Question

新主题表单包含标题，说明和首发内容的字段。

提交后，应创建包含标题，说明，用户ID和论坛ID值的主题，以及包含内容，用户ID和主题ID值的帖子。但是，帖子的内容并没有保存到表中，尽管用户ID和主题ID都是。

视图/主题/ _form.html.erb

<%= form_for(@topic) do |f| %>
  <% if @topic.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@topic.errors.count, "error") %> prohibited this topic from being saved:</h2>

      <ul>
      <% @topic.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <% if params[:forum] %><input type="hidden" id="topic_forum_id" name="topic[forum_id]" value="<%= params[:forum] %>" /><% end %>
  <div class="field">
    <%= f.label :title %><br>
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :description %><br>
    <%= f.text_area :description %>
  </div>
  <div class="field">
    <textarea name="post[content]" class="form-control" cols="80" rows="20"><%= @post.content %></textarea>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

控制器/ topics_controller.rb

def new
  @topic = Topic.new
  @post = Post.new
end

def create
  user_id = current_user.id || 1 # temporary assignment until guest account generated
  @topic = Topic.new(title: params[:topic][:title], description: params[:topic][:description], forum_id: params[:topic][:forum_id], user_id: user_id)
  if @topic.save
    @post = Post.new(content: params[:post][:content], topic_id: @topic.id, user_id: user_id)
    if @post.save
      flash[:notice] = "Successfully created topic."
      redirect_to "/topics/#{@topic.id}"
    else
      render action: 'new'
    end
  else
    render action: 'new
  end
end

模型/ post.rb

class Post < ActiveRecord::Base
  belongs_to :topic
  belongs_to :user

  has_many :replies, :dependent => :nullify

  validates :content, presence: true

  attr_accessor :content
end

模型/ topic.rb

class Topic < ActiveRecord::Base
  belongs_to :forum
  belongs_to :user

  has_many :posts, :dependent => :destroy

  validates :title, presence: true, length: { maximum: 255 }
  validates :user_id, presence: true
  validates :forum_id, presence: true
end

Answer 1

我会像下面这样实现accepsts_nested_attributes的概念来处理你的情况。

#topic.rb

class Topic < ActiveRecord::Base
  belongs_to :forum
  belongs_to :user

  has_many :posts, :dependent => :destroy
  accepts_nested_attributes_for :posts
  validates :title, presence: true, length: { maximum: 255 }
  validates :user_id, presence: true
  validates :forum_id, presence: true
end

#topics_controller.rb

def new
  @topic = Topic.new
  @post = @topic.posts.build
end

def create
  user_id = current_user.id || 1 # temporary assignment until guest account generated
  @topic = Topic.new(params[:topic])
  if @topic.save
    @post = Post.new(params[:post])
    @post.topic_id = @topic.id
    @post.user_id = user_id
     if @post.save
      flash[:notice] = "Successfully created topic."
      redirect_to @topic
     else
      render action: 'new'
     end
   else
     render action: 'new'
   end
end

#form
<%= form_for(@topic) do |f| %>
  <% if @topic.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@topic.errors.count, "error") %> prohibited this topic from being saved:</h2>

      <ul>
      <% @topic.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <% if params[:forum] %><input type="hidden" id="topic_forum_id" name="topic[forum_id]" value="<%= params[:forum] %>" /><% end %>
  <div class="field">
    <%= f.label :title %><br>
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :description %><br>
    <%= f.text_area :description %>
  </div>
  <%= f.fields_for @post do |p| %>
  <div class="field">
    <%= p.text_area :content, cols: 80, rows: 20, class: "form-control" %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

保存：主题创建时的第一篇文章的内容，包含帖子和主题模型

1 个答案: