You’re going to learn about a number of design patterns. You’re going to work out some of them in code. You’re going to apply most of the patterns we learn today towards an example Model View Controller application Quick Overview

You’re going to learn about a number of design patterns.

You’re going to work out some of them in code.

You’re going to apply most of the patterns we learn today towards an example Model View Controller application

Are reusable solutions to common design problems Improve the development workflow Help teams to work together efficiently Help you deal with change Design Patterns…

Are reusable solutions to common design problems

Improve the development workflow

Help teams to work together efficiently

Help you deal with change

are not Algorithms are not Architectural Patterns are not finished designs are not written in stone Design Patterns…

are not Algorithms

are not Architectural Patterns

are not finished designs

are not written in stone

Singleton Pattern The one and only

The one and only

has only ONE instance ever is created only when needed assures that every object in an application is using the same resource (global access point) The Singleton Pattern…

has only ONE instance ever

is created only when needed

assures that every object in an application is using the same resource (global access point)

Singleton Pattern Lab

Use this pattern when you need one and only one instance of a class The package mx.managers are all singletons DragManager CursorManager HistoryManager FocusManager etc… Singleton Pattern Tips

Use this pattern when you need one and only one instance of a class

The package mx.managers are all singletons

DragManager

CursorManager

HistoryManager

FocusManager

etc…

Command Pattern Execute Here 

Execute Here 

encapsulates method invocation. is used to carry out ‘orders’ like authenticate user process form sit on cat often encapsulates an algorithm. often performs tricky operations. The Command Pattern…

encapsulates method invocation.

is used to carry out ‘orders’ like

authenticate user

process form

sit on cat

often encapsulates an algorithm.

often performs tricky operations.

Command Pattern Lab

Observer Pattern

defines a one to many relationship between objects so when one object changes, all the observers are notified. is also known as Publish and Subscribe. is used in event driven design. reduces coupling between classes, but they can still interact. The Observer Pattern…

defines a one to many relationship between objects so when one object changes, all the observers are notified.

is also known as Publish and Subscribe.

is used in event driven design.

reduces coupling between classes, but they can still interact.

Event Dispatcher Observer Observer Observer In this lab, we’re going to leverage the Observer Pattern implementation built into the Flash Player. Observer Pattern Lab

Proxy Pattern May I Help You?

May I Help You?

stands in for and provides access to another object. can control or guard access can be used to manage instantiation A Proxy…

stands in for and provides access to another object.

can control or guard access

can be used to manage instantiation

The Virtual Proxy stands in for an object that is expensive to create is not immediately available The Loader class is a Virtual Proxy. The Virtual Proxy DisplayObjectContainer Loader Sprite Stage MovieClip

The Virtual Proxy stands in for an object that

is expensive to create

is not immediately available

The Loader class is a Virtual Proxy.

The Remote Proxy stands in for a remote object and, delegates requests to a remote object manages communication with remote object The Remote Proxy Image Search Flickr API Remote PhotoProxy Remote Service Your Application

The Remote Proxy stands in for a remote object and,

delegates requests to a remote object

manages communication with remote object

In this lab, we’re going to implement a remote proxy and learn about a time saving technique. Proxy Pattern Lab Image Search Flickr API Remote PhotoProxy Remote Service Your Application

In this lab, we’re going to implement a remote proxy and learn about a time saving technique.

Façade Pattern Hiding Complexity

Hiding Complexity

The Façade pattern simplifies access to a collection of objects. Often implemented as a singleton (only need one) Hides the complexity of underlying objects Façade Pattern… Application Facade Model View Controller

The Façade pattern simplifies access to a collection of objects.

Often implemented as a singleton (only need one)

Hides the complexity of underlying objects

Adapter Pattern a.k.a. Wrapper

a.k.a. Wrapper

The Adapter pattern converts and translates the API of one object to the API of another object. often applied when reusing legacy code providing a common API to several 3 rd party libraries or algorithms Adapter Pattern… Music Player MP3 Adapter FLAC Adapter AC3 Adapter FLAC Decoder MP3 Decoder WAV Decoder

The Adapter pattern converts and translates the API of one object to the API of another object.

often applied when reusing legacy code

providing a common API to several 3 rd party libraries or algorithms

Mediator Pattern Central Communication

Central Communication

The Mediator Pattern is used to centralize complex communication and control between related objects. Mediator Pattern Application Username Textbox Password Textbox Submit Button New Account Form Account Form Mediator

The Mediator Pattern is used to centralize complex communication and control between related objects.

Model View Controller A collection of patterns

A collection of patterns

The MVC Pattern is a collection of patterns used to address the challenges presented by rich user interfaces. Model View Controller (MVC)

The MVC Pattern is a collection of patterns used to address the challenges presented by rich user interfaces.

MVC brings order to applications and application development by, decoupling the user interface of an application from the data model and business logic. allow each of the elements to be changed without impacting the other. improve communication and understanding between developers so they can work independently and more efficiently. Model View Controller (MVC)

MVC brings order to applications and application development by,

decoupling the user interface of an application from the data model and business logic.

allow each of the elements to be changed without impacting the other.

improve communication and understanding between developers so they can work independently and more efficiently.

Model View Controller Command Façade Proxy Mediator Observer Notification Model View Controller Command Delegate Service CairngormEvent Cairngorm Quick Comparison

Model

View

Controller

Command

Façade

Proxy

Mediator

Observer

Notification

Model

View

Controller

Command

Delegate

Service

CairngormEvent

Platform independent (AS2, AS3, Coldfusion, Java, C#, Perl, Python, PHP, Ruby) Excellent Documentation and Active Development Community Winner at SilvaFUG between 9 frameworks Cairngorm What I Like About PureMVC

Platform independent (AS2, AS3, Coldfusion, Java, C#, Perl, Python, PHP, Ruby)

Excellent Documentation and Active Development Community

Winner at SilvaFUG between 9 frameworks

PureMVC Conceptual Diagram

Flash/Flex Development Services : Yossi Cohen [email_address] 09-8850956, 054-5313092 Flash / Flex Courses & Seminars: Alona Ashkenazi [email_address] 09-8651933 www.dsp-ip.com Giborey Israel 20, POB 8323, Netanya Office Phone: 09-8850956, Fax: 050- 8962910 DSP-IP Contact information

Flash/Flex Development Services :

Yossi Cohen

[email_address]

09-8850956, 054-5313092

Flash / Flex Courses & Seminars:

Alona Ashkenazi

[email_address]

09-8651933

Thank You