Question

跟进此screencast，如果2..3记录

，它会在某处返回Product

def save
    puts "--- imported_products: #{imported_products.inspect}"
    // --- imported_products: 2..3
    if imported_products.map(&:valid?).all?
      imported_products.each(&:save!)
      true
    else
      imported_products.each_with_index do |product, index|
        product.errors.full_messages.each do |message|
          errors.add :base, "Row #{index+2}: #{message}"
        end
      end
      false
    end
 end

 def imported_products
   @imported_products ||= load_imported_products
 end

 def load_imported_products
   spreadsheet = open_spreadsheet
   header = spreadsheet.row(1)
   (2..spreadsheet.last_row).each do |i|
     row = Hash[[header, spreadsheet.row(i)].transpose]
     product = Product.find_by_id(row['id']) || Product.new
     product.attributes = row.to_hash.slice(*accessible_attributes)
     product
   end
 end

Answer 1

您的load_imported_products方法包含each块。该块是方法的最后一行，因此块的返回值成为方法的返回值。

尝试以下方法：

def load_imported_products
  spreadsheet = open_spreadsheet
  header = spreadsheet.row(1)
  products = []
  (2..spreadsheet.last_row).each do |i|
    row = Hash[[header, spreadsheet.row(i)].transpose]
    product = Product.find_by_id(row['id']) || Product.new
    product.attributes = row.to_hash.slice(*accessible_attributes)
    products << product
  end
  products
end

Answer 2

或使用地图

def load_imported_products
  spreadsheet = open_spreadsheet
  header = spreadsheet.row(1)
  products = (2..spreadsheet.last_row).map do |i|
    row = Hash[[header, spreadsheet.row(i)].transpose]
    product = Product.find(row['id'].to_i) || Product.new
    product.attributes = row.to_hash.slice(*accessible_attributes)
    product
  end
end

find方法使用id时也不需要find_by_id，但我强制它为nil整数或存储为string。

Answer 3

如果您正在讨论load_imported_products方法，那么尝试将每个产品添加到数组中，然后返回该数组。

我不确定该方法究竟返回了什么，但您可能需要显式返回一组产品。

所以

def load_imported_products
   products = []
   spreadsheet = open_spreadsheet
   header = spreadsheet.row(1)
   (2..spreadsheet.last_row).each do |i|
     row = Hash[[header, spreadsheet.row(i)].transpose]
     product = Product.find_by_id(row['id']) || Product.new
     product.attributes = row.to_hash.slice(*accessible_attributes)
     products << product
   end
   return products
 end

Ruby块返回不合适的值

3 个答案: