This technical note introduces the 4D News Jockey example database. This database includes many features, but in particular it highlights what can be accomplished with optimized text parsing techniques that work with BLOBs.
Why use BLOBs for text parsing?
One of the main benefits of text parsing in BLOBs is that it enables you to get past the 32,000-character limit of 4D text fields. Suppose you're creating a web application. You can start with some basic text, then you add some HTML to it, and pretty soon it can grow past 32,000 characters. And when that happens, you need to start handling your text in BLOBs.
There are some text-parsing techniques you can use that will help you realize substantial performance gains. And if you're going to start writing your own text parsing code, you might as well write it so it works with BLOBs, so you can handle larger blocks of text.
Some of the main applications where you can apply these techniques are:
Heavy-duty web serving applications
General text parsing
Implementing a TCP protocol
That last item brings us to the "4D News Jockey" example database that accompanies this technical note. This is a project that I had wanted to do for a long time. I tried using shareware Usenet newsreaders, but I'd always end up finding things that I knew I could improve on if it was in 4D. When the 4D Internet Commands plug-in version 6.7 was released, it included some new features that made it possible to write my own newsreader, so I gave it a shot.
4D News Jockey includes many features, because being not only the designer, but also the end-user, anytime I found a feature I wanted, I was able to create it in 4D. There is much more to the example database than will be discussed in this technical note. A separate document that accompanies the example database includes comprehensive documentation of its features.
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