[ka-Map-users] Architectural questions.

Sacha Black sacha.black at gmail.com
Thu Nov 8 14:23:28 EST 2007

hi rosario,

i have experimented with openlayers... i'll try to explain why i still
chose kamap for one project.

my opinion is that openlayers is a better organized project in terms
of code and connectivity to other projects/services, so if you are
coming with a programmers background and need that kind of
connectivity that is great. but with openlayers you have to create all
of the application yourself. and that is time spent away from
delivering your actual map content if you know what i mean.

when i tested openlayers, i tested it using WMS to access data from a
mapserver... i found the results to be slow as compared to kamap, but
i know WMS is slow in general, and i don't think a cache was involved
so this is not a fair comparison. i had little success connecting open
layers directly to mapserver without WMS for some reason, and i didn't
have the time to figure out why due to deadlines.

more important for me, i found that open layers required specifying
layer attributes in the client (which duplicated settings in the map
file, sometimes over-riding), and that this made tracking errors in
rendering more difficult. these tests were just using a test map with
3-5 data layers. i can't imagine how hard this would have been with a
more complex mapfile. and most of my mapfiles are quite complex.

i come from a background of less programming, more traditional GIS,
cartography and mapserver. for me, ka-map is much easier to use
because ka-map really respects the content of the mapfile as far as
rendering the maps. ka-map thinks in "groups" exactly the way
mapserver does, while openlayers thinking is a bit different. neither
is right or wrong, but if you have a large background in mapserver,
kamap is a bit more intuitive.

i should say that i am serving my own data, as opposed to connecting
to services from places like google or microsoft, so this cartographic
control was  important to me.

when it comes down to it, i didn't need the flexibility that open
layers gives because i was strictly using my own data directly via
mapserver, and ka-map had the majority of the basic tools i needed to
deliver my content without a lot of extra work. i fully expect i will
have a good reason / opportunity to use openlayers in the future, it's
just that for this particular project, the issues above caused me to
stay with kamap.


On Nov 8, 2007 6:51 AM, The Bun <rosario.carbone at ipl.com> wrote:
> > On 7-Nov-07, at 7:34 AM, The Bun wrote:
> >> I think as "better" mainly the drawing speed: Panning, Zooming,
> >> caching etc.
> >> But "better" is also a rich and working client API as well. I may
> >> need more
> >> functionalities like for example, adding features, showing info
> >> windows,
> >> handling events on the map and the features, run searches
> >> on the layers etc.
> > Then OpenLayers is probably what you should be using.
> > Cheers
> > Paul
> > +-----------------------------------------------------------------+
> > |Paul Spencer                          pspencer at dmsolutions.ca    |
> > +-----------------------------------------------------------------+
> > |Chief Technology Officer                                         |
> > |DM Solutions Group Inc                http://www.dmsolutions.ca/ |
> > +-----------------------------------------------------------------+
> Hi Paul,
> I followed your suggestion and started to test OpenLayers. First thing I
> noticed was that there is no much documentation around, but this is a
> problem of all open sources and you need a lot of time to make your code
> running, fortunately at this stage I have some time for experiment so..... I
> also have been quite lucky as I could test my main base map (MapServer map)
> with OL that talks directly to MapServer via WMS, I didn't try with the CGI
> directly but I'll do.
> In your opinion, or anybody opinion, this is an open discussion, what are
> the advantages of using
> OpenLayers.Layer.MapServer instead of OpenLayers.Layer.WMS?
> My first impression with OL anyway is that seems quite slow and quite
> difficult to use as well. I also want to test with the interface of kaMap or
> TileCache and check how much the performances will improve.
> Finally, I am not pretty sure I am going to the decide for OpenLayers,
> because, and it is my impression, it seems to be aestetically very nice and
> with a rich API but more difficult to use and a bit unstable I may prefer
> carrying on with kaMap nevertheless the limitation of the API which
> potentially can be improved.
> What is your opinion?
> Regards
> Rosario
> --
> View this message in context: http://www.nabble.com/Architectural-questions.-tf4759229.html#a13648364
> Sent from the ka-map-users mailing list archive at Nabble.com.
> _______________________________________________
> ka-Map-users mailing list
> ka-Map-users at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/ka-map-users

More information about the ka-Map-users mailing list