[sword-devel] Why You Should Love SWORD 103 - What Is A Filters
Troy A. Griffitts
scribe at crosswire.org
Fri Dec 3 08:19:52 MST 2010
*The anatomy of an SWFilter*
At the most basic level, a SWORD filter performs some distinct and
concise transformation to the data stream.
The actual signature of a filter is very minimal, and looking at the
SWFilter interface itself...
... there is simply 1 method you need to implemented to create a filter:
const SWKey *key = 0,
const SWModule *module = 0) = 0;
Basically, you're sent a buffer of text, possibly along with some
context in the form of an SWKey and SWModule-- in case you care, and
then you make some small change to the buffer.
Easy, right? Well, sortof.
Anyone can write a filter. The great thing about filters is that they
partition up a very complicated task: processing a complex document,
into tiny manageable chunks that anyone can tackle.
"Handle <title> tags in a buffer? Sure, I can do that! That's easy....
Wait.... What should I _DO_ with a <title> tag?"
That's when the real world hits and things get more complex. A SWORD
filter is an easy to grasp, easy to code against, abstract concept.
How filters are orchestrated together inside the SWORD engine-- what
distinct roles they are expected to fill, when, and in what order-- is
hidden knowledge that for years only few have been privy to yield...
Stay tuned for "The Red Pill" coming soon to a listserv near you.
More information about the sword-devel