounted_items_seen)
    # If there are none, skip to the next item
    next if count <= 0

    if count >= line_item.quantity
      # If the full item quantity must be discounted, add it to the items to return
      # and increment the count of discounted items
      discounted_items.push(line_item)
      discounted_items_seen += line_item.quantity
    else
      # If only part of the item must be discounted, split the item
      discounted_item = line_item.split(take: count)
      # Insert the newly-created item in the cart, right after the original item
      position = cart.line_items.find_index(line_item)
      cart.line_items.insert(position + 1, discounted_item)
      # Add it to the list of items to return
      discounted_items.push(discounted_item)
      discounted_items_seen += discounted_item.quantity
    end
  end

  # Return the items to be discounted
  discounted_items
end

eligible_items = Input.cart.line_items.select do |line_item|
  product = line_item.variant.product
  !product.gift_card? && product.id == 11380899340
end

discounted_line_items = partition(Input.cart, eligible_items)
discounted_line_items.each do |line_item|
  line_item.change_line_price(Money.zero, message: "Buy one Bolur, get one Bolur free")
end

Output.cart = Input.cart

我尝试更改，似乎是相关的代码：

eligible_items = Input.cart.line_items.select do |line_item|
  product = line_item.variant.product
  !product.gift_card? && product.id == 11380899340
end

对此：

eligible_items = Input.cart.line_items.select do |line_item|     
  product = line_item.variant.product      
  !product.gift_card? && **collection.id** == 123  
end

但我得到一个错误：

未定义的方法“收集”为主（您的购物车）

未定义方法“集合”（主要）（无客户）

Answer 1

这里有两件事：

1. line_item.variant.product没有属性collections 。 为此，您想使用line_item.product （ docs ）–（ 应该 ...请参见第二点）公开product对象的所有方法和属性。

2. 但是，在尝试做类似的事情（基于产品的折扣）时，我尝试遍历line_item.variant –并始终遇到undefined method 'product' for #<LineItem:0x7f9c97f9fff0>的undefined method 'product' for #<LineItem:0x7f9c97f9fff0>的错误。 我解释为“在购物车脚本中访问的line_items只能处于变体级别”。

所以，我想知道这是否是因为购物车仅包含变体（产品/颜色/尺寸），所以我们实际上不能按产品访问line_items ，而只能按变体访问。

我厌倦了遍历line_item.product_id ，这也会引发类似的错误。 我认为我们只需要尝试在variant级别上做一些棘手的事情。

我将查看是否可以通过变体ID访问产品...返回文档！

Answer 2

实际上，您无法进行收集，因此您需要修改脚本以使用产品类型或标签。 该脚本需要进行大量修改才能用于多种产品，而不是同一产品的多个产品