Atomics Resource¶ ↑

Ruby and/or Rails interface for Atomics queries. Atomics is MySQL over HTTP, originally developed at CNET and has similar intent to DBSlayer (see MySQL in an Enterprise Search Architecture).

This module use a different approach from e.g. activerecord-dbslayer-adapter, which subclasses the MySQL adapter in order to use ActiveRecord. Rather, AtomicsResource is a lightweight re-implementation of some ActiveRecord-style methods, which means the module can be used in non-Rails apps, or mixed with non-MySQL connections in a Rails app.

Classes representing resources in atomics are created by subclassing AtomicsResource::Base. Class find methods are mapped to HTTP GET requests. XML responses are parsed and mapped to an instance of the class.

Rails is not required, atomics_resource may be used in any Ruby code. However, if RAILS_ROOT is defined, the module will extend ActiveModel::Naming, which provides polymorphics paths for use in views.

To use an instance, you will need to create a yaml file with atomics configs, e.g. config/atomics.yml:

hr:
  host: hr-atomics.newco.com
  port: 8080
  path: /jAtomics/select/?version=1

then load the file into a hash called ATOMICS_CONFIG; in Rails this is best done from an initializer, e.g. config/initializers/atomics_config.rb:

ATOMICS_CONFIG = YAML.load_file("#{RAILS_ROOT}/config/atomics.yml")

Your model will look like this:

class Employee < AtomicsResource::Base
  set_atomics_type :hr                #section of config file to read
  set_table_name   :employee_display  #default table for requests
  set_primary_key  :id                #default key for find() methods

  ## default columns to SELECT, if none-given default will be '*'
  column :first_name
  column :last_name
  column :title
  column :team_id
end

and a simple controller:

class EmployeesController < ApplicationController
  def index
    @employees = Employee.all(:conditions => [ "team_id = ?", params[:team] ]
                              :order      => [ :last_name, :first_name ])
  end

  def show
    @employee = Employee.find(params[:id])
  end
end

Conditions may be given as follows:

:conditions => "team_id = 156 AND title = 'Manager'"
:conditions => [ "team_id = ? AND title = ?", 156, 'Manager' ]
:conditions => [ "team_id = %d AND title = %s", 156 , 'Manager' ]
:conditions => { :team_id => 156, :title => :Manager }

Columns: in general you don’t want to do “SELECT *” from Atomics tables, which are frequently huge, denormalized beasts which will put a lot of extra data on the wire that you don’t want. Instead, list in the model the columns you normally want, using ‘column’. These will be used to create the default ‘SELECT’ statement in find(). This can be overridden using something like find(:all, :select=>‘*’).

Convenience functions:

Employee.all(99)     ## equivalent to Employee.find(:all,   :conditions => {:id = 99})
Employee.first(99)   ## equivalent to Employee.find(:first, :conditions => {:id = 99})
Employee.last(99)    ## equivalent to Employee.find(:last,  :conditions => {:id = 99})

The project is available for forking at github: github.com/rlister/atomics_resource. Please contribute any bugfixes or improvements.

Copyright © 2011 Richard Lister. See LICENSE.txt for further details.