attr_accessor可變零做before_validation回調

Question

當我做一個before_validation如下：

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 

和控制器的樣子：

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

起始日期是由設置a <％= f.text_field：start_date％>在窗體視圖中調用，當我檢查參數時，它正確地傳遞給模型控制器的'Create'方法，但是我如果build_start_time方法爲零，則不會設置self.start_time。你能解釋爲什麼它是零，解決方案是什麼？我也試過將它稱爲self.start_date，但這沒有什麼區別。

感謝

Answer 1

你有沒有試圖使start_date也可以訪問？

Answer 2

要麼你打電話attr_accessible與start_date所以build()實際上可以設置它，或者您可以將控制器更改爲：

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酒店沒有去銀行所以dados做código視頻= iX_rKHnKJSg = https://www.youtube.com/watch?v=iX_rKHnKJSg = iX_rKHnKJSg。

記錄在數據庫中，以便代碼iX_rKHnKJSg視頻=＃= https://www.youtube.com/watch?v=iX_rKHnKJSg iX_rKHnKJSg