Designers Challenge Preparing Applications for the Future Using

Designer’s Challenge Preparing Applications for the Future Using MVC Concepts By Don Bakke President, SRP Computer Solutions, Inc.

What is MVC? • At the very least it’s just another computer acronym…Model-View-Controller • It might be new to you but it’s been around for 30 years • In varying degrees it is probably something you are already doing but didn’t know it • But before we explain MVC any further…

Audience Poll • Who here already has been or will plan to integrate an Open. Insight application with an alternative visual interface and/or with an alternative database server? • If you answered “yes” to this question then MVC should be of interest to you…

“The Shape of Things to Come” Percentage of Topics Related to Alternative Connections 40. 00% 35. 00% 30. 00% 25. 00% 20. 00% 15. 00% 10. 00% 5. 00% 0. 00% 2002 2004 2005 2007 2008 2010

Model-View-Controller – A Bit of History • Architectural pattern for designing software where an application is described in and designed in three separate layers: – Model = Relates to the application’s database and business logic – View = Relates to the application’s presentation of the data – Controller = Relates to the application’s flow and ties the other layers together • Generally assumes that application layers are loosely connected

Model-View-Controller – A Bit of History • Coined in the late 70’s and made popular in the early 80’s with Smalltalk • Developed with Object Oriented technology in mind • Early versions assumed dumb clients • Spin-off versions include Model-View-Presenter, Model -View-Template, and Model-View. Model

Who Needs to Know MVC? • Anyone who needs to substitute or allow for alternative layers with minimal code rewrite – Presentation layer - WPF, Flex, HTML, i. Phone, web. OS – Data layer - SQL, U 2, Amazon. S 3, Google App Engine (e. g. Cloud resources – Tom Wilson) – Leverage existing resources – Tom Wilson • Anyone who wants easier code management and documentation • Anyone who develops with teams who are focused on a specific layer of the application

Who Needs to Know MVC? • Anyone who wants better unit testing of their code • Anyone who wants more reusability of their code • Anyone who wants more scalability in their application • Ask a Java, PHP, Ruby, . NET, or Cocoa developer

Who Doesn’t Need to Know MVC? • Anyone who prefers a ‘git-r-done’ approach • Anyone who never intends to work outside of Open. Insight

Model-View-Controller – A Closer Look • Disclaimers – I am not an MVC purist or expert – Much of what I am presenting is a “work-inprogress” effort – While MVC philosophy is always the same, pundits will differ on how to apply it

Model-View-Controller – A Closer Look • Separation of Concerns (Layers) – Model API Events Requests – View Notifications View Controller Model – Controller API Results • Presents Data User Receivers. Data Userto Inputs Handles Responses • Handles Event Processing Calls Appropriate Resources Notifications Business Logic

Model-View-Controller vs. n-Tier Architecture View Presentation Tier Controller Model Logic Tier Business Logic Physical Data MVC Data Tier n-Tier

Amazon’s Shopping Cart

AREV

Open. Insight

Flex - Form Design Courtesy of Clay Borne

Calculate Shipping - Flowchart Start Have Zipcode? No Yes Set “Missing Zipcode” Error Shipping Logic Return Shipping Costs Display Shipping Cost (Color Red if too much) Display Error End

MVC Examples – Side by Side Comparison Basic MVC Pure OI OI Form View Controller Basic+ (Commuter) In Process Engine Basic + Model Linear Hash Basic+ (MFS) HTML / OI Flex / OI HTML Javascript Flex/Flash Action. Script OECGI/2 Basic+ Linear Hash Basic+ (MFS) OI/ SQL OI Form Basic+ (Commuter) In Process Engine Basic + SQL Basic+ or Direct

Final Thoughts • Don’t swallow the elephant – Take one bite at a time – Translation: Don’t force yourself to convert everything to MVC. Ease into it • Don’t force a square peg in a round hole • Build a framework and standards to make this easier

Thank you Any Questions?