Rails的AR记录包括“新的”未保存记录 [英] Rails AR record includes 'new' unsaved record

问题描述

我有一个'文章'表演动作的图。

I have a view for an 'article' show action.

文章有意见。

该视图显示： 一）文章 B）评论 c）新的评论表单

The view displays: a) article b) comments c) new comment form

我的控制器操作：

def show
  @article = Article.find(params[:id])
  @comments = @article.comments
  @comment = @comments.new
end

视图使用部分显示的评论。

The view displays the comments using a partial.

<%= render @comments %>

在通过@comments循环我发现列表中也包含了控制器动作的新纪录。我能避免使用显示该行：

When looping through @comments I am finding the list also contains the new record from the controller action. I can avoid displaying this row using:

<% if !comment.new_record? %>
  ...
<% end %>

我是这样做不对，或这是预期的行为？

Am I doing this wrong or is this the expected behaviour?

推荐答案

由于你如何创建新的注释的是预计。你基本上添加一个新的空注释您 @ article.comments 您呈现他们的观点了。您的解决方案是有道理的，但或者，您可以通过不会分配 @article 新 @comment 控制器里面显示操作。

Yes it is expected because of how you are creating the new Comment. You are basically adding a new empty Comment to your @article.comments before you render them in the view. Your solution makes sense but alternatively you could avoid the issue by not assigning the @article to the new @comment inside your controller show action.

所以不是 @comment = @ comments.new 你会做 @comment = Comment.new 。然后，你的表格里面的 @comment 你会添加一个字段为的article_id 。

So instead of @comment = @comments.new you would do @comment = Comment.new. Then, inside your form for the @comment you would add a field for the article_id.

<%= f.hidden_field :article_id, :value => @article.id %>

这将让你保持你的 Comment.create 行动的关系。

This will allow you to maintain the relationship in your Comment.create action.

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