ruby-on-rails - Rails Flash 消息未显示

Question

我在 Controller 中有一行将重定向到带有自定义 flash 消息的主屏幕，如下所示:

redirect_to :controller => :home, :action => :index, :alert => "You are not yet assigned to an experiment." and return

然后用户被重定向到以下页面:http://localhost:3000/home?alert=You+are+not+yet+assigned+to+an+experiment

但是，虽然所有其他的闪现消息在我的应用程序中都有效，但闪现消息并没有显示出来。 views/layouts/application.html.erb 文件包含以下内容:

<div class="flash">
    <%- if !notice.nil? -%>
    <p class="notice"><%= notice %></p>
    <%- end -%> 
    <%- if !alert.nil? -%>
    <p class="alert"><%= alert %></p>
    <%- end -%>     
</div>

我在这里做错了什么？

Answer 1

Flash 正在使用 session 来存储消息

flash[:alert] = "You are not yet assigned to an experiment."
redirect_to :controller => :home, :action => :index and return
<%= flash[:alert] %>

如果你想通过 params 传递它，你应该使用 params[:param_name]

redirect_to :controller => :home, :action => :index, :alert => "You are not yet assigned to an experiment." and return
<%= params[:alert] %>

Flash更可取，它隐含地跨页面工作，显示后被清除