blocks|key|1949080|text|试着按以下方式做某事：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1949081|current_user.todo_lists+<<+TodoList.new(params[:todo_list])|code-block|syntax|javascript|1949082|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Try doing something along the lines of:

<pre><code>current_user.todo_lists &lt;&lt; TodoList.new(params[:todo_list])
</code></pre>

blocks|key|1949115|text|我让它发挥作用..。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1949116|一开始我有：|1949117|@todo_list+=+@user.todo_lists.build+params[:todo_list]
@todo_list.save!|code-block|syntax|javascript|1949118|当TodoList简单地使用belongs_to用户时，这是有效的，但是当它是一个多到多的关系时，就不会起作用了。当我改变关系的时候.|1949119|@todo_list+=+@user.todo_lists.build+params[:todo_list]
@user.save!|1949120|这保存了@user、join和@todo_list。|1949121|很明显，我想，但是我想知道最初的例子是否也应该|1949122|current_user.save!|1949123|而不是|1949124|@todo_list.save!|1949125|我认为构建的思想是，当您保存父程序时，它会验证和保存关联，那么钢轨道的示例是否忽略了这一点呢？或者更有可能是我？|offset|length|style|BOLD|1949126|entityMap|0|LINK|mutability|MUTABLE|url|http://www.therailsway.com/2007/3/26/association-proxies-are-your-friend^0|0|0|0|0|0|0|0|0|0|0|3|2|V|3|0|0^^$0|@$1|2|3|4|5|6|7|1A|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1B|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|1C|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|1D|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|1E|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|1F|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|1G|8|@]|9|@]|A|$]]|$1|Q|3|R|5|F|7|1H|8|@]|9|@]|A|$G|H]]|$1|S|3|T|5|6|7|1I|8|@]|9|@]|A|$]]|$1|U|3|V|5|F|7|1J|8|@]|9|@]|A|$G|H]]|$1|W|3|X|5|6|7|1K|8|@$Y|1L|Z|1M|10|11]]|9|@$Y|1N|Z|1O|1|1P]]|A|$]]|$1|12|3|-4|5|6|7|1Q|8|@]|9|@]|A|$]]]|13|$14|$5|15|16|17|A|$18|19]]]]

I got it working...

At first I had:

<pre><code>@todo_list = @user.todo_lists.build params[:todo_list]
@todo_list.save!
</code></pre>

This works when TodoList simply belongs_to User but not when it's a many-to-many relationship. When I changed the relationship I had to do...

<pre><code>@todo_list = @user.todo_lists.build params[:todo_list]
@user.save!
</code></pre>

This saved the @user, the join and the @todo_list.

Obvious I suppose but then I wonder if the original example should also

<pre><code>current_user.save!
</code></pre>

instead of 

<pre><code>@todo_list.save!
</code></pre>

I thought the idea behind build was that it validates and saves the associations when you save the parent so does the example at <a href="http://www.therailsway.com/2007/3/26/association-proxies-are-your-friend" rel="nofollow noreferrer">Rails Way</a> miss the point? or more likely am I?

Taking this article as a starting point:

<a href="http://www.therailsway.com/2007/3/26/association-proxies-are-your-friend" rel="nofollow noreferrer">Rails Way Blog - Association Proxies</a>

and looking specifically at

<pre><code>def create
 @todo_list = current_user.todo_lists.build params[:todo_list]
 if @todo_list.save
 redirect_to todo_list_url(@todo_list)
 else
 render :action=&gt;'new'
 end
end
</code></pre>

This is a way of making sure you assign ownership to the user

BUT supposing the ToDo list was a many-many relationship associated in a has_many through i.e.

<pre><code>def User &lt; AR:Base
 has_many :user_todos
 has_many :todo_lists, :through =&gt; :user_todos
end
</code></pre>

At this point...

<pre><code>@todo_list = current_user.todo_lists.build params[:todo_list]
</code></pre>

still works but only the todo_list is saved and not the join. How can I get the joy of association proxies without having lots of nested if/else should the join or Todo instance not validate when saved.

I was thinking of something along the lines of...

<pre><code>@todo_list = cu.user_todos.build.build_to_do(params[:todo_list])
</code></pre>

but as I mentioned above the user_todos don't get saved.

Your help is greatly appreciated!

Kevin.

Building association proxies with through

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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以本文为起点：并特别注视着def create  @todo_list = current_user.todo_lists.build params[:todo_list]  if @todo_list.save    redirect_to todo_list_url(@todo_list)  else    ren...

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