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Attain Clean Code in Sitecore Solutions using Design Patterns

Mike Reynolds

Hanson Dodge Creative

@mike_i_reynolds

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What’s a Design Pattern?

• “General reusable solution to a commonly occurring

problem“• http://en.wikipedia.org/wiki/Software_design_pattern

• Describes how to solve a problem

• Can be across different contexts

• Provides a common language for developers

• Is not a cookie-cutter code solution!

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Design Patterns: History

• Proposed by Christopher Alexander (1970s)

• A Pattern Language: Towns, Buildings, Construction (

http://amzn.to/1BtaaIH)

• Kent Beck and Ward Cunningham applied the concept

to programming (1987)

• Presented results at Object-Oriented Programming, Systems,

Languages & Applications (OOPSLA)

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Design Patterns: History

• Gang of Four (GoF) Book (1994)

• Design Patterns: Elements of Reusable Object-Oriented

Software. (http://amzn.to/UPNN2F)

• Erich Gamma, Richard Helm, Ralph Johnson, and John

Vlissides

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Design Patterns: Examples

• Adapter

• Decorator

• Composite

• Chain-of-responsibility

• Null Object

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Adapter Pattern

• Allows the interface of an existing class to be used from

another

• A “wrapper”

• Makes existing classes work with others without modifying

their source code

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Adapter Pattern

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Decorator Pattern

• Encapsulates an object with the same interface

• Also a “wrapper”

• Adds/removes/alters functionality on the inner instance

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Decorator Pattern

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Composite Pattern

• Encapsulates a collection of objects with the same

interface

• Treats the entire collection as one object

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Composite Pattern

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Chain-of-responsibility Pattern

• Composed of command objects and a series of

processing objects

• Each processing object executes specific command

objects

• Processing objects are chained together

• think linked list

• Processing objects are invoked in a cascading manner

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Null Object Pattern

• Represents the “null” state of an object

• Provides methods with no behaviour

• Removes the need of client code performing null

checks

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Learn More!

• Recommend Books

• http://amzn.to/UPNN2F

• http://amzn.to/1ppJHeH

• http://amzn.to/1EZEa3z

• http://amzn.to/1bSAYsh

• Blog posts

• http://bit.ly/1E7J7JO

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Get In Touch!

Blog: http://sitecorejunkie.com

Twitter: @mike_i_reynolds

LinkedIn: http://linkd.in/1Csu1N8

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Questions?

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Thank you