Ajax flash message in ruby on rails

问题

I'm trying to show a flash message and render it with Ajax, but the message does not seem to be appearing until after I refresh the page.

Here's my create.rjs file:

page.insert_html :top, :feed_items, :partial => 'shared/feed_item', :object => @micropost
page.replace_html :user_info, pluralize(current_user.microposts.count, "micropost")
page[:micropost_form].reset
page.replace_html :notice, flash[:notice]
flash.discard

Here's the relevant part of my application layout view:

<div id= "notice"><% flash.each do |key, value| %>
   <div class="flash <%= key %>"><%= value %></div>
<% end %></div>

And here's the relevant part of my micropost controller:

class MicropostsController < ApplicationController
  before_filter :authenticate, :only => [:create, :destroy]
  before_filter :authorized_user, :only => :destroy

  def create
    @micropost  = current_user.microposts.build(params[:micropost])
    respond_to do |format|
      if @micropost.save
        flash[:success] = "Micropost created!"

        format.html { redirect_to root_path }
        format.js   
      else
        @feed_items = []
        render 'pages/home'
      end  
    end
  end

So why isn't the flash message showing up right away?

回答1:

Flash messages by design are stored in the session until the next page load. In the case of ajax, don't use flash. For one thing, the div to replace the message into may not exist, so you need to add that to your page as a container to add to. Second, just do it from a regular variable, not flash.

A regular variable would be:

@message = "Micropost created!"

instead of the flash[:success]

The js view would use this variable instead of flash.

回答2:

Instead of page.replace_html :notice, flash[:notice]
Try this page.replace_html :notice, "Some info to flash"

来源：https://stackoverflow.com/questions/5187965/ajax-flash-message-in-ruby-on-rails