Question

我正在执行before_validation，如下所示：

event.rb

attr_accessor :start_date
attr_accessible :start_time #recorded in database as a datetime

before_validation :build_start_time

...

def build_start_time
  begin
    self.start_time = DateTime.parse(start_date)
  rescue
      errors.add(:start_date, "invalid date")
      return false
  end
end

并且控制器看起来像：

def create
  @event = events.build(params[:event])
  if @event.save
    # some other method calls
    redirect_to @event
  else
    redirect_to :root
  end
end

start_date由＆lt;％= f.text_field：start_date％＆gt;设置在窗体视图中调用，当我检查params时，它正确地传递给模型控制器的'Create'方法，但是在build_start_time方法中它是nil，因此没有设置self.start_time。你能解释为什么它会是零，解决方案是什么？我也尝试将其称为self.start_date，但这没有什么区别。

由于

Answer 1

您是否尝试过start_date也可以访问？

Answer 2

您可以使用attr_accessible致电start_date，以便build()可以实际设置它，或者您可以将控制器更改为：

def create
  @event = events.build(params[:event])
  @event.start_date = params[:event][:start_date]
  if @event.save
    # some other method calls
    redirect_to @event
  else
    redirect_to :root
  end
end

Answer 3

tente assim。

#app/models/adm/video.rb
class Adm::Video < ActiveRecord::Base
  validates :titulo, :url_codigo, presence: true
  before_validation(on: [ :create, :update ]) do
    self.url_codigo = parse_youtube(url_codigo) #url_codigo = params[:adm_video][:url_codigo]
  end

  private
  #  pega só o codigo do link youtube para inserir no banco 
  def parse_youtube(url)
   if !url.blank?
     regex = /(?:.be\/|\/watch\?v=|\/(?=p\/))([\w\/\-]+)/
     return url.match(regex)[1] # https://www.youtube.com/watch?v=iX_rKHnKJSg = iX_rKHnKJSg
   end
 end

end

grava no banco dedadossócódigodovideo = iX_rKHnKJSg = https://www.youtube.com/watch?v=iX_rKHnKJSg = iX_rKHnKJSg。

数据库中的记录sò代码iX_rKHnKJSg video =＃= https://www.youtube.com/watch?v=iX_rKHnKJSg iX_rKHnKJSg

执行before_validation回调时attr_accessor变量为nil

3 个答案: