How to index...

joerg

Hi,

I'm trying to figure a way to index pages of an entire website in a database, but can't find an (elegant) way to do so.
The problem is similar to a book. Let's say, you have several chapters, those chapters are seperated into subjects, and those subjects are broken into single pages. I need to be able to show the content page of each chapter and subject, as well as a general TOC. The TOC would somewhat look like this:
1. Chapter 1
1.1 Subject 1.x
1.1.1 Page 1.x.x
2. Chapter 2
... and so on. No problem, index them sequentially... only I need to be able to insert a page (or subject or chapter) somewhere in between, so the position in my TOC changes for all following pages.
I figured using a position index for each chapter and subject would be the solution, with an index that increments at least by 100. If I want to add a page between 0 and 100, I use the middle (=50) as an index, and my TOC shows the new page between the 0 and the 100. This only works for so and so long.
To make it worse, I'd like to have some pages that are not shown in the TOC, instead they should be reachable from the indexed page with 'next' or 'prev', for articles that are too long to put into a single page.

Has anyone an idea on how to solve this problem? Does PHPNuke or similar content management systems index in a similar manner, and how?

Appreciate your help,

Joerg

Anon

What you probably want to do is build a "linked list" out of your records. If you give each record a link to the previous record then all you need to do is change 1 record when you want to insert a new one.

So if you have 3 records each one would be linked to the one infront of it and the first on would have no link:

1: no link
2: linked to 1
3: linked to 2

Now if you want to add a record to the end that's easy you just grab your largest record and then add the new one linking it to that one:

1: no link
2: linked to 1
3: linked to 2
4: linked to 3

No if you need to add a record inbetween 2 and 3 you need to know that this record comes before #3 (since you don't know what comes after any given record in this scheme), and then you find out what record 3 is linked to and when you add 5 you make it linked to 3's link and then link 3 to 5:

1: no link
2: linked to 1
3: linked to 5
4: linked to 3
5: linked to 2

Now you've inserted your record inbetween the 2. If you need to you can change this to be "prev" and "next" links then you'd need to change both record 2 and 3 in the above example but you'd be able to move forward and backwards a little easier. Although calling the record that is linked to your current record makes for an easy next link.