Question

通常的博客，即Posts和Comments ...

评论属于帖子......

帖子＆＃39;控制器是针对帖子的所有典型操作。

帖子＆＃39;模型has_many评论

帖子的观点显示很好......

然后我创建了注释控制器，模型和仅两个部分视图文件，即_form.html.erb和_comment.html.erb ...

在帖子的show.html.erb中，我把它们都放在这样：

<h2>Recent Comments</h2>

<%= render @comment.comments %>

<h2>Add Comments</h2>

<%= render 'comments/form' %>

当我遇到这个麻烦时，即当我点击Post＆＃39的节目链接时出现此错误...我收到此错误：

NoMethodError in Posts#show＆amp; undefined method评论＆＃39;对于nil：NilClass in reference to this line＆lt;％= render @ comment.comments％＆gt;`我不知道如何解决它......

发布控制器

class PostsController < ApplicationController


    def index 
        @posts = Post.all

        if @posts.blank? 
            flash[:alert] = "No posts have been created."
        else
            @posts 
        end
    end

    def edit 
        @post = Post.find(params[:id])
    end

    def update
        @post = Post.find(params[:id])

        if @post.update(post_params)
            flash[:notice] = "Post has been updated."
            redirect_to @post 
        else
            flash.now[:alert] = "Post has not been updated." 
            render "edit" 
        end
    end

    def create 
        @post = Post.new(post_params)

        if @post.save 
            flash[:notice] = "Post has been created."
            redirect_to @post 
        else
            flash[:notice] = "Post has not been created."
        end
    end

    def new 
        @post = Post.new
    end

    def show 
        @post = Post.find(params[:id])
    end

    def destroy
        @post = Post.find(params[:id])
        @post.destroy 

        flash[:notice] = "Post has been deleted." 
        redirect_to posts_path 
    end


    private 

    def post_params
        params.require(:post).permit(:title, :author, :body)
    end

end

评论控制器

class CommentsController < ApplicationController


    def create 
        @post = Post.find(params[:post_id])
        @comment = @post.comments.create(comment_params)
        redirect_to post_path(@post)
    end


    private 

        def comment_params
            params.require(:comment).permit(:author, :body)
        end
end

评论_comment.html.erb

<p>
    Author:
    <%= comment.author %>
</p>
<p>
    Body: 
    <%= comment.body %>
</p>

如果需要进一步的信息，请告诉我。

Answer 1

注意你的错误试图告诉你的事情：

NoMethodError in Posts#show undefined method 'comments' for nil:NilClass regarding <%= render @comment.comments %>

它告诉你NilClass没有方法comments。这意味着@comment为零。 @comment为零，因为您从未在相应的Posts#show操作中定义该变量。在那里，您只有一个@post变量。

我的猜测是你真正打算做的是：<%= render @post.comments %>

无法在帖子的展示页面中呈现部分评论文件

1 个答案: