Design Patterns and ColdFusion: Exploring Object Based Programming

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Design Patterns and ColdFusion Exploring Object
Based Programming

• Dan Blackman
• www.muddbrick.com

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Dan Blackman

• Founder and Senior Consultant
• Mudd Brick Inc, Dallas, Tx
• Certified Adobe Instructor Flex, ColdFusion,
  Flash
• Experience 12 Years ColdFusion, Flash and Flex

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Setting Expectations

• I am not a Architect but I play one on TV
• My name does not end in Lehman, Forta, Majano
  etc.
• There will be NO debate here todayJust
  demystification of a cryptic topic.
• Lets have an interactive dialog

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Objectives

• Design Patterns The Why?
• Identification of Core Design Patterns
• Frameworks
• Shut up and Show me some code!!!
• Summary and Questions

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Design Patterns The Why!?

• What is the main goal of building ColdFusion/
  Flex Applications?

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Design Patterns The Why?
SOA Service Oriented Architecture
Mind the Gap - Marcel Boucher http//blogs.adobe.
com/mtg/2008/04/implementing_soa_principals_in.htm
l
Duane Nickul, et al http//www.adobe.com/enterpri
se/pdfs/Services_Oriented_Architecture_from_Adobe.
pdf
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Design Patterns The Why?
SOA Service Oriented Architecture
The ultimate value of SOA is the ability to
combine automated business services to create new
market offerings that may reduce time-to-market
and development costs." Terry Borden and
Bill Mitlehner
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Design Patterns The Why?
SOA
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Design Patterns The Why?

• FACT Refactoring patterns into existing code is
  much more difficult than writing an application
  correctly the first time.

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Design Patterns The Why

• Scalability Can your application support a
  large number of concurrent users?
• Maintainability the everyday fight we have with
  our inner-self and management.
• Reusability Break down your application into
  small chunks. Forces us to build structure into
  our applications.

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Design Patterns The Why
Lets look at some Spaghetti CodeMost of you
have written code like this!!!
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Design Patterns The Why
MORAL of the STORY?
An Architect does not construct a building with
out a blueprint, Why are YOU then, building
applications without a solid foundation? Me
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Identification of Core Design Patterns

• What are design patterns and how do I use them?

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Identification of Core Design Patterns

• Design Pattern Definition
• design pattern is a general reusable solution to
  a
• commonly occurring problem in software design. A
• design pattern is not a finished design that can
  be
• transformed directly into code.
• In short, design patterns provide a foundational
  blueprint for software development.
• Patterns are NOT code, they are designs we apply
  to our application code.

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Identification of Core Design Patterns

• Core Patterns
• MVC Design Pattern
• Singleton Pattern Application.cfc
• Service Object Pattern
• Front Controller/ Command Patterns
• Business Delegate Pattern
• DAO/ Gateway Patterns
• Value/ Data Transfer Object Pattern

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Identification of Core Design Patterns
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Identification of Core Design Patterns

• Model View Controller
• Allows for a clear separation between User
  Interface Objects and the underlying data model
• Elements of MVC include
• Model, which manages data elements and responds
  to queries
• about its state and to instructions to change
  its state
• View, which manages a rectangular area of the
  display and is
• responsible for presenting the data
• Controller, which handles events from the user
  and system that
• affect the model and view
• These application components allow the separation
  of the following
• User interaction
• Modeling of the external world (data)
• Visual feedback to the user

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Identification of Core Design Patterns

• Singleton Design Pattern
• Used to restrict the instantiation of a class to
  a single instance.
• Application.cfc - OnApplicationStart

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Identification of Core Design Patterns

• Service Objects
• Allows Encapsulation of Business Logic in a
  single service interface.
• LoginService.cfc
• EmailService.cfc
• ZipValidationService.cfc

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Identification of Core Design Patterns

• Front Controller/ Command Patterns
• The Front Controller is a single component
  created to handle all system requests.
• Controls and coordinates processing of each user
  across multiple requests.
• Employs Command (workers) in order to carry out
  requests.
• Commands can be reused throughout the application
  across multiple Views

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Identification of Core Design Patterns

• Business Delegate Pattern
• A simple class that acts to create separation
  between the Presentation/ Web tier client (HTML/
  RIA) and the business tier on the back-end.
• Provides remote access from Web clients to
  important business tier services.

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Identification of Core Design Patterns

• DAO/ Gateway Patterns
• DAO Data Access Object Provides CRUD
  operation methods for specific business objects.
• Table Data Gateway (Fowler) Provides a similar
  set of data access methods. Commonly used in
  ColdFusion applications for bulk data access.
  (i.e. queries that return large data sets)

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Identification of Core Design Patterns

• Data Transfer / Value Objects
• Also called beans, this pattern provides a way
  to transfer data back and forth to the Web Client
  tier
• Value Objects are NOT packaged exactly like
  Database tabels
• Designed using a UML Class diagram

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Frameworks

• Various Frameworks implement design patterns
• ColdFusion
• ColdBox
• Mach-II
• Model-Glue
• ColdSpring
• Flex
• Pure MVC
• Cairngorm
• Model-Glue
• Swiz
• Mate

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Shut up and show me some code!!!

• When building an application, where do you start?
• View ? Controller ? Model?
• Model ? Controller ? View
• You have a database Where do I go from here!?
• Lets check out a real scenario!

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Questions?Dan BlackmanMudd Brick Inc.Dallas,
TXdblackman_at_muddbrick.com