tions Synopsis: User suitable for chart that is be considered that consider Organizations high volume applications may i applications.

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1 A Comparison of User Interface Migrated Legacy Applicat tions Technologies for use in Synopsis: User interface modernization of legacy IBM i applications is most often consideredd in terms of getting the applications to run in a browser. Although browser based applications may be suitable for many modernization efforts, there aree some features of other presentation layer technologies that should be considered. This whitepaper provides a comparison chart that is useful when deciding whichh technologies should be considered during migration. Organizations that consider migrating legacy IBM i applications to the.net environment usually start with the assumption that the user interface for the replatformed application will be hosted in a web browser. After all, the browser is a universall client, in the sense that all modern client operating systems and devices provide support for one or more browsers. Although the browser can be an excellent choice for many modernized applications, there may be unique application requirements thatt make the browser a suboptimal choice. For example, applications that require access to special devices (e. g., bar code printers) or are characterized as high volume data entry applications may be difficult to deploy successfully in a browserbe the most fitting choice for the user interface. However, when migrating legacy IBM i applications ( brown based environment. For new, or green field, application development, the browser may indeed field ), the choice of user interface is not so cut and dried. Beforee starting a migration effort, the requirements of the applications and the features provided by various user interface technologies should be well understood. A Comparison of User Interface Technologie es The following chart compares three of the user interface technologies that can be considered when migrating applications to the Microsoft.NET environment. The chart is not meant to be an exhaustive comparison of the technologies, but rather, serves as a quick reference to features that are often important when considering migrationn of legacy IBM i applications. For each feature, you can compare the factors that are important to you in your applications and determinee which user interface technology might be the bestt fit for your applications. A Comparison of User Interface Technologies for usee in Migrated Legacy Applications Copyright 2011, PBSI. ALL RIGHTS RESERVED 1

2 Note: the following abbreviations are used in this chart AJAX Asynchronous JavaScript and XML App V Microsoft Application Virtualization technology CSS Cascading Style Sheet MSMQ Microsoft Message Queuing OOB Out of Browser WCF Windows Communication Foundation WPF Windows Presentation Foundation Feature ASP.NET Web Forms Windows Forms / WPF Silverlight U/I Technology HTML, CSS, JavaScript Interpreted by browser when rendered. Native Windows code / managed code (.NET Framework components) Rendered by underlying OS at runtime. Managed code (.NET Framework components) Rendered by underlying OS at runtime. Keyboard functions Some keys are claimed by browser. keys. keys when running Out of Browser (OOB). Mouse interaction Some mouse interactions are claimed by browser. mouse events. mouse events when running OOB. Printing Browser can print the web page, but no native support in browser for printing from the application. Application controls printing. Full access to all printing features. Application controls printing. Access to printing features, but not as well supported as WinForms / WPF. Deployment of client application No deployment, application is delivered through browser. Application is installed using Windows installer technology. Application is delivered through browser. All changes to client application are immediately available with no client-side activity required to deploy the changed application. Install images can be delivered via Web downloads or can be delivered on install media (CD, DVD). Client must initiate install process to have access to an updated version of an application. The.NET Framework must be installed on the client PC to support the applications. This is typically done when Windows is installed or when Windows Update runs. Applications can also be deployed using the Microsoft Application Virtualization (App-V) features. Applications can be tagged as being Out of Browser (OOB) capable. User can optionally install application to run OOB. After the initial download and install through the browser, the application is accessed as a local application. Any changes to the application are delivered through the browser. Changed applications can be tagged so that the changed application must be installed, or tagged as optional. After installing in OOB mode, the changed application replaces the previous local version. Requires an initial install of the.net Framework Client Profile, which is a web-based install. Occasional updates to the.net Framework Client Profile are made available from Microsoft and can be automatically installed or installed upon request by the user. 2

