zm69 · March 20, 2018 20:08 · Mar 20, 2018 · Jan 2, 2015 · Jan 2, 2015 · Jan 2, 2015
diff --git a/dci_example.rb b/dci_example.rb
@@ -1,4 +1,5 @@
 # DCI EXAMPLE IN RUBY (with some prototype elements)
+# Blog post: https://www.ludyna.com/oleh/dci-example-in-ruby
 # 
 # More info: 
 #

diff --git a/dci_example.rb b/dci_example.rb
@@ -53,7 +53,8 @@ def do_parenting(parent, child)
 
 
 # (proposal #2) New Ruby keyword "as". This keyword _temporary_ extends modules into 
-# _instances_ of classes and automatically removes them when out of scope.
+# _instances_ of classes and automatically removes them when out of scope. Some more 
+# appropriate word can be used instead of "as" or different syntax - it is just an idea.
 
 # Previous example with "as" keyword
 def do_parenting(parent, child)

diff --git a/dci_example.rb b/dci_example.rb
@@ -225,8 +225,9 @@ def self.receive_salary(human as EmployeeInteraction)
 # DCI usage example in Rails app
 # =========================================
 
-# In case of Rails, contexts should be called from controllers (if needed)
-# Contexts replace "managers", "services", "utility" modules/classes
+# In case of Rails, context methods should be called from 
+# controller actions, cron jobs, rake tasks.
+# Often contexts replace "managers", "services" modules/classes
 
 
 class ParentingController < ApplicationController

diff --git a/dci_example.rb b/dci_example.rb
@@ -253,8 +253,9 @@ def do_parenting
 # =========================================
 
 # !! With DCI many patterns are obsolete, like ActiveRecord or DataMapper 
-# (they are just trying to "emulate" DCI using classes - 
-# Classes Oriented Programming (COP)- correct me if I am wrong)
+# (they are just trying to "emulate" DCI ("instance plays role" part) 
+# using classes - Classes Oriented Programming (COP) 
+# - correct me if I am wrong)
 
 # For example if you need to save human data object into SQL DB 
 # you just create SQL database interaction (role)

diff --git a/dci_example.rb b/dci_example.rb
@@ -293,3 +293,8 @@ module HumanCassandraInteraction
   # ...
 end
 
+# or another approach could be like this
+human as HumanSqlDBInteraction, HumanCassandraInteraction
+human.save!   # with "one" method call save data both 
+              # into SQL and Cassandra databases. 
+
diff --git a/dci_example.rb b/dci_example.rb
@@ -272,7 +272,8 @@ module HumanSqlDBInteraction
   # ....
 end
 
-human.unextend HumanSqlDBInteraction  # remove SQL interaction, now we want to deal with Cassandra database
+human.unextend HumanSqlDBInteraction  # remove SQL interaction, now we want to 
+                                      # deal with Cassandra database
 
 # do you want to save human instance to 
 # "noSQL" Cassandra database? No problem

diff --git a/dci_example.rb b/dci_example.rb
@@ -272,6 +272,7 @@ module HumanSqlDBInteraction
   # ....
 end
 
+human.unextend HumanSqlDBInteraction  # remove SQL interaction, now we want to deal with Cassandra database
 
 # do you want to save human instance to 
 # "noSQL" Cassandra database? No problem

diff --git a/dci_example.rb b/dci_example.rb
@@ -15,7 +15,10 @@
 # 
 #   James Coplien: The DCI Architecture: Supporting the Agile Agenda
 #   https://www.youtube.com/watch?v=SxHqhDT9WGI
-#
+# 
+#   Matz reaction about this idea:
+#   https://twitter.com/yukihiro_matz/status/529854155314053120
+# 
 # my twitter: @kajamite
 
 

diff --git a/dci_example.rb b/dci_example.rb
@@ -16,6 +16,7 @@
 #   James Coplien: The DCI Architecture: Supporting the Agile Agenda
 #   https://www.youtube.com/watch?v=SxHqhDT9WGI
 #
+# my twitter: @kajamite
 
 
 

diff --git a/dci_example.rb b/dci_example.rb
@@ -222,7 +222,7 @@ def self.receive_salary(human as EmployeeInteraction)
 # =========================================
 
