h2. What is StickyBlox?

StickyBlox is a late binding traits-approach to Ruby meta-programming. It allows you to define functionality within a class or object and apply that functionality to instances of other objects without having to know anything about how those other objects are created.

h2. Why?

If you're thinking to yourself, "I could just open a class and directly add the methods I want, and get the same behavior, or I could create a module and extend or include it where ever I want..." you would be right. So, why use StickyBlox? It's really a matter of taste. Sometimes, I don't like opening other classes to add my application specific behavior, and I would rather have somewhere else in which to encapsulate that behavior. I would also like to be able to reuse that behavior with any object without having to add the methods to every class in the system. StickyBlox allows you have the behavior shoe-horned into classes such that the functionalities (sticks) become instance methods or just have the stick available to be bound to anything, at anytime.

h2. Installing

What else?

[sudo] gem install sticky_blox

h2. Testing

The only dependency this library has is on RSpec during development and testing. To run tests

bundle check
bundle install # if dependencies are not satisfied
rake

h2. Example

With the later releases of Sinatra, your code is not reload-able in development. You either have to restart your server (which can be very burndensome, especially if you have a long start up time) or you have to run your application through some Shotgun or something similar.

Here we define a reloader for your route implementations. With this you can pull the logic or your routes out to well-defined components and then reload those components at run-time to get new behavior.

h3. app.rb

require 'reloading'

ReloadableRoutes.stick_to Sinatra::Application

get "/reload/:file/?" do
  reload
end

get "/touch_current_user/?" do
  touch_current_user
end

put "/run_as_someone_else/?" do
  # is the current user allowed to masquerade?
  current_user = session[:current_user]
  raise "unauthorized" unless current_user.allowed_to_masquerade_as_someone_else?

  # let's track the fact that our current user is masquerading
  touch_current_user

  # do some other marvelous stuff, but let's not argue about the use-cases of such a route

  # finally let's reset the application state for the current user
  session[:current_user] = current_user
end

['table1', 'table2'].each do |table_name|
  get table_name do
    load_records_for(table_name)
  end
end

h3. reloading.rb

require 'sticky_blox'

class ReloadableRoutes
  include StickyBlox

  stick :reload do
    # params comes from the instance of the Sinatra application into
    # which this stick is bound
    raise "no file specified" unless params[:file]
    load params[:file]
    "Success"
  end

  stick :touch_current_user do
    # use the instance variables typically available to an instance of a
    # Sinatra::Application, or subclass, to update some aspect of the system
    session[:current_user].touch
  end

  stick :load_records_for {|some_table_name|
    # again, params comes from the instance of the Sinatra application
    # into which this stick is bound
    model_for(some_table_name).filter(params[some_table_name]).all
  }
end