Class: ActionDispatch::Flash
Relationships & Source Files | |
Namespace Children | |
Modules:
| |
Classes:
| |
Inherits: | Object |
Defined in: | actionpack/lib/action_dispatch/middleware/flash.rb |
Overview
The flash provides a way to pass temporary primitive-types (String, ::Array
, ::Hash
) 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] = "Post successfully created"
before redirecting to a display action that can then expose the flash to its template. Actually, that exposure is automatically done.
class PostsController < ActionController::Base
def create
# save post
flash[:notice] = "Post successfully created"
redirect_to @post
end
def show
# doesn't need to assign the flash notice to the template, that's done automatically
end
end
Then in show.html.erb
:
<% if flash[:notice] %>
<div class="notice"><%= flash[:notice] %></div>
<% end %>
Since the notice
and alert
keys are a common idiom, convenience accessors are available:
flash.alert = "You must be logged in"
flash.notice = "Post successfully created"
This example places a string in the flash. And of course, you can put as many as you like at a time too. If you want to pass non-primitive types, you will have to handle that in your application. Example: To show messages with links, you will have to use sanitize helper.
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.
Constant Summary
-
KEY =
# File 'actionpack/lib/action_dispatch/middleware/flash.rb', line 44"action_dispatch.request.flash_hash"
Class Method Summary
- .new(app) ⇒ Flash constructor
Constructor Details
.new(app) ⇒ Flash
# File 'actionpack/lib/action_dispatch/middleware/flash.rb', line 300
def self.new(app) app; end