= BlockChainable

* http://block-chainable.rubyforge.org
* source - http://github.com/dfg59/block-chainable/tree/master

== DESCRIPTION:

BlockChainable is a module to aid in the creation of Domain Specific Languages using block structure.
By including BlockChainable into your classes, you will be able to instantiate that class using the
class name itself, followed by any parameters to be passed to initialize, followed by a block to be
executed within the instantiated class.

BlockChainable also allows methods to search up the chain of classes, meaning that although a block
is executed in the scope of the instantiated class, any methods not found in the class but found in a
class "up-scope" will be called successfully on the up-scope class. This chaining of method calls allows
you to assert values within the blocks as well as calling any other methods from "up-scope" classes.

== FEATURES/PROBLEMS:

* 2 major features
* Block instantiation of classes
* Method calls will look "up-scope" for receivers when called inside BlockChainable blocks
* 1 minor problem
* Stack trace should be simplified on errors within BlockChainable blocks

== SYNOPSIS:
# a simple nonsense example showing the ability to call methods in outer block scopes

# create some simple classes that include BlockChainable
require 'block_chainable'

class Foo
include BlockChainable

def hi_from_foo
puts "hello from foo"
end
end

class Bar
include BlockChainable

def hi_from_bar
puts "hello from bar"
end
end

class Boo
include BlockChainable

def hi_from_boo
puts "hello from boo"
end
end


# we can now use the classes in a DSL manner. notice that calls can happen from with blocks to
# "outer-block" methods.
Foo do
hi_from_foo

Bar do
hi_from_bar
hi_from_foo

Boo do
hi_from_boo
hi_from_bar
hi_from_foo
end
end
end

# A slighty more complicated example.
# a simple dsl for creating classroom rosters and printing them out. code can be found in the
# example directory.

require 'block_chainable'

# first, define our roster
class Roster
include BlockChainable

def initialize(subject)
@subject = subject
@students = []
end

def add_student_to_roster student
@students << student
end

def print_roster
puts "Roster for #@subject:"
@students.each{|s| puts " #{s}"}
end
end

# next, define our student. the only tricky part here is add_to_roster, which calls
# the method add_student_to_roster, which is actually defined on the Roster class.
# BlockChainable will automatically send this method to the Roster class with the
# Student instance as a parameter.
class Student
include BlockChainable

def add_to_roster
add_student_to_roster self
end

def to_s
"#@last_name, #@first_name - age #@age"
end

def first_name name
@first_name = name
end

def last_name name
@last_name = name
end

def age years
@age = years
end
end

# we now have all the pieces we need for creating a simple dsl for building
# and printing a class roster

Roster :Math do
Student do
first_name "Drew"
last_name "Olson"
age 25

add_to_roster
end

Student do
first_name "John"
last_name "Doe"
age 17

add_to_roster
end

Student do
first_name "Jane"
last_name "Doe"
age 19

add_to_roster
end

print_roster
end

== REQUIREMENTS:

* need
* rspec

== INSTALL:

* rubyforge - sudo gem install block-chainable
* github - sudo gem install dfg59-block-chainable --source=http://gems.github.com

== LICENSE:

(The MIT License)

Copyright (c) 2008 Drew Olson

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.