Question

如何使用没有数据库表的模型验证表单（例如联系表单）（因此不是标准记录验证）。

我试过这个，但收到错误：undefined method有效吗？'联系方式：Class`

class Contact
  include ActiveModel::Validations
  attr_accessor :subject, :query
  validates :subject, { :presence => { message:'Please select a subject' } }
  validates :query, { :presence => { message:'Please enter your message' } }
  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end
  def persisted?
    false
  end
end

然后是方法：

def contact
  @page_title = 'Contact Us'
end

def contact_email
  if Contact.valid?
    message = "#{params[:subject]}: #{params[:query]}"
    current_user.send_contact_message(message)
    redirect_to '/contact', notice: 'Thank you for your message, we will be in touch shortly.'
  else
    render :contact
  end
end

Answer 1

valid?是一种实例方法。您只能在类的实例上调用它而不能在类上调用它。您需要更改此行

if Contact.valid?

到这个

contact = Contact.new(subject: 'some subject', query: 'some query')
if contact.valid?

希望有所帮助！

Answer 2

Rails 4的一个新功能是ActiveModel::Model，这使得创建无表格模型变得非常容易。它为您提供验证，通过I18n模块进行翻译，表单绑定，多态路由等。除了持久性之外，几乎所有ActiveRecord::Base都可以。

class Contact < ActiveModel::Model
  attr_accessor :subject, :query
  validates :subject, presence: { message:'Please select a subject' }
  validates :query, presence: { message:'Please enter your message' }
end

除此之外，您的错误是由于您在Contact类上调用.valid?而不是实例。

轨道方式是：

# config/routes.rb
resources :contacts, only: [:new, :create]

# app/controllers/contacts_controller.rb
class ContactsController < ApplicationController

  def new
    @contact = Contact.new
  end

  def create
    @contact = Contact.new(contact_params)
    if @contact.valid?
      message = "#{params[:subject]}: #{params[:query]}"
      current_user.send_contact_message(message)
      redirect_to '/contact', notice: 'Thank you for your message, we will be in touch shortly.'
    else
      render :new
    end
  end

  private 

    def contact_params
      params.require(:contact).permit(:foo, :bar)
    end
end

使用模型验证表单而不使用表

2 个答案: