未定义的局部变量或方法错误的Rails 4.2.6

Question

我已经提到RailsCasts #396从CSV，XLS xlas文件导入数据。按照railscast（滑轨3.2.9）的导入方法是

def self.import(file) 
    spreadsheet = open_spreadsheet(file) 
    header = spreadsheet.row(1) 
    (2..spreadsheet.last_row).each do |i| 
    row = Hash[[header, spreadsheet.row(i)].transpose] 
    product = find_by_id(row["id"]) || new 
    product.attributes = row.to_hash.slice(*accessible_attributes) 
    product.save! 
    end 
end 

def self.open_spreadsheet(file) 
    case File.extname(file.original_filename) 
    when ".csv" then Csv.new(file.path, nil, :ignore) 
    when ".xls" then Excel.new(file.path, nil, :ignore) 
    when ".xlsx" then Excelx.new(file.path, nil, :ignore) 
    else raise "Unknown file type: #{file.original_filename}" 
    end 
end 

但由于Rails的4倍实现强劲PARAMS我得到undefined local variable or method 'accessible_attributes'错误
所以，我抬头一看，发现这个计算器问题Rails 4 how to call accessible_attributes from Model，根据答案我试过

def attr_names 
    [user_id, last_name, first_name, last_name_kana, first_name_kana, created_at,created_by, updated_at, updated_by, del_flag] 
end 

def self.import(file) 
    spreadsheet = open_spreadsheet(file) 
    header = spreadsheet.row(1) 
    (2..spreadsheet.last_row).each do |i| 
    row = Hash[[header, spreadsheet.row(i)].transpose] 
    user = find_by(user_id: row["user_id"]) || new 
    user.attributes = row.to_hash.slice(*attr_names) 
    user.save! 
    end 
end 

def self.open_spreadsheet(file) 
    case File.extname(file.original_filename) 
    when ".csv" then Roo::CSV.new(file.path, csv_options: {encoding: "SJIS"}) 
    when ".xls" then Roo::Excel.new(file.path, nil, :ignore) 
    when ".xlsx" then Roo::Excelx.new(file.path, nil, :ignore) 
    else raise "Unknown file type: #{file.original_filename}" 
    end 
end 

还是得到同样的错误，只是这次是undefined local variable or method 'attr_names'。在此先感谢

Answer 1

作为在模型上，你应该让self.attr_names。另外，所有的方法是有自我，你可以扩展自己，就像这样：

extend self 

def attr_names 
    [user_id, last_name, first_name, last_name_kana, first_name_kana, created_at,created_by, updated_at, updated_by, del_flag] 
end 

def import(file) 
    spreadsheet = open_spreadsheet(file) 
    header = spreadsheet.row(1) 
    (2..spreadsheet.last_row).each do |i| 
    row = Hash[[header, spreadsheet.row(i)].transpose] 
    user = find_by(user_id: row["user_id"]) || new 
    user.attributes = row.to_hash.slice(*attr_names) 
    user.save! 
    end 
end 

def open_spreadsheet(file) 
    case File.extname(file.original_filename) 
    when ".csv" then Roo::CSV.new(file.path, csv_options: {encoding: "SJIS"}) 
    when ".xls" then Roo::Excel.new(file.path, nil, :ignore) 
    when ".xlsx" then Roo::Excelx.new(file.path, nil, :ignore) 
    else raise "Unknown file type: #{file.original_filename}" 
    end 
end 

Answer 2

试试这个

user.attributes = row.to_hash.slice(*column_names)