Rails 5：嵌套表单和现有关联对象 [英] Rails 5: Nested forms and existing associated objects

问题描述

我对Rails比较陌生，因此如果发现这是一个非常幼稚的问题，请原谅我。 ：]

I'm relatively new to Rails so please forgive me if this turns out to be quite a naive question. :]

我有两个可以标记的模型：收藏和视频。我通过带有多态关联的 Tag 模型和<$ c $ has_many：through 关联到标记。所有这些都能完美地工作。

I have two models that can be tagged: Collection and Video. I support this via a Tag model with a polymorphic association, and a has_many :through association to Tagging. All this works perfectly.

我很难弄清楚的是如何设置视图以适应这种情况。我知道，如果我仅创建或更新与单个模型唯一关联的标签，则可以使用简单的表单并将 accepts_nested_attributes_for 添加到我的模型中，但是问题是我我必须首先检查标记是否存在，并仅在不存在标记时创建它，否则，只需将现有标记与 new 视频或收藏集相关联即可。显然，我可以在控制器中手动执行此操作，但是由于Rails提供了一种自动创建和更新关联对象的机制，我想知道它是否提供了与关联现有对象类似的功能？

What I'm having a hard time figuring out is how to set up the views to accommodate this. I know that if I were only creating or updating tags that are uniquely associated with a single model then I could use a simple form and add accepts_nested_attributes_for to my model, but the problem I'm having is that I want to first check for the existence of a tag, and only create it if it doesn't exist, otherwise just associate the existing tag with the new video or collection. Obviously I could do this manually in the controller, but since Rails provides a mechanism for creating and updating associated objects automatically, I wondered if it provided anything similar for associating existing objects?

此外，我不确定是否应该嵌套 tags 资源并在 TagsController 中集中处理，还是是否应该从拥有对象的控制器管理标签，例如 VideosController 。

Also, I'm not sure whether I should nest the tags resource and handle this centrally in a TagsController, or whether I should manage the tags from the owning object's controller, for instance VideosController.

任何帮助或建议都会

推荐答案

您需要手动执行此操作，这不是很多代码。

you need to do it manually, it's not that much code.

类似问题

基本上，您需要在控制器中使用 find_or_create_by （文档）和 fields_for （文档）在您的收藏夹和视频视图中。

Basically, you'll need find_or_create_by in your controller (doc) and fields_for (doc) in your Collection and Video views.

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