[mapserver-users] RE: Dynamically draw different sized ellipses on map

[christopher.schmidt at nokia.com]

On Sep 9, 2010, at 4:26 PM, ext stoli wrote:

> 
> 
> To better understand what I am doing, consider this as an example (perhaps
> not very realistic, but close enough):
> 
> Let’s assume you have a site that allows the user to analyze cell phone
> coverage. Your database has the location of all the towers. Each tower
> contains various antenna types, each antenna type with a different range.
> Occasionally, new towers are added to the database, old towers are removed,
> and antenna types are changed. The user selects the antenna type, submits
> the request to the server, and the server generates the ellipses that
> represent each antenna’s coverage. Those ellipses are overlaid on the map
> and the image is returned to the user. 
> 
> The map image processing is all done server side via cgi requests. Sounds
> like the best way to do this might be to write out a unique shapefile for
> each user session. Certain user inputs (like a change in antenna type) will
> require their shapefile to be updated (rewritten), while other inputs (like
> zooming, panning, etc.)  will not.

If you can generate the features on the server side, you don't need a shapefile,
I don't think. Just transform the data into GeoJSON features, and deliver them
to the client. The client will maintain these features until they close their 
page/navigate away.

I have been limited on internet access, so I have missed some earlier emails, 
but if you are just generating shapes on the server, loading them in the map
is just as simple as turning them into vector features that you can read and reading
them in the client.

-- Chris