[Potlatch-dev] Vector layers from config file

[Andy Allan]

Hi Devs,

I've started work on specifying vector background layers from config
files - only BugLoader and BikeShopLoader are supported at the moment,
but it'll be easy to expand it to cover the other loaders like tomH's
new KML loader.

I'd like to populate the VectorBackground dialog with things that the
server admin believes will be useful - for example, a list of KML
files, a bugs layer etc - without necessarily loading them all during
startup. At the moment that needs a bit of a rethink, since VBs can be
either visible or not visible with the toggle, but there isn't really
the concept of "configured but not loaded" layers. Most loaders only
create the layer as part of loading it, which triggers policyfile
loading etc.

Is this something reasonable to aim for? I don't want to get to far
down the line and find that i've not thought it through. I'm thinking
VBs should be in one of three states
a) configured (i.e. available in the dialog for loading) <- new
b) loaded
c) loaded but hidden

Are there other states?

Also, I'm aiming that VBs should have various loading profiles. So far
we've got three types:

1) one-shot (e.g. a kml file)
2) update-on-pan (e.g. the bugs layers)
3) "multi-shot" (e.g. the TrackLoader) where hitting download
repeatedly in the same place gets you different pages of results.

Are there other modes? What about the Importers all working with
arrays of files?

Anyway, thoughts welcome, especially the "whoa there, you're missing
the obvious" variety.

Cheers,
Andy