Object Thinking

The Philosophy of Development formalism -vs- hermeneutics From Philosophy to Culture mentoring, metaphor & vocabulary From Culture to Practice object discovery & thinking

The Philosophy of Development

formalism -vs- hermeneutics

From Philosophy to Culture

mentoring, metaphor & vocabulary

From Culture to Practice

object discovery & thinking

Formalism/Determinism (software engineering) uses traditional thinking -vs- Hermeneutics/Postmodernism (extreme programming) uses object thinking

Formalism/Determinism

(software engineering)

uses traditional thinking

The Object Thinking Manifesto Advocacy of behavioralism Antagonistic towards formalism Emphasis on analysis and conceptualization Philosophy of extreme programming Prefers the autonomous to the autocratic

Advocacy of behavioralism

Antagonistic towards formalism

Emphasis on analysis and conceptualization

Philosophy of extreme programming

Prefers the autonomous to the autocratic

The Object Thinking Manifesto Better people write better code - not better tools

Better people write better code

- not better tools

“ Let there be no doubt that object-oriented design is fundamentally different than traditional structured design approaches: it requires different ways of thinking about decomposition, and it produces software architectures that are largely outside the realm of the structured design culture.” Grady Booch, 1991

“ Let there be no doubt that object-oriented design is fundamentally different than traditional structured design approaches:

it requires different ways of thinking about decomposition, and it produces software architectures that are largely outside the realm of the structured design culture.”

Grady Booch, 1991

“ Let there be no doubt that object-oriented design is fundamentally different than traditional structured design approaches: it requires different ways of thinking about decomposition, and it produces software architectures that are largely outside the realm of the structured design culture .” Grady Booch, 1991

“ Let there be no doubt that object-oriented design is fundamentally different than traditional structured design approaches:

it requires different ways of thinking about decomposition, and it produces software architectures that are largely outside the realm of the structured design culture .”

Grady Booch, 1991

Observing the Object Difference Traditional thinking Object thinking Data Structure operationX operationY operationZ

Traditional thinking

Object thinking

Anthropomorphization is the attribution of human characteristics to inanimate objects, animals, forces of nature, the unseen author of things, and others.

Anthropomorphization

is the attribution of human characteristics to inanimate objects, animals, forces of nature, the unseen author of things, and others.

“… if the diagram is an accurate depiction of an object, what is the difference between an object and a COBOL program?”

“… if the diagram is an accurate depiction of an object, what is the difference between an object and a COBOL program?”

“ There is none. A COBOL program encapsulates data and operations and allows communication among programs. Object development – using this model – will have a tough time being anything more than the creation of lots of tiny COBOL programs.”

“ There is none. A COBOL program encapsulates data and operations and allows communication among programs. Object development – using this model – will have a tough time being anything more than the creation of lots of tiny COBOL programs.”

Object Depictions Entity UML Customer ID# dob gender fname … getID# setID# getDOB# setDOB# … Customer id# dob gender fname lname mi honorific generational …

Entity

Object Depictions Object (Class-Responsibility-Collaboration) Customer ID self describe self indicate desires make decisions confirm information

Encapsulation via Properties public class Customer { public string Name { get { return _name ; } set { // validate here _name = value ; } } private string _name ; } Known as information hiding Traditionally taught as a key precept of OO But many XP advocates say they should not be tested … why? Why do objects keep trying to change type? Is there a better way?

public class Customer

{

public string Name

{

get { return _name ; }

set

{

// validate here

_name = value ;

}

}

private string _name ;

}

Known as information hiding

Traditionally taught as a key precept of OO

But many XP advocates say they should not be tested … why?

Why do objects keep trying to change type?

Is there a better way?

Self-Describing Objects public class Customer : Dictionary < Uri , Object > { } Provides a property bucket Looks alien to traditional thinking Violates traditional encapsulation principles How is validation carried out?

public class Customer

: Dictionary < Uri , Object >

{ }

Provides a property bucket

Looks alien to traditional thinking

Violates traditional encapsulation principles

How is validation carried out?

Self-Evaluating Rules Evaluate self-describing objects at runtime Promote type re-use via separation of concerns Embody data validation rules, business rules, or any other constraint

Evaluate self-describing objects at runtime

Promote type re-use via separation of concerns

Embody data validation rules, business rules, or any other constraint

Demo Self-Describing Objects & Self-Evaluating Rules

So all my objects should be self-describing?

So all my objects should be self-describing?

Having a hammer does not make everything a nail

Having a hammer

does not make everything a nail

Non-Self-Describing Objects Primitives bool, int, float, enum, etc. Some Standards html elements, xpath predicates, industry, etc. Self-Describing Objects tend to be actors

Primitives

bool, int, float, enum, etc.

Some Standards

html elements, xpath predicates, industry, etc.

Self-Describing Objects tend to be actors

Issues Currently no standard supporting framework I am considering a CodePlex or SourceForge project Limited knowledge, few publications, no examples Just try googling for the key terms… Steep learning curve Hard to ‘unlearn’ traditional thinking Few practitioners or evangelists

Currently no standard supporting framework

I am considering a CodePlex or SourceForge project

Limited knowledge, few publications, no examples

Just try googling for the key terms…

Steep learning curve

Hard to ‘unlearn’ traditional thinking

Few practitioners or evangelists

Links http://del.icio.us/alan.dean/object-thinking http://thoughtpad.net/alan-dean Email [email_address] © MMVII

Links

http://del.icio.us/alan.dean/object-thinking

http://thoughtpad.net/alan-dean

Email

[email_address]

© MMVII