基于嵌套对象存在修改has-many中的关联(Modifing association in has-many through based on nested object existance)

 我一直在努力解决问题的最佳方法。 我有一个很多的模型，其中列表包含许多单词，单词可以在许多列表中。 关联表是Lists_word。 
 
 我正在使用accepts_nested_attributes_for：Words 
 
 单词通过列表控制器作为嵌套属性提交。 
 
 我想要实现的逻辑是： 
 
 
 
 如果用户修改了单词，我不希望在引用该单词的所有其他列表中更改该单词。 
 
 
 如果用户修改单词并且它是新单词，则创建单词并将其与用户列表相关联。 
 
 
 如果用户修改了一个单词并且它存在，则更改关联。 
 
 
 如果用户添加了单词，并且单词已经存在，则只需添加关联。 
 
 
 如果用户添加单词并且不存在则将该单词添加到集合中。 
 
 
 为了实现这一点，我在Lists模型中编写了一个create_or_associate模块。 这是有效的，但我有一种强烈的感觉，有一种更好的方法。 
 
def create_or_associate
# For each word submitted
self.words.each do |the_list|
  if the_list.word_changed? #(New and Changed)

    if the_list.id.nil? #new list word
      if Word.exists?(word: the_list.word)
        self.words << Word.where(word: the_list.word)
      else
        #new list word not in DB
        self.words << the_list
      end
    else
      # a changed list word
      if Word.exists?(word: the_list.word)
        # changed word already in DB
        self.words << Word.where(word: the_list.word)
        self.words.find(the_list.id).delete
      else
        #changed word not in DB
        new_word=Word.create(word: the_list.word)
        self.words << new_word
        self.words.find(the_list.id).delete
      end
    end
  end
end
end
 
 在我的旅行中，我没有看到任何类似的代码，这些代码响起警钟，也许我不在正确的轨道上。 
 
 谢谢你的帮助 

I've been struggling with the best way to tackle an issue for awhile now. I have a has-many through model where Lists contain many Words, Words can be in many lists. The association table is Lists_word.
 
I'm using a accepts_nested_attributes_for: Words 
 
the words are submitted via the lists controller as nested attributes.
 
The logic I wanted to implement however is:
 
 
 
If a user modifies a word I don't want that word to change in all other lists referencing that word. 
 
 
If a user modifies a word and it's a new word, then create a word and associate it to the users list.
 
 
if a user modifies a word and it exists then change the association.
 
 
if a user adds a word, and word already exists then just add the association.
 
 
if a user adds a word and it doesn’t exist add the word to the collection.
 
 
To accomplish this I wrote a create_or_associate module in the Lists model. This works, however I have a strong feeling that there is a better way.
 
def create_or_associate
# For each word submitted
self.words.each do |the_list|
  if the_list.word_changed? #(New and Changed)

    if the_list.id.nil? #new list word
      if Word.exists?(word: the_list.word)
        self.words << Word.where(word: the_list.word)
      else
        #new list word not in DB
        self.words << the_list
      end
    else
      # a changed list word
      if Word.exists?(word: the_list.word)
        # changed word already in DB
        self.words << Word.where(word: the_list.word)
        self.words.find(the_list.id).delete
      else
        #changed word not in DB
        new_word=Word.create(word: the_list.word)
        self.words << new_word
        self.words.find(the_list.id).delete
      end
    end
  end
end
end
 
I've not seen any similar code in my travels, which rings alarm bells that perhaps I'm not on the right track.
 
Thanks for any help

原文：https://stackoverflow.com/questions/20592126