--- /dev/null
+module ActionController #:nodoc:
+ # 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 <tt>flash[:notice] = "Successfully created"</tt> 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.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.
+ module Flash
+ def self.included(base)
+ base.class_eval do
+ include InstanceMethods
+ alias_method_chain :assign_shortcuts, :flash
+ alias_method_chain :reset_session, :flash
+ end
+ end
+
+
+ class FlashNow #:nodoc:
+ def initialize(flash)
+ @flash = flash
+ end
+
+ def []=(k, v)
+ @flash[k] = v
+ @flash.discard(k)
+ v
+ end
+
+ def [](k)
+ @flash[k]
+ end
+ end
+
+ class FlashHash < Hash
+ def initialize #:nodoc:
+ super
+ @used = {}
+ end
+
+ def []=(k, v) #:nodoc:
+ keep(k)
+ super
+ end
+
+ def update(h) #:nodoc:
+ h.keys.each { |k| keep(k) }
+ super
+ end
+
+ alias :merge! :update
+
+ def replace(h) #:nodoc:
+ @used = {}
+ super
+ end
+
+ # Sets a flash that will not be available to the next action, only to the current.
+ #
+ # flash.now[:message] = "Hello current action"
+ #
+ # This method enables you to use the flash as a central messaging system in your app.
+ # When you need to pass an object to the next action, you use the standard flash assign (<tt>[]=</tt>).
+ # When you need to pass an object to the current action, you use <tt>now</tt>, and your object will
+ # vanish when the current action is done.
+ #
+ # Entries set via <tt>now</tt> are accessed the same way as standard entries: <tt>flash['my-key']</tt>.
+ def now
+ FlashNow.new(self)
+ end
+
+ # Keeps either the entire current flash or a specific flash entry available for the next action:
+ #
+ # flash.keep # keeps the entire flash
+ # flash.keep(:notice) # keeps only the "notice" entry, the rest of the flash is discarded
+ def keep(k = nil)
+ use(k, false)
+ end
+
+ # Marks the entire flash or a single flash entry to be discarded by the end of the current action:
+ #
+ # flash.discard # discard the entire flash at the end of the current action
+ # flash.discard(:warning) # discard only the "warning" entry at the end of the current action
+ def discard(k = nil)
+ use(k)
+ end
+
+ # Mark for removal entries that were kept, and delete unkept ones.
+ #
+ # This method is called automatically by filters, so you generally don't need to care about it.
+ def sweep #:nodoc:
+ keys.each do |k|
+ unless @used[k]
+ use(k)
+ else
+ delete(k)
+ @used.delete(k)
+ end
+ end
+
+ # clean up after keys that could have been left over by calling reject! or shift on the flash
+ (@used.keys - keys).each{ |k| @used.delete(k) }
+ end
+
+ private
+ # Used internally by the <tt>keep</tt> and <tt>discard</tt> methods
+ # use() # marks the entire flash as used
+ # use('msg') # marks the "msg" entry as used
+ # use(nil, false) # marks the entire flash as unused (keeps it around for one more action)
+ # use('msg', false) # marks the "msg" entry as unused (keeps it around for one more action)
+ def use(k=nil, v=true)
+ unless k.nil?
+ @used[k] = v
+ else
+ keys.each{ |key| use(key, v) }
+ end
+ end
+ end
+
+ module InstanceMethods #:nodoc:
+ protected
+ def reset_session_with_flash
+ reset_session_without_flash
+ remove_instance_variable(:@_flash)
+ flash(:refresh)
+ end
+
+ # Access the contents of the flash. Use <tt>flash["notice"]</tt> to read a notice you put there or
+ # <tt>flash["notice"] = "hello"</tt> to put a new one.
+ # Note that if sessions are disabled only flash.now will work.
+ def flash(refresh = false) #:doc:
+ if !defined?(@_flash) || refresh
+ @_flash =
+ if session.is_a?(Hash)
+ # don't put flash in session if disabled
+ FlashHash.new
+ else
+ # otherwise, session is a CGI::Session or a TestSession
+ # so make sure it gets retrieved from/saved to session storage after request processing
+ session["flash"] ||= FlashHash.new
+ end
+ end
+
+ @_flash
+ end
+
+ private
+ def assign_shortcuts_with_flash(request, response) #:nodoc:
+ assign_shortcuts_without_flash(request, response)
+ flash(:refresh)
+ flash.sweep if @_session && !component_request?
+ end
+ end
+ end
+end
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