module ZTK::DSL
# Generic Domain-specific Language Interface
#
# This module allows you to easily add attributes and relationships to classes
# to create a custom DSL in no time.
#
# You can then access these classes in manners similar to what *ActiveRecord*
# provides for relationships. You can easily link classes together; load
# stored objects from Ruby rb files (think Opscode Chef DSL).
#
# I intend the interface to act like ActiveRecord for the programmer and a
# nice DSL for the end user. It's not meant to be a database; more like
# a soft dataset in memory; extremely fast but highly volitale. As always
# you can never have your cake and eat it too.
#
# You specify the "schema" in the classes itself; there is no data storage at
# this time, but I do plan to add support for loading/saving *datasets* to
# disk. Keep in mind since you do not specify type constrants in Ruby, one
# can assign any object to an attribute.
#
# At this time if you do not specify an ID; one is auto generated.
#
# If you wish to create objects in a nested fashion the outer most object must
# be started using the class name initializer. Once inside the block you can
# start using the relationship names and do not need to call any further
# class initializers.
#
# You can also instantiate classes separately and associate them after the
# fact. That is not shown in this example.
#
# *example code*:
#
# class Network < ZTK::DSL::Base
# has_many :servers
#
# attribute :name
# attribute :gw
# attribute :network
# attribute :netmask
# end
#
# class Server < ZTK::DSL::Base
# belongs_to :network
#
# attribute :name
# end
#
# Network.new do
# id :leet_net
# name "leet-net"
# gw "7.3.3.1"
# network "7.3.3.0"
# netmask "255.255.255.0"
#
# server do
# name "leet-server"
# end
#
# server do
# id :my_server
# name "my-server"
# end
#
# server do
# name "dev-server"
# end
# end
#
# Network.count
# Network.all
# Network.find(:leet_net)
#
# Server.count
# Server.all
# Server.find(:my_server)
#
# *pry output*:
#
# [1] pry(main)> class Network < ZTK::DSL::Base
# [1] pry(main)* has_many :servers
# [1] pry(main)*
# [1] pry(main)* attribute :name
# [1] pry(main)* attribute :gw
# [1] pry(main)* attribute :network
# [1] pry(main)* attribute :netmask
# [1] pry(main)* end
# => #<Proc:0x0000000121f498@/home/zpatten/Dropbox/code/chef-repo/vendor/checkouts/ztk/lib/ztk/dsl/core/attributes.rb:45 (lambda)>
# [2] pry(main)> class Server < ZTK::DSL::Base
# [2] pry(main)* belongs_to :network
# [2] pry(main)*
# [2] pry(main)* attribute :name
# [2] pry(main)* end
# => #<Proc:0x00000001983108@/home/zpatten/Dropbox/code/chef-repo/vendor/checkouts/ztk/lib/ztk/dsl/core/attributes.rb:45 (lambda)>
# [3] pry(main)> Network.new do
# [3] pry(main)* id :leet_net
# [3] pry(main)* name "leet-net"
# [3] pry(main)* gw "7.3.3.1"
# [3] pry(main)* network "7.3.3.0"
# [3] pry(main)* netmask "255.255.255.0"
# [3] pry(main)*
# [3] pry(main)* server do
# [3] pry(main)* name "leet-server"
# [3] pry(main)* end
# [3] pry(main)*
# [3] pry(main)* server do
# [3] pry(main)* id :my_server
# [3] pry(main)* name "my-server"
# [3] pry(main)* end
# [3] pry(main)*
# [3] pry(main)* server do
# [3] pry(main)* name "dev-server"
# [3] pry(main)* end
# [3] pry(main)* end
# => #<Network id=:leet_net attributes={:id=>:leet_net, :name=>"leet-net", :gw=>"7.3.3.1", :network=>"7.3.3.0", :netmask=>"255.255.255.0"}, has_many_references=1>
# [4] pry(main)> Network.count
# => 1
# [5] pry(main)> Network.all
# => [#<Network id=:leet_net attributes={:id=>:leet_net, :name=>"leet-net", :gw=>"7.3.3.1", :network=>"7.3.3.0", :netmask=>"255.255.255.0"}, has_many_references=1>]
# [6] pry(main)> Network.find(:leet_net)
# => [#<Network id=:leet_net attributes={:id=>:leet_net, :name=>"leet-net", :gw=>"7.3.3.1", :network=>"7.3.3.0", :netmask=>"255.255.255.0"}, has_many_references=1>]
# [7] pry(main)> Server.count
# => 3
# [8] pry(main)> Server.all
# => [#<Server id=2 attributes={:id=>2, :name=>"leet-server", :network_id=>:leet_net}, belongs_to_references=1>,
# #<Server id=:my_server attributes={:id=>:my_server, :name=>"my-server", :network_id=>:leet_net}, belongs_to_references=1>,
# #<Server id=4 attributes={:id=>4, :name=>"dev-server", :network_id=>:leet_net}, belongs_to_references=1>]
# [9] pry(main)> Server.find(:my_server)
# => [#<Server id=:my_server attributes={:id=>:my_server, :name=>"my-server", :network_id=>:leet_net}, belongs_to_references=1>]
#
# @author Zachary Patten <zachary AT jovelabs DOT com>
class Base
include(ZTK::DSL::Core)
# @api private
def self.inherited(base)
base.send(:extend, ZTK::DSL::Base::ClassMethods)
base.instance_eval do
attribute :id
end
end
# @api private
def self.included(base)
# NOOP
end
# @api private
def self.extended(base)
# NOOP
end
def initialize(id=nil, &block)
self.id = (id || self.class.next_id)
self.class.dataset << self
block_given? and ((block.arity < 1) ? instance_eval(&block) : block.call(self))
primary_key_count = self.class.dataset.count do |d|
d.id == self.id
end
raise StandardError, "Primary key '#{self.id}' already exists!" if (primary_key_count > 1)
end
# Instance Inspect
#
# Inspect the DSL object's instance, returning a concise string
# representation of the instance.
#
# @return [String] A concise string representation of the instance.
def inspect
details = Array.new
details << "attributes=#{attributes.inspect}" if attributes.count > 0
details << "has_many_references=#{@has_many_references.count}" if @has_many_references
details << "belongs_to_references=#{@belongs_to_references.count}" if @belongs_to_references
"#<#{self.class.to_s} id=#{self.id.inspect} #{details.join(', ')}>"
end
# @author Zachary Patten <zachary AT jovelabs DOT com>
module ClassMethods
# Class Inspect
#
# Inspect the DSL object's class, returning a concise string
# representation of the class.
#
# @return [String] A concise string representation of the class.
def inspect
details = Array.new
details << "count=#{self.all.count}" if self.all.count > 0
"#<#{self.class.to_s}:#{self.id} #{details.join(', ')}>"
end
end
end
end