surveillance_authority

Introduction

This gem provides a dsl to easily write observers in one or more centralized files.

Installation

Install surveillance_authority by adding

gem 'surveillance_authority'

to your Gemfile or install it using

gem install surveillance_authority

Integration into your project

config/initializers

create one or more ruby files in which you can define your surveillance rules. For example:

SurveillanceAuthority.observe do
  # Do something after a new movie was created
  after "Movie#create" do |movie|
     # ... do stuff
  end

  # Do something before a User gets updated
  before "User#update" do |user|
    # ... do stuff
  end
end

Uhm …so what?

surveillance_authority is meant to be used together with some plugins. One of those is varnish_sweeper, which invalidates certain routes.

Writing plugins for surveillance_authority

In order to write a plugin for surveillance_authority, simply create a class that inherits from

SurveillanceAuthority::Sanctions

all public methods of that class will be available in the blocks. E.g.

class VarnishSweeper < SurveillanceAuthority::Sanctions
  def sweep(url, options = {})
    options.reverse_merge(
      :method => :invalidate
    }

    options[:method] == :purge ? purge_url(url) : invalidate(url)
  end

  private
  def purge_url(url)
    ...
  end

  def invalidate(url)
    ...
  end
end

will make the sweep method available: