Re: Re: Web-Facing and 5250 removal

Wow...very nice explanation...thanks.

On Tue, 11 May 2004 17:00:30 -0400, "Buck Calabro"
<buck.calabro@xxxxxxxxxxxx> said:
> > Web-Facing is simply a process of building/converting
> > a Graphical User Interface (GUI) on top of a
> > new or existing business application.
> 
> The term 'web-facing' and its ilk has been adopted by who knows how
> many people as a generic term meaning 'uses a web UI.'  This is all
> too often confused with the IBM product called WebFacing which is part
> of WDSCi.  It reads the DDS source and creates Java servlets and jsp
> pages for deployment on WAS or Tomcat.
> 
> JWalk is a screen scraper, which is a process of reading the 5250 data
> stream and interpreting the look & feel based on what it sees.
> Neither WebFacing nor JWalk change the underlying RPG programs which
> make up the application, but at least WebFacing uses industry standard
> Java to create its UI.
> 
> Why is this important?  With IBM's WebFacing, you can convert your
> application once, and re-use the converted components (JSP, servlets,
> classes) in your own design.  You've already deployed WAS and Apache
> and have literally all the infrastructure you need to add brand new
> servlets to the application.
> 
> With a screen scraper, you get none of that and you are 'locked in' to
> their solution.  You can't incrementally add to your existing deployed
> web code base because you haven't got any.  When you want to make a
> change, you must go back to the DDS and make your changes there.
> Modern screen scrapers all have some way to customise the look of a
> screen, which often means that once you've changed the DDS you have to
> revisit the 'customiser' and make the GUI panel look good again.
> 
> What to choose?  It all boils down to the reason you are contemplating
> a web UI.  If you don't want to pay for a leased line and want the new
> office in Guatemala to access your app via a browser, you have a
> different set of criteria and problems than if you are trying to use
> Java because it meshes with the corporate goal of interoperability
> with some other vendor's application, which in turn is a different
> problem than being an ISV who needs the cachet of a web based product
> in order to make sales.
> 
> In general, the screen scrapers are very easy to use and deploy, but
> they have quirks in their recognition engines which are 'customised'
> so the panels look good.  There's often a double maintenance penalty
> (DDS and customiser) but since everybody knows DDS already it isn't
> seen as that big a deal.  Scrapers often don't need source code, and
> handle IBM panels like WRKSPLF.
> 
> The re-facing crowd often require source, and often make changes to
> it.  Almost invariably, those changes can be reused to enhance the
> application in the future.  Because they use source, they don't have
> to make a guess about what the panel should look like, and thus have
> fewer glitches in the recognition engine.
> 
> If your company wants to go to the web in a real way (learn Java,
> learn web infrastructure, good change management) then choose one of
> the re-facing products (PSC or WebFacing come to mind).  If you aren't
> going to invest the effort in becoming web experts, then choose a
> scraper (JWalk, Newlook and I think aXes fall into this category.)
>   --buck
> 
> 
> 
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-- 
  
  michaelr_41@xxxxxxxxxxxxxx

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