Question

我正在尝试使用this tutorial为我的Rails 3.1.3应用程序添加联系表单。但是当我尝试加载我的联系页面时，我收到错误：

当你没想到它时，你有一个零对象！您可能期望一个Array实例。在评估nil。[]

时发生错误

它表示它出现在new.html.haml页面上此代码块的第1行：

  = form_for @message, :url => { :action=>"new", :controller=>"contact"} do |form|
    %fieldset.fields
      .field
        = form.label :name
        = form.text_field :name
      .field
        = form.label :email
        = form.text_field :email
      .field
        = form.label :body
        = form.text_area :body
    %fieldset.actions
      = form.submit "Send"

我的控制器看起来像这样：

class ContactController < ApplicationController
    def new
        @message = Message.new
    end

  def create
    @message = Message.new(params[:message])

    if @message.valid?
      NotificationsMailer.new_message(@message).deliver
      redirect_to(root_path, :notice => "Message was successfully sent.")
    else
      flash.now.alert = "Please fill all fields."
      render :new
    end
  end
end

模型看起来像这样：

class Message < ActiveRecord::Base
  include ActiveModel::Validations
  include ActiveModel::Conversion
  extend ActiveModel::Naming

  attr_accessor :name, :email, :body

  validates :name, :email, :body, :presence => true
  validates :email, :format => { :with => %r{.+@.+\..+} }, :allow_blank => true

  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end

  def persisted?
    false
  end

end

为什么我会收到该错误，如何解决？谢谢！

Answer 1

你是否在教程中添加了路由？

match 'contact' => 'contact#new', :as => 'contact', :via => :get
match 'contact' => 'contact#create', :as => 'contact', :via => :post

除了你可以在你的形式使用

<%= form_for @message, :url => contact_path do |form| %>

Answer 2

如果您使用单独的表单进行新操作和编辑操作，可以在new.html.haml

中使用

 = form_for :message, :url => { :action=>"new", :controller=>"contact"} do |form|

或

= form_for :message, @message, :url => { :action=>"new", :controller=>"contact"} do |form|

Nil对象，当你没有想到它的联系form_for

2 个答案: