Viságe is the latest
descendant of a project that stamina
software
started in 1994. The initial goal of the Viságe project was to produce
an intelligent terminal emulation product that would allow us to create
graphical interface widgets under the control of our multi-valued
programs.
As our
applications were developed with the our own 4GL tools, our intention
was to have a single code base that would be able to support both our
traditional terminal users, as well as a new class of user that would
use a PC and interact with our software via a Graphical User Interface.
We had a number of
false starts and setbacks over the next few years, and learnt a lot
about techniques and technologies that didn't work. We had moved from
the world of 16-bit Windows 3.11 to the allure of 32-bit computing under
Windows 95, and migrated from the sluggish world of interpretive Visual
Basic to the speed and grace of the Borland Delphi environment.
Eventually we did
get a version of this product operating, but it never saw the light of
day outside of our development facility. Whilst it performed as
specified, and allowed us to control the creation of Windows interface
widgets, the resultant applications were obviously not REAL Windows
programs.
Using today's
terminology we had created a type of hybrid screen scraper technology
that was doomed to fail, because by limiting ourselves to our 80 x 24
green screen heritage we had fallen well short of realizing the full
potential of the PC phenomenon.
We entered a
tumultuous period that resulted in a number of hard decisions being
made, and also saw us adopt a somewhat radical stance in terms of
technology.
Undoubtedly the
hardest decision that we made was abandoning the notion of supporting
green screens indefinitely into the future. It was obvious that in order
for us to be able to create solutions that could effectively compete in
the mainstream we could not be confined by the screen limitations of our
past heritage.
We also decided
that rather than developing our own proprietary mechanism for creating
screens we should look at adopting the new HTML 3.2 recommendations that
were at the RFC (and there were also some early papers about a subset of
SGML - this was later to become XML).
At this time
Microsoft had released Internet Explorer 3.0, and anyone who had heard
of HTML probably associated it with a printer, or if they were in the
know with slow connections to the Internet.
The target
environment we were looking at would see us deploy HTML over a high
speed (10Mbps at that time) LAN rather than the Internet, so speed was
not a major consideration, and the possibility of using script in the
browser for client side processing and customization was a BIG
attraction.
However, we now
had to develop middleware that could talk to a browser, multi-valued
host routines for handling communications and ticklish issues like the
management of state, and also re-work techniques that would enable us to
perform as much processing as possible on the client workstation.
We used code and
techniques from a multitude of weird and seemingly unrelated interface
projects we had done over the years, like document scanners, radio
frequency portable data entry units, real time data collection from
analogue and digital devices, and of course the core Viságe project
itself up until that time.
Initially we
developed a tool set that could be used with any web development tool
via the clipboard, enabling us to create database aware HTML and Script
there we could then paste into products like Visual Studio from
Microsoft, Dreamweaver from a Macromedia etc.
Our dream was that
we would be able to create a plug-in for one of these tools that would
allow us to extend the in-built Property Editor for standard HTML
elements to cater for the extended properties that we believed were
necessary to support the techniques we had developed, as the select and
paste mechanism we were using was too clumsy for serious development.
Eventually it
became obvious that the only way forward was for us to take the plunge
and develop our own custom Integrated Design Environment that was
conscious of the Application Development Framework (ADF) we had a
created for our own system redevelopment.
This concept has
matured from a simple idea to become reality, and today finds form as
the feature rich, multi-valued database aware Viságe.Designer.
Against this
background we can look at some of the simplifying assumptions that we
made along the way and are now implicit within the Viságe.ADF