Micro Sessions

DEPRECATION WARNING: micro_session 0.4.0 includes breaking changes, for previous versions see Readme.

In terms of passing data amongst HTTP requests there are really two options:

• Param or form data passing
• Storing in cookies
• Storing in server-side session, keyed off an ID stored as a cookie.

For a certain application where you're using number 3, this comes at a cost - the session is "global". In other words, in a single browser window with multiple tabs, the server side cannot distinguish between individual "sessions" within that browser session. This gem introduces a fourth, more granular method:

• Storing in server-side session, keyed off an ID stored as a cookie and keyed off a request parameter.

This could be useful in instances such as a very complex wizard where transmitting the entire history of data RESTfully via param passing may not be feasible, yet you'd still like to support multiple tabs within the same browser window separately.

Include the gem in your Gemfile:

gem "micro_sessions"

Simply include MicroSessionable in your controller:

class ApplicationController
  include MicroSessionable
end

From there you will have access to a micro_session object in your controllers and views, just like the session object.

def new
  micro_session[:key] = "Value"
end

By default the name of the request parameter used to differentiate micro-sessions is _msid, though this can be configured:

MicroSession.configure do |config|
  config.key = "_msid"
end

By default the key generated will be a 10-digit random hash, though this can be configured as well:

MicroSession.configure do |config|
  config.type = :integer
  config.length = 10
end

Valid values for type are:

• :random_hash
• :integer (simply increments from one)
• :random_integer (random integer with a maximum of :length digits)

Session data is accessible to the controller and view through the micro_session object, which works identically to the session object but it specific to the micro-session:

micro_session[:key] = "Value"
micro_session[:key] # => "Value"

When transitioning between pages for which you'd like to keep the micro-session alive, just use the custom ms_link_to helper method:

ms_link_to "Persist session", user_path(@user)

You can also build the url manually getting the proper information from micro_session:

redirect_to user_path(@user, micro_session.url_options)

If you wish to transmit the identifier via a form, be sure to include the hidden field:

<% form_for(@user) do |f| %>
  <%= micro_session_hidden_field %>
  ...
<% end %>