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OLGA Strikes Back

** OLGA.GIF here **

Can the mysterious ID4 help save the force? Mark Wherry investigates.....

Last issue we looked at a basic OLGA set-up to achieve object linking and I expect, by now, you're all as impressed as I am every time I see it in action. If you would like more of the same stand by for "inplace drawing". This allows the output from one program to be drawn in another programs workspace. Sounds interesting eh? But if you're wondering, what on earth you would use it for read on...
 ID4 You?

With ID4-OLGA (Inplace Drawing For OLGA) you can, for example, put a spreadsheet file for Texel onto a web page displayed in CAB. This process is called "embedding" and opens up huge potential, particularly for the internet, and other document related mediums.

Imagine you've created a document and want to include information normally maintained using a spreadsheet, maybe prices, maybe football results - any data which needs updating frequently. Normally you would have to edit the document directly or at best cut and paste the updated information manually. Using inplace drawing you could "embed" the required spreadsheet information into the document, then whenever the spreadsheet file was updated the document would automatically display the updated file. Ideal for reports of all kinds and web pages.

Impressive eh? It goes much further! Taking this concept a stage further documents such as reports and web pages could be made up from a variety of component files.
Graphics could be embedded from an packages such as STella or Kandinsky, tables, graphs and prices from a spreadsheet (Texel) and the other text from a text editor such as Everest or QED. The master document would no longer exist as a traditional stand alone document, but be largely component based, and generated 'on the fly' as and when required. The potential is huge!
However, there are limitations to the usefulness of ID4 at the moment. For example, if we embedded a Texel spreadsheet in CAB you would need to own both CAB and Texel and have enough memory to run them both concurrently. Obviously, not everyone is likely to own all the programs you've used to generate your master document so using ID4 to generate documents "on the fly", across the internet is impractical - unless compact freeware viewers were developed to display the data to ensure everyone can view the page correctly.

Clients and Servers
You will usually hear these two words when OLGA is being discussed. CAB could be a client application to display data from various server programs. These programs are called servers, because they are able to send files, or output data (to the clients). For example in the CAB/Texel relationship CAB would be the client, and Texel would be the server. It's as easy as falling off a log.....

Keep me informed
A new extension to the current OLGA release is notification. The problem with object linking, is that only files the user has selected may be monitored and used by that client. This is usually fine, but supposing you wanted the client to monitor all files of a particular type in use on the system. The answer, as you might have guessed, is
notification. When notification is used a client is informed when any changes have been made to files it handles and the user can decide whether the file should be linked into the current document.

Call The OLGAnisator!
** On Reader disk logo here **
Unfortunately, although the number of programs which support the OLGA protocol has expanded to include some of the most popular software there are still lots of programs which do not. To address this problem, Thomas 'STella' Künneth has written a program which bolts on OLGA awareness to non-OLGA programs. However, this does not include ID4-OLGA support. OLGAnisator includes English instructions and is available from Thomas Much's OLGA support pages (see boxout) and PD libraries.

Return of the OLGA?
The problem that faces any proposed standard such as OLGA is support. While the basic object linking has been widely accepted by programs such QED, Everest, Homepage Penguin, Papillon, Kandinsky, Jane, PixArt and others ID4-OLGA also needs widespread support before most users will make the effort to use it. However, with programs like CAB, Texel, ArtWorx and STella adopting its use the outlook is promising - especially if some compact viewer programs are developed.

** boxout **
Future OLGA
As I'm writing this an exciting extension to inplace drawing is under development called inplace activation. This will not only allow a program's output to be drawn within another document but also enable allow the program to be operated within another document. Imagine all your programs running within a web page!...

For up to date OLGA information, including a list of supporting applications, check out the OLGA support pages on the internet at:

** BC on **
URL: http://www.uni-karlsruhe.de/~Thomas.Much/OLGA
** BC off **
** end boxout **

** OLGA_HYP.GIF **
OLGA now has a full English ST-Guide hypertext so let's hope authors do their bit and support OLGA...