flash.now[:error] = ""

render :new

flash[:error] = ""

redirect videos_path

http://guides.rubyonrails.org/action_controller_overview.html

The flash is a special part of the session which is cleared with each request. This means that values stored there will only be available in the next request, which is useful for passing error messages etc.

It is accessed in much the same way as the session, as a hash (it's a FlashHash instance).

Let's use the act of logging out as an example. The controller can send a message which will be displayed to the user on the next request:

class LoginsController < ApplicationController

  def destroy

    session[:current_user_id] = nil

    flash[:notice] = "You have successfully logged out."

    redirect_to root_url

  end

end

Note that it is also possible to assign a flash message as part of the redirection.

You can assign :notice, :alert or the general purpose :flash:

redirect_to root_url, notice: "You have successfully logged out."

redirect_to root_url, alert: "You're stuck here!"

redirect_to root_url, flash: { referral_code: 1234 }

The destroy action redirects to the application's root_url, where the message will be displayed. Note that it's entirely up to the next action to decide what, if anything, it will do with what the previous action put in the flash. It's conventional to display any error alerts or notices from the flash in the application's layout:

<html>

  <!-- <head/> -->

  <body>

    <% flash.each do |name, msg| -%>

      <%= content_tag :div, msg, class: name %>

    <% end -%>

 

    <!-- more content -->

  </body>

</html>

This way, if an action sets a notice or an alert message, the layout will display it automatically.

You can pass anything that the session can store; you're not limited to notices and alerts:

<% if flash[:just_signed_up] %>

  <p class="welcome">Welcome to our site!</p>

<% end %>

If you want a flash value to be carried over to another request, use the keep method:

class MainController < ApplicationController

  # Let's say this action corresponds to root_url, but you want

  # all requests here to be redirected to UsersController#index.

  # If an action sets the flash and redirects here, the values

  # would normally be lost when another redirect happens, but you

  # can use 'keep' to make it persist for another request.

  def index

    # Will persist all flash values.

    flash.keep

 

    # You can also use a key to keep only some kind of value.

    # flash.keep(:notice)

    redirect_to users_url

  end

end
5.2.1 flash.now

By default, adding values to the flash will make them available to the next request, but sometimes you may want to access those values in the same request.

For example, if the create action fails to save a resource and you render the new template directly,

that's not going to result in a new request, but you may still want to display a message using the flash.

To do this, you can use flash.now in the same way you use the normal flash:

class ClientsController < ApplicationController

  def create

    @client = Client.new(params[:client])

    if @client.save

      # ...

    else

      flash.now[:error] = "Could not save client"

      render action: "new"

    end

  end

end

The Flash的更多相关文章

  1. 隐私泄露杀手锏 —— Flash 权限反射

    [简版:http://weibo.com/p/1001603881940380956046] 前言 一直以为该风险早已被重视,但最近无意中发现,仍有不少网站存在该缺陷,其中不乏一些常用的邮箱.社交网站 ...

  2. 百度 flash html5自切换 多文件异步上传控件webuploader基本用法

    双核浏览器下在chrome内核中使用uploadify总有302问题,也不知道如何修复,之所以喜欢360浏览器是因为帮客户控制渲染内核: 若页面需默认用极速核,增加标签:<meta name=& ...

  3. 解决“chrome提示adobe flash player 已经过期”的小问题

    这个小问题也确实困扰我许久,后来看到chrome吧里面有人给出了解决方案: 安装install_flash_player_ppapi, 该软件下载地址:http://labs.adobe.com/do ...

  4. 在 Linux 中使用搜狗拼音输入法以及搞定 Flash 和支付宝

    在 Ubuntu 中安装搜狗输入法 在 Ubuntu Kylin 系统中,默认安装搜狗拼音输入法,但是在原生 Ubuntu 系统中则不是.这可以理解,毕竟搜狗输入法的 Linux 版有 Kylin 团 ...

  5. [异常解决] ubuntukylin16.04 LTS中关于flash安装和使用不了的问题解决

    http://www.linuxdiyf.com/linux/25211.html 归纳解决flash插件大法: 启动器中找到 软件更新,启动,点击 其它软件,把Canonical合作伙伴前方框 选上 ...

