Ruby on rails 为什么此代码返回一个“quot；作者中的命名错误“新”；错误？_Ruby On Rails

Ruby on rails 为什么此代码返回一个“quot；作者中的命名错误“新”；错误？

ruby-on-rails

Ruby on rails 为什么此代码返回一个“quot；作者中的命名错误“新”；错误？,ruby-on-rails,Ruby On Rails,下面是（身份验证部分），我在尝试访问localhost:3000/authors/new时遇到了这个错误 views/authors/_form.html.erb where line #2 raised: undefined method `errors' for nil:NilClass Extracted source (around line #2): <%= form_with(model: author, local: true) do |form| %&g

下面是（身份验证部分），我在尝试访问localhost:3000/authors/new时遇到了这个错误

    views/authors/_form.html.erb where line #2 raised:

    undefined method `errors' for nil:NilClass
Extracted source (around line #2):

<%= form_with(model: author, local: true) do |form| %>
  <% if author.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(author.errors.count, "error") %> prohibited this author from being saved:</h2>

      <ul>

解决方案是将before\u filter更改为before\u action，以防任何人也遇到这种情况。

您可能不会将

author

变量传递到

表单

部分。显示负责

表单

部分呈现的代码。

新作者

您是指authors/New.html.erb中的代码吗？好的，您做得很好，这里还有其他问题，我不确定现在是什么问题。在错误发生之前，日志会说什么？您确定要调用

new

操作吗？如果在\u filter之前出现错误，您能否从控制台或页面发布堆栈跟踪？在\u action之前使用

。你能给我们看看日志吗？是否zero\u authors\u或\u authenticated正在将用户重定向到索引操作，而您也在尝试在那里呈现表单？
class AuthorsController < ApplicationController
  before_action :set_author, only: [:show, :edit, :update, :destroy]
  before_filter :zero_authors_or_authenticated, only: [:new, :create]

  def zero_authors_or_authenticated
    unless Author.count == 0 || current_user
      redirect_to root_path
      return false
    end
  end

  # GET /authors
  # GET /authors.json
  def index
    @authors = Author.all
  end

  # GET /authors/1
  # GET /authors/1.json
  def show
  end

  # GET /authors/new
  def new
    @author = Author.new
  end

  # GET /authors/1/edit
  def edit
  end

  # POST /authors
  # POST /authors.json
  def create
    @author = Author.new(author_params)

    respond_to do |format|
      if @author.save
        format.html { redirect_to @author, notice: 'Author was successfully created.' }
        format.json { render :show, status: :created, location: @author }
      else
        format.html { render :new }
        format.json { render json: @author.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /authors/1
  # PATCH/PUT /authors/1.json
  def update
    respond_to do |format|
      if @author.update(author_params)
        format.html { redirect_to @author, notice: 'Author was successfully updated.' }
        format.json { render :show, status: :ok, location: @author }
      else
        format.html { render :edit }
        format.json { render json: @author.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /authors/1
  # DELETE /authors/1.json
  def destroy
    @author.destroy
    respond_to do |format|
      format.html { redirect_to authors_url, notice: 'Author was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_author
      @author = Author.find(params[:id])
    end

    # Only allow a list of trusted parameters through.
    def author_params
      params.require(:author).permit(:username, :email, :password, :password_confirmation)
    end




end


<%= form_with(model: author, local: true) do |form| %>
  <% if author.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(author.errors.count, "error") %> prohibited this author from being saved:</h2>

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

  <div class="field">
    <%= form.label :username %>
    <%= form.text_field :username %>
  </div>

  <div class="field">
    <%= form.label :email %>
    <%= form.text_field :email %>
  </div>

  <div class="field">
    <%= form.label :password %>
    <%= form.text_field :password %>
  </div>

  <div class="field">
    <%= form.label :password_confirmation %>
    <%= form.text_field :password_confirmation %>
  </div>

  <div class="actions">
    <%= form.submit %>
  </div>
<% end %>


    <h1>New Author</h1>

    <%= render 'form', author: @author %>

    <%= link_to 'Back', authors_path %>


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