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.
Methods
Classes and Modules
Class ActionController::Flash::FlashHashPublic Class methods
[ show source ]
# File vendor/rails/actionpack/lib/action_controller/flash.rb, line 27
27: def self.included(base)
28: base.send :include, InstanceMethods
29:
30: base.class_eval do
31: alias_method :assign_shortcuts_without_flash, :assign_shortcuts
32: alias_method :assign_shortcuts, :assign_shortcuts_with_flash
33:
34: alias_method :process_cleanup_without_flash, :process_cleanup
35: alias_method :process_cleanup, :process_cleanup_with_flash
36: end
37: end