[OpenLayers-Dev] Know of any offline datasets compatible with OpenLayers?

Christopher Schmidt crschmidt at metacarta.com
Thu Nov 22 16:35:21 EST 2007


On Thu, Nov 22, 2007 at 08:36:40PM +0000, Ian Mayo wrote:
> Hi all,
> I'm trying to put together an OpenLayers distribution that will run
> from without an internet connection.  I'm really pleased with the
> soon-to-be-released cached worldwind layer, but am interested in
> vectored data such as coastlines and country outlines.  I've looked &
> looked, but can't find anything in the OpenLayers functionality
> specifically gives me what I'm looking for, but there are the Vectored
> layers.
> 
> So, can anybody point me to datasets representing world coastlines or
> country outlines that are recorded in one of OpenLayers vector file
> dataset?

There is no way that OpenLayers can render even a very low resolution 
data set of country outlines for the whole world. Figure, as a guess,
about 100 features, max, and that's if they're relatively simple.
Complex vectors -- even simplified complex vectors -- are going to cause
browsers to hang, rather than render the data.

Totally offline data can be easy... if it is small or your storage is
big. Storing the top 7 levels of the vmap0 dataset as tiles 
is something like 200MB of data. Depending what you actually want to do,
this might be useful or not -- but I'm almost positive that it's going
to be more useful than trying to actually draw the world as a vector.

Regards,
-- 
Christopher Schmidt
MetaCarta



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