[ka-Map-users] Dynamic points on the map, can you help please?

[Daniel.Huber at ch2m.com]

> -----Original Message-----
> From: ka-map-users-bounces at lists.maptools.org 
> [mailto:ka-map-users-bounces at lists.maptools.org] On Behalf Of The Bun
> Sent: Wednesday, October 17, 2007 3:11 AM
> To: ka-map-users at lists.maptools.org
> Subject: RE: [ka-Map-users] Dynamic points on the map, can 
> you help please?
> 
> 
> Hi Daniel
> 
> Again my reply is not passed for some reason. Anyway I sorted 
> out the server side dynamic points, in a similar way as you 
> suggested, starting with a layer with no connection in the 
> mapfile, I failed to have something fully dynamic ( ie 
> creating a layer on the fly ) but it is OK.
> 
> 
> 
> >  I used this approach and it works well, except I had to figure out 
> > how  to make mine dynamic for each user, since they did not want 
> > anybody else  seeing their data.
> > 
> 
> Well, I have the same problem, each user may have ( and see ) 
> different points and the map. I thought of two solutions: One 
> is to adapt the server side to cache tiles for sessions 
> instead for application but this may compromise performances, 
> server space and add complexity. The other one is adding 
> client side objects ( as you suggested in the other post ) 
> and implement everything in JavaScript, yes, because I don't 
> only have to mashup data I also need to query my dynamic data 
> ( by clicking on the points for example ) and showing extra 
> text information, I mean I may need to expand kamap class 
> storing coordinates and texts and need to implement something 
> clever in order to show the text related to a point when the 
> user click on the point itself. I really don't know which 
> direction to take .... what do you think?
> 
> Anyway the discussion is open and I'd really appreciate any 
> contribution.=)
> 
> Kind Regards
> Rosario


Rosario,

I've not had a need to interact with the data on the map so I don't know
the "best" method for querying the dynamic points in ka-Map.  Hopefully
others will chime in for that need.


While I'm sure there are simpler methods for creating dynamic data
layers, this is what I ended up doing.


1.  Generate a new mapfile using the a unique name.
	Info on unique names found here:
http://us3.php.net/manual/fi/function.rand.php#74351

2.  Set the path to that mapfile to a PHP session variable

	$_SESSION['mapFile'] = 'path.name.of.mapFile';


3.  Modify the "config.php" to always point to the new mapfile if it is
set.

	if ($_SESSION['mapFile']) {
		$aszMapFiles['dynamic']['path'] = $_SESSION['mapFile'];
	}


To ensure my dynamic layers were not cached, I set the following
METADATA tag for the layers in the mapfile:  "tile_source" "nocache"

Hopefully this is enough to get you going, although I'm sure I left off
some key points as I haven't messed with this code in 3 months.


Good luck!


Daniel