如何使用 Rails 3 显示博客应用程序中的所有帖子？

Question

我正在尝试在我的应用程序中实现博客应用程序。但是保存帖子后出现以下错误。

错误：

NoMethodError in Homes#blog

Showing C:/Site/library_management1/app/views/homes/blog.html.erb where line #19 raised:

undefined method `name' for #<Array:0x21896a0>

实际上我的博客实现故事是这样的。当登录用户在所需位置添加他的姓名和评论并单击提交按钮时，所有博客都将保存并显示。所有登录用户都应该看到的所有评论都属于此app.假设一个用户想要回复/编辑那么他/她可以这样做。

我的代码如下。

views/homes/blog.html.erb:

<% if current_user %>
<div class="totaldiv">
  <div class="navdiv"><span>STUDENT INFORMATION</span><span>Logged in as <%= current_user.email %></span></div>
  <div class="wrapper">
  <div id="leftsidebtn">
 <ul>
  <li><a href="/homes/issuebooks">Book issue</a></li>
   <li><a href="/homes/availablebooks">Books Available</a></li>
   <li><a href="/homes/magazines?user_id=<%= current_user.id %>">Magazines Purchase</a></li>
  <li><a href="/sessions/removeuser">Log Out</a></li>
 </ul>  
</div>
  </div>
  <div class="restdiv" id="ex3" >
<center>
 <%= form_for :blogs,:url => {:action => 'savecomments',:id => current_user.id } do |f| %>
 <p>
  <label for="name">Name:</label>
  <%= f.text_field :name,placeholder:"Enter your name" %>
</p>
<p>
  <label for="Comment">Comment:</label>
  <%= f.text_area :body,:class => "blog-navigation",placeholder:"Type your comment here" %>
</p>
<p>
  <%= f.submit "Add Comments",:class =>"btn btn-success" %>
</p>
 <% end %>
 <% if params[:id] %>
 <h1>Comments</h1>
 <% @blogs.each do |blog| %>
<div class="blog-site">
<div class="name-site">
 <%= blog.name %>
</div>
<div class="message-site">
  <%= blog.body %>
</div>
<div class="reply-site">
  <%= link_to 'Replay',homes_blog_path %>
</div>
</div>
<% end %>
<% end %>
</center>
  </div>
</div>
<% end %>

控制器/homes_controller.rb：

class HomesController < ApplicationController
     before_filter :authenticate_admin!,only: [:admin]
    def index

    end
    def admin

    end
    def managebooks
        @books=Book.new
        if params[:id]
            @books=Book.find(params[:id])
            @book=Book.all
        end
    end
    def savebooks
        @books=Book.new(params[:books])
        if @books.save
            flash[:notice]="Data has submitted successfully"
            flash[:color]="valid"
            redirect_to :action => 'managebooks',:id => @books.id
        else
            flash[:notice]="Data couldnot submitted successfully"
            flash[:color]="invalid"
            render 'managebooks'
        end
    end
    def remove
        @books=Book.find(params[:id])
        @books.destroy
    end
    def books

    end
    def showbooks
        @books=Book.all
    end
    def searchbooks
        @books=Book.all
    end
    def member
        @users=User.new
    end
    def registration
        @users=User.new
    end
    def savedata
        @users=User.new(params[:users])
        if @users.save
            flash[:notice]="Data has submitted successfully"
            flash[:color]="valid"
            redirect_to :action => 'member'
        else
            flash[:notice]="Data could not submitted successfully"
            flash[:color]="invalid"
            render 'registration'
        end
    end
    def issuebooks
        @issues=Issue.new
    end
    def savedissuebooks
        @issues=Issue.new(params[:issues])
        if @issues.save
            flash[:notice]="information has saved successfully"
            flash[:color]="valid"
            redirect_to :action => 'member'
        else
            flash[:notice]="Data couldnot saved"
            flash[:color]="invalid"
            render 'issuebooks'
        end
    end
    def availablebooks

        @books=Book.all
    end
    def userissues
        @issues=Issue.all
    end
    def magazine
        @magazines=Magazine.new
    end
    def savemagazines
        @users=User.find(params[:id])
        @magazines=Magazine.new(params[:magazines])
        @[email protected]
        if @magazines.save
            flash[:notice]="Data submitted successfully"
            flash[:color]="valid"
            redirect_to :action => "member"
        else
            flash[:notice]="Data could not saved"
            flash[:color]="invalid"
            render 'magazines'
        end
    end
    def magazineissue
        @magazines=Magazine.all
        @users=User.find @magazines.first.user_id
    end
    def blog
        if params[:id]
            @blogs=Blog.find(params[:id])
            @blogs=Blog.all
        else
        @blogs=Blog.new
        end
    end
    def savecomments
        @users=User.find(params[:id])
        @blogs=Blog.new(params[:blogs])
        @[email protected]
        if @blogs.save
            flash[:notice]="Comment has been posted successfully"
            flash[:color]="valid"
            redirect_to :action => "blog",:id => params[:id]
        else
            flash[:notice]="Comment could not saved"
            flash[:color]="invalid"
            render 'blog'
        end
    end
end

模型/blog.rb

class Blog < ActiveRecord::Base
  attr_accessible :body, :name
  validates :name, :presence => true, :length => {:in => 3..10}
  belongs_to :user
end

请检查我的所有代码，让我知道我在哪里犯了错误，并请帮助我根据上面解释的我的故事正确地制作这个博客应用程序。

Answer 1

我想向您推荐一篇博客文章，解释如何自己调试 Rails 应用程序：http://nofail.de/2013/10/debugging-rails-applications-in-development/

了解 Rails 错误消息试图告诉您的内容非常重要：

数组的未定义方法

name

：0x21896a0

它正在某个数组上调用

.name

。

显示 C:/Site/library_management1/app/views/homes/blog.html.erb 其中第 19 行提出：

它在第 19 行的

blog.html.erb

中执行此操作，我想这就是这里的部分：

 <%= form_for :blogs,:url => {:action => 'savecomments',:id => current_user.id } do |f| %>
 <p>
  <label for="name">Name:</label>
  <%= f.text_field :name,placeholder:"Enter your name" %>
</p>

此表单尝试在您定义为

.name

的嵌套对象上调用

:blogs

，以便获取

:name

的

f.text_field

属性。那么表单尝试使用的对象是什么？

Homes 中没有方法错误#blog

查看

Homes#blog

的控制器代码，看看可能的表单对象来自哪里：

def blog
    if params[:id]
        @blogs=Blog.find(params[:id])
        @blogs=Blog.all
    else
    @blogs=Blog.new
    end
end

所以唯一可能是数组的是

@blogs = Blog.all

。这段代码对我来说似乎没有多大意义。为什么你要做一个

Blog.find

只是为了将其替换为下一行中的

Blog.all

？