  6. 基于Adobe Flash平台的3D页游技术剖析

    写在前面 从黑暗之光,佛本是道,大战神的有插件3D页游.再到如今的魔龙之戒. 足以证明,3D无插件正在引领页游技术的潮流. 目前,要做到3D引擎,有以下几个选择. 说到这里,我们发现.这些都不重要. ...

  7. 强大的flash头像上传插件(支持旋转、拖拽、剪裁、生成缩略图等)

    今天介绍的这款flash上传头像功能非常强大,支持php,asp,jsp,asp.net 调用 头像剪裁,预览组件插件. 本组件需要安装Flash Player后才可使用,请从http://dl.pc ...

  8. MDK st-link下载STM32程序出现Internal command error和Error:Flash download failed. Target DLL

    MDK st-link下载STM32程序出现Internal command error和Error:Flash download failed. Target DLL   是因为目标板的芯片处于休眠 ...

  9. 嵌入式Linux驱动学习之路(二十四)Nor Flash驱动程序

    Nor Flash和Nand Flash的不同: 类型 NOR Flash  Nand Flash  接口 RAM-like,引脚多 引脚少 容量 小(1M.2M...) 大(512M.1G) 读 简 ...

  10. mtk flash tool，Win7 On VirtualBox

    SP_Flash_Tool_exe_Windows_v5.1624.00.000 Win7 在 VirtualBox, 安裝 mtk flash tool, v5.1628 在燒錄時會 fail. v ...

随机推荐

  1. gulp初体验记录(简介、插件开发介绍)

    目前用的业界比较知名的三个前端构建工具:grunt.gulp.fis,自己此前一直都是只在用grunt,fis看过一点,gulp则一直都没注意过,直到最近发现好像用的人越来越多,所以今天也就抽了点时间 ...

  2. Mac 下安装tomcat

    一. 下载tomcat 首先要到tomcat官网去下载安装包,官网下载地址如下:http://tomcat.apache.org/download-70.cgi , 注意请下载飞windows版本.和 ...

  3. Shadowsock搭建

    搭建Shadowsocks服务端: 搭建Shadowsocks之前首先必须购买一个VPS.一般VPS提供商会给一个测试地址,购买之前最好先ping一下速度.也可以通过以下网址测试下vps网络速度: h ...

  4. [BZOJ1089][SCOI2003]严格n元树(递推+高精度)

    题目:http://www.lydsy.com:808/JudgeOnline/problem.php?id=1089 分析: 第一感觉可以用一个通式求出来,但是考虑一下很麻烦,不好搞的.很容易发现最 ...

  5. 标准I/O

    在程序运行时,会默认为我们打开三个流:标准输入流.标准输出流.标准出错流. 标准输入流一般对应我们的键盘 标准输出流一般对应显示器 标准出错流一般也对应显示器 1.标准输入流 在标准I/O中,java ...

  6. array，vertor，arraylist，hashable，hashmap等几个易混淆概念的区别

    Array可以存放Object和基本数据类型,但创建时必须指定数组的大小,并不能再改变, Vertor是放的Object. Vertor一维,Hashmap/Hashtabe二维: Vertor/Ar ...

  7. 【poj1009】 Edge Detection

    http://poj.org/problem?id=1009 (题目链接) 不得不说,poj上的水题还是质量非常高的= =,竟然让本大爷写了一下午. 转自:http://blog.sina.com.c ...

  8. Web Api如何传递POST请求

    这里记录一次Web Api传递post请求的例子,由于使用了默认工程的例子,方法名的参数值标记头为FromBody的形式,如下图所示的调用: 调用方式: 那么如果要两个以上的参数如何去实现,这种方式是 ...

  9. 5种风格的 jQuery 分页效果【附代码】

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xht ...

  10. Java及Android开发环境搭建

    前言 自从接触java以来,配置环境变量折腾了好几次,也几次被搞得晕头转向,后来常常是上网查阅相关资料才解决.但是过一段时间后一些细节就会记不清了,当要在其他机子上配置时又得上网查或者查阅相关书籍,如 ...