{"id":41,"date":"2011-05-11T22:28:17","date_gmt":"2011-05-11T21:28:17","guid":{"rendered":"http:\/\/muttznutz.net\/muttzblog\/?p=41"},"modified":"2011-06-07T00:07:21","modified_gmt":"2011-06-06T23:07:21","slug":"setting-them-up","status":"publish","type":"post","link":"https:\/\/muttznutz.net\/muttzblog\/post-processing\/setting-them-up","title":{"rendered":"Keyword Classes Pt.2 – Setting them up"},"content":{"rendered":"

In the first article<\/a>, I talked about image metadata, and identified the shortfalls in terms of what I need them to do …<\/p>\n

The third article<\/a> demonstrates how I’ve used these keywords to drive the content of my site. (It might be worth taking a look at that article if you don’t understand what I’m going on about<\/em>)<\/p>\n

I’ve called my solution “Keyword Classes”, but they could equally be referred to as “Structured Keywords” or “Smart Keywords”.<\/p>\n

This article talks about how I’ve made ’em work…<\/p>\n

Disclaimer<\/h3>\n

To really use these classes to best effect, you’ll need to be able to parse the entries using a programming tool. If you don’t know how to code – or don’t know someone that does – then I’m afraid you probably won’t be able to get this done.<\/p>\n

For those who want to read on anyway, I should explain the phrase “parse” – which (in programming terms) means splitting up a long string into its individual components, so that each can be processed separately.<\/p>\n

So parsing a keyword string that looks like [dn]204;[fi]Humphead wrasse[spf]Cheilinus undulatus<\/code> should give three entries:<\/p>\n

[dn]204
\n[fi]Humphead wrasse
\n[spf]Cheilinus undulatus<\/code><\/p>\n

This keyword string would be parsed by php as having two keywords – the semicolon in front of the [dn] would be the break point.<\/p>\n

Delimiting Class Identifiers<\/h3>\n

So that the programs reading the keywords can know 1) that it is a class item and 2) what type of class item it is, I needed to set up an identifier system.<\/p>\n

I figured the best way to do this is to start the keyword with a delimited string, containing a class identifier (stay with me – I’ll get to this in a minute). Separate start- and end-delimiter characters would work best, and they should ideally be characters which wouldn’t normally turn up in your keywords.<\/p>\n

Just to complicate things a bit more, certain delimiters have specific meanings for HTML (the language that drives browsers). These are often changed by scripting languages – or may behave unpredictably – so quote characters are out, as are the GT\/LT angle brackets (<>) Forward- and back-slashes are also out. If you want to geek out a bit, then you can check out the HTML Entities page<\/a> on the W3Schools website for more details.<\/p>\n

(For the techies : I did try to embed XML, but – apart from entity encoding – it got much too unwieldy trying to guarantee closing the entities).<\/em><\/p>\n

Ideally, the delimiter at the start of the string would be different from that at the end. The most natural fit is, therefore, either the square brackets ([]<\/strong>) or curly parentheses ({}<\/strong>). The former doesn’t need a shift key, so I’ve gone with those.<\/p>\n

Class Identifiers<\/h3>\n

Now we get to the heart of it. Each class of keyword needs a separate identifier. These can, actually, be of any length (but keeping it to two or three characters is probably more efficient). I like to use abbreviations that are easy to remember.<\/p>\n

So for my underwater albums :<\/p>\n