A three layered approach that separates the data, the Model, and the view. The data is the database the model contains any business logic and the view displays it all. The three parts are designed so that any on part can be totally replaced without the other two knowing that the one was changed. It came about in a language called smalltalk and is being revived by the Java Swing componenets.
Thanks Marc Aylesworth C3I Associates AFRL/IFSE Joint Battlespace Infosphere Team 525 Brooks Rd Rome, NY 13441-4505 Tel:315.330.2422 Fax:315.330.7009 Email: [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Cameron Schlehuber Sent: Wednesday, April 20, 2005 7:47 PM To: hardhats-members@lists.sourceforge.net Subject: RE: [Hardhats-members] Configurability of fields in FileMan While looking forward to Richard's response, let me chime in here with some primitive examples of efforts along the lines of "business rules & engine" in VistA and observations on where things might end up (those who know me well know that I'm a perpetual optimist!) One example is the ORDER DIALOG file 101.41. It was designed with the intent of being able to script very complex dialogs for placing orders. The rules of prompt/user response/prompt carries the templates of VA FileMan to a higher level of abstraction and functionality. The new capabilities in CLINICAL REMINDERS v 2.0 are likewise based on rules that can be built and exchanged between users without having to write M routines. These are special cases that have been justified due to user demands. What is missing is the next level ... a generalized rules engine that could support ANY service or application. The down-side to date is the holding back of the creation of a good (not perfect, good!) rules engine. In large part due to the belief that rules engines are "too difficult to build" or "don't work well in the general case". A few fortunate circumstances are coming together now though. One is that the VA's Enterprise Architecture appears (to me at least) to be poised to aggressively explore true rules engines and actually get down to doing some real implementations. Another circumstance is a prototype effort to mine a couple of VistA applications for their rules and build a database of them (using some new OMG draft specifications for such representations and models) such that the rules can be modified at the business representation layer and forward engineered into running applications. I believe these are sufficiently low cost efforts for now that they can afford to "make mistakes" and risk reaching for something potentially very productive. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Self Sent: Wednesday, April 20, 2005 4:29 PM To: hardhats-members@lists.sourceforge.net Subject: Re: [Hardhats-members] Configurability of fields in FileMan Richard Davis wrote: >Today, the core database within VistA does not contain a generalized >"business-rule" engine as a centralized, high level, tabled driven module >that controls all data storage and retrieval. Classical DHCP applications >and the VistA modules of today are obliged to embed their business rules in >M(UMPS) routines where they are extremely difficult to manage. > >No amount of "open" design in DHCP/VistA can overcome this shortcoming of >the missing business rule engine. Please give more description and some examples of what you think is missing and how it might be added. --------------------------------------- Jim Self Systems Architect, Lead Developer VMTH Computer Services, UC Davis (http://www.vmth.ucdavis.edu/us/jaself) ------------------------------------------------------- This SF.Net email is sponsored by: New Crystal Reports XI. Version 11 adds new functionality designed to reduce time involved in creating, integrating, and deploying reporting solutions. Free runtime info, new features, or free trial, at: http://www.businessobjects.com/devxi/728 _______________________________________________ Hardhats-members mailing list Hardhats-members@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hardhats-members ------------------------------------------------------- This SF.Net email is sponsored by: New Crystal Reports XI. Version 11 adds new functionality designed to reduce time involved in creating, integrating, and deploying reporting solutions. Free runtime info, new features, or free trial, at: http://www.businessobjects.com/devxi/728 _______________________________________________ Hardhats-members mailing list Hardhats-members@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hardhats-members ------------------------------------------------------- This SF.Net email is sponsored by: New Crystal Reports XI. Version 11 adds new functionality designed to reduce time involved in creating, integrating, and deploying reporting solutions. Free runtime info, new features, or free trial, at: http://www.businessobjects.com/devxi/728 _______________________________________________ Hardhats-members mailing list Hardhats-members@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hardhats-members
