WOW and IBM HATS

Introduction

WOW and HATS are two products that provide developers the ability to bring iSeries data to the web. Both have their place in the world of application development yet serve very different purposes. This document highlights many of the questions that arise from iSeries customers making decisions to purchase one product over another but may be confused because of the overlap of the products. This document should help assist RPG shops in their evaluation of how to best utilize legacy code and iSeries data in developing web applications. It should be noted that some of the questions that arise are not always about the application; they also include issues surrounding hardware and operating systems.

Comparing Technologies

WOW is primarily used to create new web based applications using existing Legacy system data. These new applications can access existing database files, as well as RPG, COBOL, and CL programs. WOW does not convert existing IBM iSeries 5250 screens to GUI but can be used to quickly replace these screens and present them in a format that may be more appropriate to a new user of the system (such as a customer, manufacturers rep or vendor). At the same time, the WOW product can provide powerful features such as application security, dynamic searching, sorting, inserting, deleting of information and automatic Excel or XML downloads.

WebFacing is a technology where existing screens are converted at development time to Java JSP files which can serve as the graphical user interface (GUI). The 5250 screens are intercepted and replaced with the JSPs. These JSPs can be customized although industry experience has shown that customization can be problematic, especially when new users (such as a customer, manufacturer rep or vendor) are now accessing the data. What works well for internal use is not always appropriate to external users. That is why consideration should be given to determine if the application is suitable for conversion to extranet or public Internet usage or if the primary purpose is to GUI enable an application for internal end users to move away from the green screen look and feel. Often times, this is not appropriate because the application may require an IBM iSeries userid and other resources not suitable for external use. It should be noted that WOW can seamlessly interact with a WebFaced application. In this scenario, users may Webface some existing screens for internal use and develop new interfaces for external users with WOW, thereby integrating both solutions.

When we look at the primary purpose of HATS, it is very similar to WebFacing in that 5250 (green) screens are converted to HTML; however, the conversion happens at runtime, not as a development step. Many of the issues with WebFacing also exist with HATS. WOW can interact with HATS applications in the same manner as WebFacing applications.

Usage Scenarios

If you have hundreds of existing screens that can be served "as-is", so that you can give applications a “PC” look and feel, WebFacing or HATS would be a primary consideration, given their ability to quickly convert these screens to a new format. You can also add new features or features requiring advanced customization with HATS, however we feel that this can be accomplished more quickly and efficiently with the WOW tool.

Often customers need to add totally new functions or an interface to an existing system for Internet access, such as allowing customer access to invoices, orders, shipments, etc. This is where WOW excels since it can easily create these applications while integrating with existing files. WOW can interact with RPG or COBOL logic, data queues or any other custom iSeries resource.

The table below indicates some of the other ways in which the products differ.

FUNCTION	WOW	HATS
Runs on WebSphere	Yes	Yes
Runs on Apache TomCat	Yes	No
Requires WAS App Development Server	No	Likely
Requires WAS Portal Server	No	Maybe
Rational Development Platform	No	Maybe
Portal Capability	Yes	Additional products required
Security	SSL and others	SSL
Single sign-on capability	Yes	Yes
Data validation lists	Yes	Yes

Summary

In summary, iSeries shops with many years invested in programs written in legacy code may benefit from the integration of both a web facing tool as well as WOW. Others may require that a few applications be developed to meet specific customer or vendor needs and choose to develop these applications quickly, using the WOW product. In any event, extending applications or producing new features is not something that can be easily accomplished using HATS or other conversion tools; it’s just not the primary purpose that they were designed for.