== Cookies ==

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:

[source, ruby]
-----------------------------------------
class CommentsController < ApplicationController

  def new
    #Auto-fill the commenter's name if it has been stored in a cookie
    @comment = Comment.new(:name => cookies[:commenter_name])
  end

  def create
    @comment = Comment.new(params[:comment])
    if @comment.save
      flash[:notice] = "Thanks for your comment!"
      if params[:remember_name]
        # Remember the commenter's name
        cookies[:commenter_name] = @comment.name
      else
        # Don't remember, and delete the name if it has been remembered before
        cookies.delete(:commenter_name)
      end
      redirect_to @comment.article
    else
      render :action => "new"
    end
  end

end
-----------------------------------------

Note that while for session values, you set the key to `nil`, to delete a cookie value, you should use `cookies.delete(:key)`.