 # In case of Rails, contexts should be called from controllers (if needed)
-# Contexts replace "services","utility" modules/classes
+# Contexts replace "managers", "services", "utility" modules/classes
 
 
 class ParentingController < ApplicationController
@@ -253,13 +253,13 @@ def do_parenting
 # Classes Oriented Programming (COP)- correct me if I am wrong)
 
 # For example if you need to save human data object into SQL DB 
-# you just create SQL interaction (role)
-human as HumanSQLInteraction
+# you just create SQL database interaction (role)
+human as HumanSQLDBInteraction
 human.save! # <= human is saved into SQL database here
 
 # where HumanSqlInteraction could be something like this:
-module HumanSqlInteraction 
-  include SQLInteraction
+module HumanSqlDBInteraction 
+  include SQLDBInteraction
 
   has_many :bank_accounts
 

diff --git a/dci_example.rb b/dci_example.rb
@@ -207,7 +207,7 @@ def self.receive_salary(human as EmployeeInteraction)
 
 HomeContext.do_parenting(julia, severyn)
 
-julia.get_pocket_money_amount_today       # => Exception. Method give_pocket_money() 
+julia.get_pocket_money_amount_today       # => Exception. Method get_pocket_money_amount_today() 
                                           #    does not exist for "julia" object. 
 
 # And, for example if you do something like this:

diff --git a/dci_example.rb b/dci_example.rb
@@ -207,8 +207,8 @@ def self.receive_salary(human as EmployeeInteraction)
 
 HomeContext.do_parenting(julia, severyn)
 
-julia.parent.get_pocket_money_amount_today # => Exception. Method give_pocket_money() 
-                                           #    does not exist for "julia" object. 
+julia.get_pocket_money_amount_today       # => Exception. Method give_pocket_money() 
+                                          #    does not exist for "julia" object. 
 
 # And, for example if you do something like this:
 julia = human as ParentInteraction

diff --git a/dci_example.rb b/dci_example.rb
@@ -1,17 +1,17 @@
 # DCI EXAMPLE IN RUBY (with some prototype elements)
 # 
 # More info: 
-# 
-#   Creator of MVC & DCI, Trygve Reenskaug - Object Orientation Revisited. 
-#   Simplicity and power with DCI
-#   http://vimeo.com/43536416
-#
-#   James Coplien: Why DCI is the Right Architecture for Right Now
-#   http://www.infoq.com/interviews/coplien-dci-architecture
 #
 #   Creator of MVC & DCI, Trygve Reenskaug: DCI: Re-thinking the foundations of 
 #   object orientation and of programming
 #   http://vimeo.com/8235394
+#
+#   James Coplien: Why DCI is the Right Architecture for Right Now
+#   http://www.infoq.com/interviews/coplien-dci-architecture
+#
+#   Creator of MVC & DCI, Trygve Reenskaug - Object Orientation Revisited. 
+#   Simplicity and power with DCI
+#   http://vimeo.com/43536416
 # 
 #   James Coplien: The DCI Architecture: Supporting the Agile Agenda
 #   https://www.youtube.com/watch?v=SxHqhDT9WGI

diff --git a/dci_example.rb b/dci_example.rb
@@ -2,12 +2,16 @@
 # 
 # More info: 
 # 
-#   Author of MVC, Trygve Reenskaug: DCI: Re-thinking the foundations of 
-#   object orientation and of programming
-#   http://vimeo.com/8235394
-#   
+#   Creator of MVC & DCI, Trygve Reenskaug - Object Orientation Revisited. 
+#   Simplicity and power with DCI
+#   http://vimeo.com/43536416
+#
 #   James Coplien: Why DCI is the Right Architecture for Right Now
 #   http://www.infoq.com/interviews/coplien-dci-architecture
+#
+#   Creator of MVC & DCI, Trygve Reenskaug: DCI: Re-thinking the foundations of 
+#   object orientation and of programming
+#   http://vimeo.com/8235394
 # 
 #   James Coplien: The DCI Architecture: Supporting the Agile Agenda
 #   https://www.youtube.com/watch?v=SxHqhDT9WGI

