Question

我无法在rails上更新我的评论。我想更新一篇帖子的评论。我可以生成表单并将数据检索到输入。但是当我点击提交时，显示错误。

帖子更新效果很好。但评论更新不。

Ruby -v: ruby 2.0.0p384 (2014-01-12) [x86_64-linux-gnu]
Rails -v: Rails 4.2.5.1

我的路线

/posts/:post_id/comments(.:format)          comments#index
/posts/:post_id/comments(.:format)          comments#create
/posts/:post_id/comments/new(.:format)      comments#new
/posts/:post_id/comments/:id/edit(.:format) comments#edit
/posts/:post_id/comments/:id(.:format)      comments#show
/posts/:post_id/comments/:id(.:format)      comments#update
/posts/:post_id/comments/:id(.:format)      comments#update
/posts/:post_id/comments/:id(.:format)      comments#destroy
/posts(.:format)                            posts#index
/posts(.:format)                            posts#create
/posts/new(.:format)                        posts#new
/posts/:id/edit(.:format)                   posts#edit
/posts/:id(.:format)                        posts#show
/posts/:id(.:format)                        posts#update
/posts/:id(.:format)                        posts#update
/posts/:id(.:format)                        posts#destroy
/                                           posts#index

comments_controller.rb

class CommentsController < ApplicationController
    def create
        @post = Post.find(params[:post_id])
        @comment = @post.comments.create(params[:comment].permit(:name, :body))

        redirect_to post_path(@post)
    end

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

    def update
        @post = Post.find(params[:post_id])
        @comment = Comment.find(params[:id])
        if @comment.update(params['post'].permit(:name, :body) )
            redirect_to @post
        else
            render 'edit'
        end
    end

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

edit.html.erb

<%= form_for @comment, :url => { :action => "update" } do |f| %>
    <div class="form-group">
        <%= f.label :name %><br>
        <%= f.text_field :name, class: "form-control" %>
    </div>

    <div class="form-group">
        <%= f.label :body %><br>
        <%= f.text_area :body, class: "form-control" %>
    </div>

    <div class="form-group">
        <%= f.submit %>
    </div>
<% end %>

型号：comment.rb

class Comment < ActiveRecord::Base
  belongs_to :post
end

错误

undefined method `permit' for nil:NilClass
Extracted source (around line #18):
16 @post = Post.find(params[:post_id])
17 @comment = Comment.find(params[:id])
18 if @comment.update(params['post'].permit(:name, :body) )
19     redirect_to @post
20 else
21     render 'edit'

谢谢大家！

Answer 1

您可能希望在params[:comment]

上致电许可

def update
    @post = Post.find(params[:post_id])
    @comment = Comment.find(params[:id])
    if @comment.update(params['comment'].permit(:name, :body) )
        redirect_to @post
    else
        render 'edit'
    end
end

很少有其他事情：

您需要在update_attributes上致电@comment，而不是更新
最好通过@post找到评论，而不是直接加载

@comment = @post.comments.find(params[:id])

如何在rails上更新我的评论？错误：未定义的方法`permit＆＃39;为零：NilClass

1 个答案: