undefined方法 avatar?' for nil:NilClass undefined method name'为nil：NilClass
嗨，我在部分中收到以下错误 . 我列出这两个的原因是因为在评论出导致第一条错误消息的行之后，我得到了第二个错误，这导致我认为问题不是专门用“avatar”或“name”，而是用其他东西，尽管我不知道是什么 . 在rails控制台中，我可以在注释上调用用户和名称 . 如果重要，我还使用Faker播种数据库 . 这是部分的 .
<%= content_tag :div, class: 'media', id: "comment-#{comment.id}" do %>
<%= link_to '#', class: 'pull-left' do %>
<%= image_tag(comment.user.avatar.small.url) if comment.user.avatar? %>
<% end %>
<div class="media-body">
<small>
<%= comment.user.name %> commented <%= time_ago_in_words(comment.created_at) %> ago
<% if policy(comment).destroy? %>
| <%= link_to "Delete", [@topic, @post, comment], method: :delete %>
<% end %>
</small>
<p><%= comment.body %></p>
</div>
<% end %>
另外，请看渲染 .
<div class="col-md-4">
<% if policy(Comment.new).create? %>
<h4>Leave a comment</h4>
<%= render partial: 'comments/comment', locals: { topic: @topic, post: @post, comment: @comment } %>
<% end %>
</div>
以下是我的用户模型和comments_controller
class UsersController < ApplicationController
before_filter :authenticate_user!
def update
if current_user.update_attributes(user_params)
flash[:notice] = "User information updated"
redirect_to edit_user_registration_path(current_user)
else
render "devise/registrations/edit"
end
end
private
def user_params
params.require(:user).permit(:name, :avatar)
end
end
Comments_controller
def create
@topic = Topic.find(params[:topic_id])
@post = @topic.posts.find(params[:post_id])
@comments = @post.comments
@comment = current_user.comments.build(comment_params)
@comment.post = @post
@new_comment = Comment.new
authorize @comment
if @comment.save
redirect_to [@topic, @post], notice: "Comment was submitted successfully."
else
flash[:error] = "There was an error submitting the comment. Please try again."
end
end
我已经重置了数据库，但无济于事 . 坚持问题是什么 . 谢谢你的帮助 .
请参阅下面的我的用户和评论模型 .
class Comment < ActiveRecord::Base
belongs_to :post
belongs_to :user
default_scope { order('created_at DESC') }
validates :body, length: { minimum: 5 }, presence: true
after_create :send_favorite_emails
private
def send_favorite_emails
self.post.favorites.each do |favorite|
if favorite.user_id != self.user_id && favorite.user.email_favorites?
FavoriteMailer.new_comment(favorite.user, self.post, self).deliver
end
end
end
end
用户模型
class User < ActiveRecord::Base
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable, :confirmable
has_many :posts
has_many :comments
has_many :votes, dependent: :destroy
has_many :favorites, dependent: :destroy
mount_uploader :avatar, AvatarUploader
def role?(base_role)
role == base_role.to_s
end
def favorited(post)
self.favorites.where(post_id: post.id).first
end
def voted(post)
self.votes.where(post_id: post.id).first
end
private
end
2 回答
如果你得到了
它's that the thing you'重新调用你的方法是
nil.所以在你的情况下，你在零上调用
avatar?和name.看看你的代码，很明显
comment.user是（a）调用那些方法，因此（b）什么是零 .结果：您的评论没有用户 . 是强制执行所有注释（包括新/空/存根注释）以拥有用户（空白用户？），或者进行查看以便不需要用户 .
这个问题被发现了 . 在部分渲染中
应该