Module | ActionController::Flash |
In: |
vendor/rails/actionpack/lib/action_controller/flash.rb
|
The flash provides a way to pass temporary objects between actions. Anything you place in the flash will be exposed to the very next action and then cleared out. This is a great way of doing notices and alerts, such as a create action that sets flash["notice"] = "Successfully created" before redirecting to a display action that can then expose the flash to its template. Actually, that exposure is automatically done. Example:
class WeblogController < ActionController::Base def create # save post flash["notice"] = "Successfully created post" redirect_to :action => "display", :params => { "id" => post.id } end def display # doesn't need to assign the flash notice to the template, that's done automatically end end display.rhtml <% if @flash["notice"] %><div class="notice"><%= @flash["notice"] %></div><% end %>
This example just places a string in the flash, but you can put any object in there. And of course, you can put as many as you like at a time too. Just remember: They‘ll be gone by the time the next action has been performed.
See docs on the FlashHash class for more details about the flash.
Access the contents of the flash. Use flash["notice"] to read a notice you put there or flash["notice"] = "hello" to put a new one.
# File vendor/rails/actionpack/lib/action_controller/flash.rb, line 132 132: def flash #:doc: 133: @session['flash'] ||= FlashHash.new 134: end