Module: ActionController::Flash

Defined in:
lib/action_controller/flash.rb

Overview

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 PostsController < ActionController::Base
  def create
    # save post
    flash[:notice] = "Successfully created post"
    redirect_to posts_path(@post)
  end

  def show
    # doesn't need to assign the flash notice to the template, that's done automatically
  end
end

show.html.erb
  <% 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.

Defined Under Namespace

Modules: InstanceMethods Classes: FlashHash, FlashNow

Class Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



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# File 'lib/action_controller/flash.rb', line 29

def self.included(base)
  base.class_eval do
    include InstanceMethods

    alias_method_chain :perform_action, :flash
    alias_method_chain :reset_session,  :flash
    alias_method_chain :redirect_to,    :flash

    helper_method :alert
    helper_method :notice
  end
end