[fusion-users] MapServer Legend Render & Multiple Maps
Tim.Nolte at ipcswirelessinc.com
Thu Oct 29 10:09:17 EDT 2009
As I've been working to setup the desired setup I've noticed that there
are quite a few issues with how the Legend renders and the maps get
layered. The setup I am trying to get working is using multiple "<Map>"
definitions in a single "<MapGroup>" for the purpose of having different
layer groups rendered as stacked transparent PNGs. This gives the end
user the perceived performance boost. (Each transparent PNG is generated
and loaded and then stacked in the right order. The end-user see
progress of the map layers being built up.) The issue with doing it this
way is the fact that the Legend render really isn't designed to setup
this situation. First problem is that the legend layers seem to be in a
backwards order (top visible layer is at the bottom of the legend list).
The second problem is that turning off the "Root Folder" and/or "Map
Folder" breaks the output of the legend. Someone submitted the start of
a fix for the second problem but things still don't render in the legend
properly and in many cases the legend icons aren't rendering either,
which is a third problem.
One of the hard things about rendering the Legend for MapServer layers
is the fact that MapServer allows such flexibility in how you define
layers: they are a part of a group or not; have 1 or more CLASSes; the
CLASS is named or not; layer is ON/OFF by default; MINSCALE/MAXSCALE for
layer and/or CLASS. All of these scenarios need to be accounted for in
the Legend rendering. I'm more than happy to help develop the code, but
I have a hard time updating when I have no ability to take part in
submitting code changes to the SVN. This causes me to have to do a DIFF
on every file when there are code changes so as not to lose my custom
code, also I have to make sure that my custom code doesn't get broken
updating stuff developed by others who don't have my custom code
Another problem of the multiple MapServer "<Map>" definitions is that
the actual map images (each in their own DIV) is not getting the correct
z-index so that the layers are stacked in the right order.
Is anyone actively working on the Legend rendering? What are the
limitations with the Legend rendering when taking into consideration
both MapServer and MapGuide? Am I better off switching over to MapGuide
if I'm going to use Fusion? Does anyone have any fixes for my issues?
Timothy J Nolte - tnolte at ilpcs.com
Network Planning Engineer
iPCS Wireless, Inc.
4717 Broadmoor Ave, Suite G
Kentwood, MI 49512
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