Multi-Tiered Navigation

ben_c

Well, I'm finally at my wits end. I've been trying my hand at writing this for 2 months now, and I am desperately seeking help.

I'm trying to build a dynamic side-navigation bar utilizing php and mysql. The first level of navigation will always be displayed, and if a link on that first level is clicked, it will then display possible 'children' underneath, and when those children are clicked, possible /other/ children will be displayed underneath that one. So on, and so on.

Are there ANY already written snippets of code that do just this, or does anyone here have any idea on how to do this? I think my database structure is efficient, but I'm probably very wrong as trying to explain it to someone ends up with me wanting to pull my hair out.

Here is the structure as it is, now.

id | link | name | parent_id | child_id

id is unique and auto_increment
link is normally blank unless specified
name is the name of the link
parent_id is filled if it's a child, and parent_id would be the 'id' that it belongs to. if it's 0, then thats the first level of navigation.
child_id is filled if there is a child underneath the parent. default is 0.

hopefully nobody reads this and closes their browser in frustration from reading this. i'm just as frustrated. 🙁

Thanks!

cordex

chuckle What is this? My alter-ego?

Don't worry son, I carry messages from the future. You will prevail.

To assist you (myself?), allow me to suggest a couple of things. When I did this, I decided to send an array (urlencode()ed, of course) of open sections. I used two main recursive functions: one to print all the open children stored in the array and one to destroy the open children of a closed thread.

-The one and only true Ben

ben_c

Good idea.

But what variables did you send to the browser to tell PHP what tier you clicked on?

-The other Ben

cordex

I sent two variables.

$item = the autoid of the object clicked upon
$open = an array of open objects

if $item is in $open, you are closing an object and have to kill the children. (as brutal as it sounds, it is completely necessary).

if $item is not in $open, you add it to $open

after those two checks, you run your print function which prints first the top level values, checking each one to see if it exists in $open. if it does, it calls the print function with a variable telling it to display the children of the open object. it checks each child to see if they exist in $open and if they do .... etc, etc
if the object does not exist in $open, it moves on to the next, prints it and checks it against $open. To quote Vonnegut:
And so on.

-Alpha Ben

ben_c

Ok, let me scribble my brainwaves here. Everything that's being displayed in the browser is part of the $open array, right? That said, then $item will always be in $open?

Also, what did your database structure look like? Was it similar to mine? If you wish to contact me privately so as not to advertise your code, that's fine. er, and if you don't want to tell me, that's fine too. 🙂

Gahh.. this is so confusing although it's such a simple idea. <rant>Why oh WHY DO CLIENTS REALLY NEED THIS SORT OF NAVIGATION!?! If they have that many links on their damn site, they will never be clicked nor understood by Joe User.</rant>

Thanks for the push in a good direction, btw.

-Bizarro Ben

cordex

One more thing. I looked back at your database and you've got at least one unneeded field. You only need to determine the parents - the children can be extrapolated from the code.
- Alpha B

ben_c

excellent, thanks!

[deleted]

Don't you just love a forum where users can have the same name? :-)

cordex

My table had a bunch more fields to allow for more versitile menu structure (open icon, close icon, font size, font color etc) but basic functionality is accomplished by this:

autoid | entry | url | parent

with regards to the presence of $item in $open:
if you read through my post again, hopefully, you'll notice that $item is not placed in $open unless it is not already in there. Think of $item as a trigger, not as a result. $open is the result.

$open is the list of currently open objects, so if you click on an unopened object, $item will contain the autoid of that UNOPENED object but will be added to $open. If $open contains $item, then that object is already expanded and you need to send $item to the function to close all children (my function that deleted all the children/subchildren/subsubchildren/etc/etc was called "infanticide")

Don't beat yourself up over this too much. My boss (rated hardware/networking/software/programming/electronics God Level 10+) wrote an original script for this that had some severe bugs. Took me a week or two to iron out myself. My "ironing" process basically involved a complete re-write. Don't be afraid to start over.

I'd post my code, but it technically doesn't belong to me anymore.

-Bennish (of or relating to Ben)

cordex

huh? oh, I see the confusion. No vincent, I just set up two profiles, telecommuted between two computers, took a picture of some poor college bozo and have been talking to myself all day. I think I really helped myself out, didn't I? grin
Actually, I prefer forums like http://www.hvt-automation.nl/yapf where users are uniquely identified and can submit articles on commonly asked questions. (shameless plug for Vincent's PHP forum).

Hey Ben, go there.

-Ben which one am I again?

ben_c

actually i dropped out of college because i thought that back in 1997, working was more important! sigh how i ponder the days of a job-free college life.

cordex

Who's has a "job free college life"???? Those lazy miscreants ... I'll KILL 'em!

-Ben

ps let me know how your navigation turns out, Ben.