3 Feature ASP.NET Web Forms Windows Forms / WPF Silverlight Access to database, other server-side features All access is provided by serverside programs. Fat client : database providers can be installed on client PC, application can use the providers to access server-side resources. (Note: this technique is not recommended by PBSI). Access to server-side programs is via web services. Client programs interact with server programs. Server programs provide all access to server-side resources. Thin client : access to serverside programs is via web services. Client programs interact with server programs. Server programs provide all access to server-side resources. Underlying communications between server and client HTTP/HTTPS Web form is rendered by sending HTML, JavaScript, CSS code and the application data to the browser. JavaScript and CSS code may be cached in the browser. HTML is generated for each page request and is returned with the application data. AJAX techniques can be used to improve the response time when transmitting data to be viewed on the same page. Windows Communication Foundation (WCF) services or ASP.NET web services. WCF services can be configured as: Web service MSMQ (message queuing) Sockets For WCF web services, can use.net specific techniques to compress the data stream that is transmitted. Windows Communication Foundation (WCF) services. Can use.net specific techniques to compress the data stream that is transmitted. Communications error Completely browser dependent. Communications errors usually block until the browser timeout expires, at which point the browser displays a browserspecific error message. Limited ability for application to know about or recover from a communications error. Application can be given control when a communication error occurs. Application can invoke the communication request again or take other error-recovery actions. For unresolvable errors, application can display application-specific error message to user. Application can be given control when a communication error occurs. Application can invoke the communication request again or take other error-recovery actions. For unresolvable errors, application can display application-specific error message to user. 3

4 Feature ASP.NET Web Forms Windows Forms / WPF Silverlight Summary No client-side deployment required, requires only a current level browser. Can be accessed from any device with a browser. Constraints on use of keyboard, mouse interaction and printing. Communications optimization using AJAX, but may be of limited value in an application where many different web forms are used. Limited ability to provide meaningful interaction with end user when a communications error occurs. Easiest deployment Limitations on user interaction Limitation on communication Requires initial deployment of application by support personnel or end user. Updates to application require user-initiated action. Can be installed on any Windows PC that has the.net Framework installed (version as required by the application). The.NET Framework is available as a no-charge Windows feature from Microsoft. May be deployed using Microsoft App-V, to eliminate installation of applications on client PC. No constraints on use of keyboard, mouse, printing. Can attach to and work with other devices on the PC. Can make use of communications optimization techniques. Can include error recovery for communications errors. Deployment required (initial and updates) Best for user keyboard/mouse interaction Best for communication Application can be run in a browser that has the nocharge Silverlight plug-in installed. Silverlight is supported in most Windowsbased browsers, the Mac browser and a few other browser types. Can also deploy applications to run Out-of-Browser. Applications are updated through the browser, if installed as OOB applications. If an application is not installed OOB, any updates to the application are available to the user upon accessing application in the browser. Complete access to keyboard and mouse features when running OOB. Printing is supported, but print capabilities are not as well supported as WinForms / WPF. Can use optimized WCF services for communications. Can include error recovery for communications errors. Can be a nodeployment environment or can be a light-touch (OOB) deployment Better keyboard/mouse support than Web Forms Better communications than Web Forms 4

5 Summary The PBSI.NETigration technology provides migration of legacy IBM i program assets to the Microsoft.NET environment. Before migration, PBSI will help you develop a comprehensive, documented migration plan that identifies the user interface technology to be used for each green screen program that is migrated. Using the PBSI ScatterGraph technology, PBSI will help you determine how program families are to be migrated and suggest how the user interface choices within a program family can be harmonized. During the code migration process, legacy IBM i green screen programs become serviceenabled applications. That means that the user interface is decoupled from the application program, and can be easily changed or enhanced after the migration is completed. In fact, the same migrated application can be used with multiple user interfaces, providing support for new technologies as they become available. There is far more to a successful modernization effort than simply deploying green screens into the browser. With the PBSI.NETigration process, you can preserve the business value of your existing applications and at the same time, provide the best user interface consistent with your requirements. For More Information Natalie (Kilner) Hughes President and CEO Packaged Business Solutions, Inc. (800) nataliek@pbsilink.com 5