kemal-session

This project wants to be a session plugin for Kemal when it grows up. Right now it is still kind of crude and I wouldn't recommend anyone using it... but it works! ;-)

Installation

Add this to your application's shard.yml:

dependencies:
  kemal-session:
    github: Thyra/kemal-session
    branch: master

Usage

Basic Usage

Create a folder sessions in the same directory that your webserver is running in and make sure the webserver process has write privileges to it.

require "kemal"
require "kemal-session"

get "/set" do |env|
  session = Session.start(env)
  session.int["number"] = rand(100)
  session.save
end

get "/get" do |env|
  session = Session.start(env)
  session.int["number"]
end

The session can save Int32, String, Float64 and Bool values. Use session.int, session.string, session.float and session.bool for that, they are all Hashes with String keys. Whenever you change something in the session call session.save at the end of the block so that your changes are saved (I know this is horrible and I promise it won't stay like that).

Another example

require "kemal"
require "kemal-session"

get "/rand" do |env|
  session = Session.start(env)
  if session.int.has_key? "random_number"
    env.response.print "The last random number was #{session.int["random_number"]}. "
  else
    env.response.print "This is the first random number. "
  end
  random_number = rand(500)
  env.response.print "Setting the random number to #{random_number}"
  session.int["random_number"] = random_number
  session.save
end

get "/set" do |env|
  session = Session.start(env)
  session.string[env.params["key"].to_s] = env.params["value"].to_s
  session.save
end

get "/get" do |env|
  session = Session.start(env)
  if session.string.has_key? env.params["key"].to_s
    "The value of #{env.params["key"]} is #{session.string[env.params["key"].to_s]}"
  else
    "There is no value for this key."
  end
end

get "/view" do |env|
  session = Session.start(env)
  env.response.content_type = "application/json"
  session.to_json
end

Open /set?key=foo&value=bar to set the value of foo to bar in your session. Then open /get?key=foo to retrieve it.

Configuration

The Session can be configured in the same way as Kemal itself:

Session.config do |config|
  config.cookie_name = "session_id"
  config.gc_interval = Time::Span.new(0, 1, 0)
end

Session.config.cookie_name = "foobar"

Option	explanation	default
timeout	How long is the session valid after last user interaction?	`Time::Span.new(1, 0, 0)` (1 hour)
cookie_name	Name of the cookie that holds the session_id on the client	`"kemal_sessid"`
engine	How are the sessions saved on the server? (so far only `filesystem` is available)	`"filesystem"`
sessions_dir	For filesystem engine: in which directory are the sessions saved?	`"./sessions/"`
gc_interval	In which interval should the garbage collector find and delete expired sessions from the server?	`Time::Span.new(0, 4, 0)` (4 minutes)

Features already implemented

storing of Int32, String, Float64 and Bool values
a garbage collector that removes expired sessions from the server
a filesystem engine (saves sessions on the file system)

Features in development

a smart way of automatic saving...
storing of more data types, including arrays and possibly hashes
engines for memory (sessions are stored in process memory), mysql and postregsql (sessions are stored in database)
secure session id against brute force attacks by binding it to ip adress and user agent