未定义的方法 '-' 用于"books, children" ：字符串

Question

PROBLEM - undefined method ' -' for "books, children":String

'acts_as_taggable_on_steroids'已经有一段时间没有维护了。它以前工作得很好，直到最近。现在，当我尝试创建或更新标签时，我得到一个错误消息->未定义方法' -' for "books, children":String

                  --- Codings ----

acts_as_taggable.rb

   1. module ActiveRecord #:nodoc:
   2. module Acts #:nodoc:
   3.  module Taggable #:nodoc:
   4.    def self.included(base)
   5.  base.extend(ClassMethods)
   6. end

   7. module ClassMethods
   8.  def acts_as_taggable
   9.   has_many :taggings, :as => :taggable, :dependent => :destroy
   10.  has_many :tags, :through => :taggings
   11. before_save :save_cached_tag_list
   12. after_create :save_tags  
   13. after_update :save_tags   
   14.  include ActiveRecord::Acts::Taggable::InstanceMethods
   15. extend ActiveRecord::Acts::Taggable::SingletonMethods
   16. alias_method_chain :reload, :tag_list

::::::::::::::::::::::::

   17. def save_tags
   18.       return unless @tag_list
   19.     new_tag_names = @tag_list - tags.map(&:name)
   20.   old_tags = tags.reject { |tag| @tag_list.include?(tag.name) }
   21. self.class.transaction do
   22.  if old_tags.any?
   23.  taggings.find(:all, :conditions => ["tag_id IN (?)", 
   24. old_tags.map(&:id)]).each(&:destroy)
   25.       taggings.reset
   26.    end
   27.  new_tag_names.each do |new_tag_name|
   28.  tags << Tag.find_or_create_by_name(new_tag_name)
   29. end
   30.  end
   31.  true
   32. end
   33.  end

注意:第19行导致了这个问题!

tag.rb

    1. class Tag < ActiveRecord::Base
    2. attr_accessible :name
    3.  has_many :taggings, :dependent => :destroy
    4.  validates :name, :presence=>true
    5. validates_uniqueness_of :name
    6.  def self.find_or_create_by_name(name)
    7.  Tag.where(:name=>name).first_or_create do |tag|
    8.  tag.name = name
    9. end
    10. end

任何帮助都会很感激。谢谢你。

Answer 1

@tag_list在哪里创建?原来是数组，现在是字符串

如果您想要快速修复，您可以将第19行更改为:

new_tag_names = @tag_list.split(', ') - tags.map(&:name)