Implementing Design Patterns

1
Implementing Design Patterns

• With CFCs, MVC and other Design Patterns

2
What will this presentation cover

• The MVC Design Pattern
• Using MVC in Fusebox
• Using MVC in Mach-II
• Data Access Object Pattern
• Abstract Factory Pattern
• Facade Pattern
• Decorator Pattern
• Gateway Pattern

3
What is MVC

• MVC stands for Model View Controller
• Source code in an application is divided into
  three distinct parts
• The Model is used to create a structure to store
  the data for the application
• The View is the presentation later for the
  application
• The controller handles the logic of the
  application

4
Fusebox and MVC

• Fusebox is not a true Object Oriented Framework
• Version 3 of Fusebox allows separation of view
  from the controller
• Version 4 allows for full MVC without cfmoduling
• This is accomplished by compiling the runtime
  files

5
Fusebox and MVC

• Use circuits to set up MVC

ltfuseboxgt ltcircuitsgt ltcircuit alias"m"
path"model/" parent""/gt ltcircuit alias"v"
path"view/" parent""/gt ltcircuit alias"main"
path"controller/" parent""/gt lt/circuitsgt
6
Mach-II and MVC

• Mach-II is an Object Oriented framework
• Mach-II config file acts as a controller
• Model is based on CFCs
• Views are cfm templates

7
GoF Patterns

• 10 year old book by Eric Gamma, Richard Helm,
  Ralph Johnson and John Vlissides
• These patterns represent different designs that
  can be used in different Object Oriented
  applications
• Examples are in C and Smalltalk
• ISBN number 0-201-63361-2

8
Gang of Four

• They divide patterns into three different groups
• Creational Patterns
• Structural Patterns
• Behavioral Patterns

9
Data Access Object Pattern

• Acts as a connector between CFC model and
  database, singleton
• CFC based Objects are passed to DAO objects
• DAOs handle basic CRUD functionality
• Should use for single record operations
• Query results should be handled with gateways

10
Data Access Object Pattern

• ltcfset personDAOObj createObject(component,
  personDAO) /gt
• ltcfset personObj createObject(component,
  person) /gt
• ltcfset personObj.setPersonName(Dave) /gt
• ltcfset personDAOObj.save(personObj) /gt

11
Abstract Factory Pattern

• Used to create families of related and dependant
  Objects
• Does not require specifying a concrete class
• Do not need to use createObject() every time to
  create an object

12
Abstract Factory Pattern

• personDAOObj appFactory.createDAO(person)
• addressDAOObj appFactory.createDAO(address)
• phoneDAOObj appFactory.createDAO(phone)

13
Session Façade Pattern

• Allows for a unified interface to a set of
  interfaces in a subsystem
• This is used to create a high level interface to
  make it easier to use lower level systems
• Good example is the Bookstore shopping cart

14
Decorator Pattern

• Add additional responsibilities to an object.
• Gof example is a scrollbar for a text box
• A Good CFC use would be to add functionality that
  does not exist for a model object. Person/Address
  relationship.
• Provides an alternative to Subclassing

15
Gateway Pattern

• Gateway Pattern should be used for exchanging
  data with common types, such as an query
• Use gateway as a bridge between the object and a
  database
• Encapsulate queries into objects

16
CFC Design Pattern Resources

• http//www.corfield.org/blog/
• http//clearsoftware.net/client/
• http//www.mattwoodward.com/blog/
• http//www.doughughes.net/
• http//www.dcooper.org/blog/client/
• http//www.briankotek.com
• http//www.mossyblog.com/