[ka-Map-users] ka-Map and OpenLayers

Paul Spencer pspencer at dmsolutions.ca
Tue Jun 20 15:56:05 EDT 2006

 From my initial review of the code base and project objectives, I  
feel that it offers a cleaner code base and architecture.  It is more- 
or-less what I would do with the ka-Map code base if I wrote it.

The differences are more in the project objectives.  One of these is  
to be able to integrate Google, VirtualEarth, Yahoo and other  
commercial/free tiles without violating their terms of use.  The end  
result is that the application adapts to the limitations of an  
existing set of tiles (tile sizes, projection etc).  It is then  
possible to build overlays that morph based on the underlying layer  
source.  I'm not sure this is a big priority for me, but it does make  
the API itself more compelling I think.

I'm not sure that I have described this very well.  Perhaps John  
could explain this concept better (since he was the one who explained  
it to me :))

John and I agreed that the projects should merge.  He/OpenLayers are  
willing to start from ka-Map and integrate the OpenLayers stuff if  
necessary.  I just feel that it would be easier to move the ka-Map  
code into OpenLayers rather than the other way around.

One big disadavantage to the ka-Map community is that the API will  
change.  We may be able to provide a compatibility API but I think  
that would be more work than it would to help people convert their apps.

Perhaps a reasonable compromise would be to develop a Google API  
clone (something I have been against previously), which could make  
OpenLayers a compelling environment for existing Google-hackers plus  
give them the option to move from Google in the future if the terms  
of use/ads become cumbersome?



On 20-Jun-06, at 3:15 PM, Steve Lime wrote:

> What does OpenLayers offer that ka-map doesn't ( besides a better  
> name ;-) )? The
> list you reel off of limitations is pretty substantial.
> Steve
>>>> Paul Spencer <pspencer at dmsolutions.ca> 6/20/2006 1:28:19 PM >>>
> Hello ka-Mappers!
> I had a very interesting discussion with the developers of
> OpenLayers, a javascript api for tiled maps.  Turns out OpenLayers
> and ka-Map are very similar.  We decided that it would be beneficial
> for both communities if we attempted to merge the projects.  The
> purpose of this email is to present this idea to the ka-Map community
> in order to generate some discussion on the subject.
> OpenLayers is hosted at http://www.openlayers.org/.  They have some
> very interesting objectives which I think are compatible with ka-
> Map.  Take a look at their site.
> OpenLayers is written on top of prototype.js, which was one of the
> things I was planning to do with ka-Map in the next couple of weeks.
> It has a very nice looking architecture and the code base is very
> readable.
> It is lacking quite a few things that ka-Map has:
> * core tiling engine is very similar, but it is not quite as optimal
> (doesn't reuse images for instance)
> * overlay stuff is point/text only
> * lacking tools (layer controls, scale bar etc) and the windowing  
> stuff
> * lacking query capability
> * tile caching
> * probably several other things I can't think of right now
> I think that there are some differences in how OpenLayers and ka-Map
> approach things, but I'm not entirely sure that they are significant.
> At this point, I am proposing to join the two projects into a single
> project.  My desired approach would be to start with the OpenLayers
> code and start to bring over the parts of ka-Map that I(we) feel are
> missing.
> Please let me know what you think of this.  And point out all the
> problems you can think of.
> Cheers
> Paul
> +-----------------------------------------------------------------+
> |Paul Spencer                           pspencer at dmsolutions.ca   |
> +-----------------------------------------------------------------+
> |Applications & Software Development                              |
> |DM Solutions Group Inc                 http://www.dmsolutions.ca/|
> +-----------------------------------------------------------------+
> _______________________________________________
> ka-Map-users mailing list
> ka-Map-users at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/ka-map-users

|Paul Spencer                           pspencer at dmsolutions.ca   |
|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|

More information about the ka-Map-users mailing list