diff --git a/dci_example.rb b/dci_example.rb
@@ -1,6 +1,4 @@
-# DCI EXAMPLE IN RUBY (prototype)
-# 
-# Main idea: Objects don't have responsibilities, roles do.
+# DCI EXAMPLE IN RUBY (with some prototype elements)
 # 
 # More info: 
 # 

diff --git a/dci_example.rb b/dci_example.rb
@@ -3,15 +3,18 @@
 # Main idea: Objects don't have responsibilities, roles do.
 # 
 # More info: 
+# 
+#   Author of MVC, Trygve Reenskaug: DCI: Re-thinking the foundations of 
+#   object orientation and of programming
+#   http://vimeo.com/8235394
 #   
 #   James Coplien: Why DCI is the Right Architecture for Right Now
 #   http://www.infoq.com/interviews/coplien-dci-architecture
 # 
 #   James Coplien: The DCI Architecture: Supporting the Agile Agenda
 #   https://www.youtube.com/watch?v=SxHqhDT9WGI
 #
-#   Trygve Reenskaug: DCI: Re-thinking the foundations of object orientation and of programming
-#   https://www.youtube.com/watch?v=cVkhEJq8Kow
+
 
 
 # =========================================

diff --git a/dci_example.rb b/dci_example.rb
@@ -152,7 +152,8 @@ def do_one_task_from_list(tasks)
 end
 
 
-# CONTEXTS. Contexts are essentially a Use Cases. 
+# CONTEXTS. What The-System-Does.
+# Contexts are essentially a Use Cases. 
 # Muster objects to play the roles. 
 # Inject role methods. Trigger interaction.
 # Place where roles are played. A collection of related possible scenarios.

diff --git a/dci_example.rb b/dci_example.rb
@@ -80,7 +80,6 @@ def do_parenting(parent as ParentInteraction, child as ChildInteraction)
 # =========================================
 # DCI stands for Data, Contexts and Interactions.
 
-
 # DATA. What The-System-Is. Classes without interaction code.
 
 class Human

diff --git a/dci_example.rb b/dci_example.rb
@@ -105,7 +105,7 @@ def say(text)
   end
 end
 
-# INTERACTIONS (Roles). 
+# INTERACTIONS (Roles). Role methods direct the execution of the Use Case.
 # 
 # Humans can play different roles in different contexts
 # like Parent, Child, Employee, etc.

diff --git a/dci_example.rb b/dci_example.rb
@@ -105,8 +105,7 @@ def say(text)
   end
 end
 
-# INTERACTIONS (Roles). Muster objects to play the roles. 
-# Inject role methods. Trigger interaction.
+# INTERACTIONS (Roles). 
 # 
 # Humans can play different roles in different contexts
 # like Parent, Child, Employee, etc.
@@ -155,6 +154,8 @@ def do_one_task_from_list(tasks)
 
 
 # CONTEXTS. Contexts are essentially a Use Cases. 
+# Muster objects to play the roles. 
+# Inject role methods. Trigger interaction.
 # Place where roles are played. A collection of related possible scenarios.
 # In different contexts same human object can play different roles.
 

diff --git a/dci_example.rb b/dci_example.rb
@@ -81,7 +81,7 @@ def do_parenting(parent as ParentInteraction, child as ChildInteraction)
 # DCI stands for Data, Contexts and Interactions.
 
 
-# DATA. Data is always pretty dumb.
+# DATA. What The-System-Is. Classes without interaction code.
 
 class Human
   attr_reader :name   # name of human
@@ -105,7 +105,9 @@ def say(text)
   end
 end
 
-# INTERACTIONS (Roles)
+# INTERACTIONS (Roles). Muster objects to play the roles. 
+# Inject role methods. Trigger interaction.
+# 
 # Humans can play different roles in different contexts
 # like Parent, Child, Employee, etc.
 

diff --git a/dci_example.rb b/dci_example.rb
@@ -2,8 +2,16 @@
 # 
 # Main idea: Objects don't have responsibilities, roles do.
 # 
-# More info: http://www.infoq.com/interviews/coplien-dci-architecture
-#            https://www.youtube.com/watch?v=SxHqhDT9WGI
+# More info: 
+#   
+#   James Coplien: Why DCI is the Right Architecture for Right Now
+#   http://www.infoq.com/interviews/coplien-dci-architecture
+# 
+#   James Coplien: The DCI Architecture: Supporting the Agile Agenda
+#   https://www.youtube.com/watch?v=SxHqhDT9WGI
+#
+#   Trygve Reenskaug: DCI: Re-thinking the foundations of object orientation and of programming
+#   https://www.youtube.com/watch?v=cVkhEJq8Kow
 
 
 # =========================================

diff --git a/dci_example.rb b/dci_example.rb
@@ -107,6 +107,7 @@ module ParentInteraction
   def get_pocket_money_amount_today
     amount = # ...     # complex logic of parent decision, probably 
                        # based on family budget and child behaviour
+                       # or something like rand(20)
 
     withdraw(amount)   # <= Human method is called                      
     amount             # <= return amount

diff --git a/dci_example.rb b/dci_example.rb
@@ -10,8 +10,8 @@
 # Proposals (ideas) to extend Ruby lang
 # =========================================
 
-# (proposal #1) New method .unextend() is added to Ruby, so we can effectively 
-# remove modules from instances. Optimized for speed.
+# (proposal #1) New method .unextend() (or curtail()?, withdraw()?) is added to Ruby, 
+# so we can effectively remove modules from instances. Optimized for speed.
 
 # For example:
 human.extend ParentInteraction    # we can do this right now in Ruby

diff --git a/dci_example.rb b/dci_example.rb
@@ -231,7 +231,7 @@ def do_parenting
 # Everything looks better when using DCI
 # =========================================
 
-# !! With DCI many patterns are absolete, like ActiveRecord or DataMapper 
+# !! With DCI many patterns are obsolete, like ActiveRecord or DataMapper 
 # (they are just trying to "emulate" DCI using classes - 
 # Classes Oriented Programming (COP)- correct me if I am wrong)
 
@@ -258,8 +258,8 @@ module HumanSqlInteraction
 human.save! # <= same human instance is saved 
             #    into "noSQL" database this time
 
-# where HumanCassadraInteraction could be:
-module HumanCassadraInteraction 
+# where HumanCassandraInteraction could be:
+module HumanCassandraInteraction 
   include CassandraInteraction
 
   attribute :name,   :string

diff --git a/dci_example.rb b/dci_example.rb
@@ -241,7 +241,8 @@ def do_parenting
 human.save! # <= human is saved into SQL database here
 
 # where HumanSqlInteraction could be something like this:
-module HumanSqlInteraction < SQLInteraction
+module HumanSqlInteraction 
+  include SQLInteraction
 
   has_many :bank_accounts
 
@@ -258,7 +259,8 @@ module HumanSqlInteraction < SQLInteraction
             #    into "noSQL" database this time
 
 # where HumanCassadraInteraction could be:
-module HumanCassadraInteraction < CassandraInteraction
+module HumanCassadraInteraction 
+  include CassandraInteraction
 
   attribute :name,   :string
   attribute :amount, :decimal

diff --git a/dci_example.rb b/dci_example.rb
@@ -133,7 +133,7 @@ def receive_salary(amount)
     # ...
   end
 
-  def do_job_task()
+  def do_one_task_from_list(tasks)
     # ...
   end
 
@@ -162,7 +162,7 @@ def self.do_parenting(parent as ParentInteraction, child as ChildInteraction)
 class JobContext # at job humans might play employee, managers, etc. roles
 
   def self.do_your_job(human as EmployeeInteraction)
-    human.do_job_task
+    human.do_one_task_from_list(@job.tasks)
   end # <= out of scope, EmployeeInteraction is removed 
       #    from human object
 

diff --git a/dci_example.rb b/dci_example.rb
@@ -240,10 +240,10 @@ def do_parenting
 human as HumanSQLInteraction
 human.save! # <= human is saved into SQL database here
 
-# where HumanSqlInteraction is:
+# where HumanSqlInteraction could be something like this:
 module HumanSqlInteraction < SQLInteraction
 
-  has_many :accounts
+  has_many :bank_accounts
 
   scope :active_users, -> { where(active: true) }
 
@@ -257,12 +257,14 @@ module HumanSqlInteraction < SQLInteraction
 human.save! # <= same human instance is saved 
             #    into "noSQL" database this time
 
-# where HumanCassadraInteraction is:
+# where HumanCassadraInteraction could be:
 module HumanCassadraInteraction < CassandraInteraction
 
-  partition_key :name
+  attribute :name,   :string
   attribute :amount, :decimal
 
+  partition_key :name
+
   # ...
 end
 
diff --git a/dci_example.rb b/dci_example.rb
@@ -190,8 +190,8 @@ def self.receive_salary(human as EmployeeInteraction)
 
 HomeContext.do_parenting(julia, severyn)
 
-julia.give_pocket_money(severyn)    # => Exception. Method give_pocket_money() 
-                                    #    does not exist for "julia" object. 
+julia.parent.get_pocket_money_amount_today # => Exception. Method give_pocket_money() 
+                                           #    does not exist for "julia" object. 
 
 # And, for example if you do something like this:
 julia = human as ParentInteraction

diff --git a/dci_example.rb b/dci_example.rb
@@ -24,8 +24,11 @@ def do_parenting(parent, child)
   child.extend ChildInteraction          # <= temporary extends "child" instance 
                                          #    with ChildInteraction module
 
-  parent.give_pocket_money(child)        # <= call ParentInteraction method which also calls 
-                                         #    "child's" ChildInteraction methods inside
+  amount = parent.get_pocket_money_amount_today  # <= call ParentInteraction method 
+
+
+  child.receive_pocket_money(amount)             # <= call ChildInteraction method
+
 
   child.unextend ChildInteraction        # UNextend ChildInteraction module from "child"
   parent.unextend ParentInteraction      # UNextend ParentInteraction module from "parent"
@@ -43,8 +46,9 @@ def do_parenting(parent, child)
   child as ChildInteraction             # <= temporary extends "child" instance
                                         #    with ChildInteraction module
 
-  parent.give_pocket_money(child)       # <= call ParentInteraction method which also calls 
-                                        #    child's ChildInteraction methods inside
+  amount = parent.get_pocket_money_amount_today       # <= call ParentInteraction method  
+  child.receive_pocket_money(amount)                  # <= call ChildInteraction method
+
 
 end                                     # <= out of scope, ParentInteraction module is automatically
                                         #    removed from "parent" instance and ChildInteraction 
@@ -53,7 +57,8 @@ def do_parenting(parent, child)
 
 # Previous example with "as" keyword in parameters list
 def do_parenting(parent as ParentInteraction, child as ChildInteraction)
-  parent.give_pocket_money(child)    
+  amount = parent.get_pocket_money_amount_today
+  child.receive_pocket_money(amount)
 end                                    
 
 
@@ -97,10 +102,14 @@ def say(text)
 # like Parent, Child, Employee, etc.
 
 module ParentInteraction
-  def give_pocket_money(child)
-    amount = 5 # five backs
-    withdraw(amount)
-    child.receive_pocket_money(amount)
+
+  # parent decides how much it wants to spend on pocket money for child
+  def get_pocket_money_amount_today
+    amount = # ...     # complex logic of parent decision, probably 
+                       # based on family budget and child behaviour
+
+    withdraw(amount)   # <= Human method is called                      
+    amount             # <= return amount
   end
 
   # other role related methods
@@ -109,8 +118,8 @@ def give_pocket_money(child)
 
 module ChildInteraction
   def receive_pocket_money(amount)
-    deposit(amount)
-    say('Thank you')
+    deposit(amount)                 # <= Human method is called   
+    say('Thank you')                # <= Human method is called   
   end
 
   # other role related methods
@@ -142,7 +151,8 @@ class HomeContext # at home humans might play parents and children roles
 
   # More than a subroutine - includes role / objects bindings
   def self.do_parenting(parent as ParentInteraction, child as ChildInteraction)
-    parent.give_pocket_money(child)
+    amount = parent.get_pocket_money_amount_today
+    child.receive_pocket_money(amount)
   end # <= out of scope, ParentInteraction is removed from 
       #    "parent" object, Child is removed from child object