Add Geographic Attribute(s) to Factlet (req. Geographic Data Type in Domain Model)

[rgrp]

As A

Developer

I want to

Add geographic (locational) attributes to Factlets.

Details

To implement this will require either:

• Storing simple strings which are then 'parsed'/manipulated outside of the DOM.
  • Could get away with this if we are pushing straight through the DM to (e.g.) Google Maps.
  • However this has the disadvantage that the geo data is essentially opaque to use at the DM level which makes things like querying difficult ...
• Use geotypes and then create a specific sqlalchemy type as detailed in  http://blog.bycycle.org/2007/01/29/using-postgis-with-sqlalchemy/

[rgrp]

Looks like we really want to use/integrate with these two parts of PCL:

•  Shapely
•  GeoJSON

In particular we need to connect Shapely objects to sqlalchemy. Examples of how to do this (Unfortunately the bycyle.org code no longer seems available with trac link leading to a page saying this website is coming soon).

•  http://sgillies.net/blog/531/the-shapely-alchemist/ -- from author of PCL!
•  http://trac.mapfish.org/trac/mapfish/browser/trunk/MapFish/server/python/mapfish -- not fully explored (+ GPL'd)

[rgrp]

See r131.