vendor/rails/railties/doc/guides/source/actioncontroller_basics/cookies.txt

   1 == Cookies ==
   2
   3 Your application can store small amounts of data on the client - called cookies - that will be persisted across requests and even sessions. Rails provides easy access to cookies via the `cookies` method, which - much like the `session` - works like a hash:
   4
   5 [source, ruby]
   6 -----------------------------------------
   7 class CommentsController < ApplicationController
   8
   9   def new
  10     #Auto-fill the commenter's name if it has been stored in a cookie
  11     @comment = Comment.new(:name => cookies[:commenter_name])
  12   end
  13
  14   def create
  15     @comment = Comment.new(params[:comment])
  16     if @comment.save
  17       flash[:notice] = "Thanks for your comment!"
  18       if params[:remember_name]
  19         # Remember the commenter's name
  20         cookies[:commenter_name] = @comment.name
  21       else
  22         # Don't remember, and delete the name if it has been remembered before
  23         cookies.delete(:commenter_name)
  24       end
  25       redirect_to @comment.article
  26     else
  27       render :action => "new"
  28     end
  29   end
  30
  31 end
  32 -----------------------------------------
  33
  34 Note that while for session values, you set the key to `nil`, to delete a cookie value, you should use `cookies.delete(:key)`.