如何将评论表单与正确的帖子相关联

Question

我有用户/微博/评论模型，用户可以在其中评论别人的微博。在每个帖子下面都会显示一个文本字段，这样用户就可以输入评论，但是我很难找到微博Id。我认为问题出在我的form_for注释或控制器中，但我不是很确定。希望能帮上忙谢谢。

错误:找不到没有ID的微帖子

型号：

User Model: has many microposts, has many comments
Micropost Model: belongs to user, has many comments
Comment Model: belongs to micropost, belongs to user

用户控制器：

def show #(the profile page where all the posts and comments are)
  @user = User.find(params[:id])
  @microposts = @user.microposts.paginate(page: params[:page])
  @micropost  = current_user.microposts.build if signed_in?
  @comments = @micropost.comments
  @comment = current_user.comments.build(:micropost => @micropost) if signed_in?
end

注释控制器：

def create
  @micropost = Micropost.find(params[:id])
  @comment = current_user.comments.build(:micropost => @micropost) #can someone explain what happens in the parentheses? 
  @comment.user = current_user
  @comment.save
  redirect_to :back
end

查看/注释/_注释_表单：

<%= form_for(@comment) do |f| %>
  <div id="comment_field">
    <%= f.text_field :content, placeholder: "Say Something..." %>
  </div>
<% end %>

路由：

resources :users
resources :microposts, only: [:create, :destroy]
resources :comments, only: [:create, :destroy]

Answer 1

只需为micropost_id添加一个隐藏字段

<%= form_for(@comment) do |f| %>
  <%= f.hidden_field :micropost_id, value: @micropost.id %>
  <div id="comment_field">
    <%= f.text_field :content, placeholder: "Say Something..." %>
  </div>
<% end %>

更新:传递micropost_id而不对控制器进行任何更改

根据您的comments控制器，您会发现在提交表单时缺少基于params[:id]的micropost。下面的代码解决了这个问题。但是，我建议您查看嵌套资源，这将使控制器代码更美观、更流畅。

<%= form_for @comment do |f| %>
  <%= hidden_field_tag :id, @micropost.id %>
  <div id="comment_field">
    <%= f.text_field :content, placeholder: "Say Something..." %>
  </div>
<% end %>

或更新表单的action

<%= form_for @comment, url: comments_path(id: @micropost.id) do |f| %>
  <div id="comment_field">
    <%= f.text_field :content, placeholder: "Say Something..." %>
  </div>
<% end %>

更新:对注释控制器进行编辑

# view
<%= form_for @comment do |f| %>
  <%= hidden_field_tag :micropost_id, @micropost.id %>
  <div id="comment_field">
    <%= f.text_field :content, placeholder: "Say Something..." %>
  </div>
<% end %>

# comments_controller.rb

def create
  @micropost = Micropost.find params[:micropost_id]
  @comment = current_user.comments.build
  @comment.micropost = @micropost
  @comment.save
end

Answer 2

你应该这样设置你的评论资源：

resources :users
resources :microposts, only: [:create, :destroy] do
  resources :comments, only: [:create, :destroy]
end

以上资源称为嵌套资源。在你的例子中，评论总是与微博相关，你应该将评论资源嵌套到microposts和评论控制器中：

def create
  @micropost = Micropost.find(params[:id])
  @comment = current_user.comments.build(:micropost => @micropost) #can someone explain what happens in the parentheses?
  @comment.save
  redirect_to :back
end

上面的构建方法创建了一个新的注释模型的对象/实例，因为您已经使用了current_user.comments，这意味着该对象将自动拥有user_id = current_user.id，您不需要再次指定它。和'build(:micropost => @micropost)‘会将micropost's id添加到@comment对象。