mapnik/mapnik — Issue #1044: Add mapnik::key_not_found exception for datasources
Author: springmeyer
Created: 2012-01-20 17:14:50+00:00
State: open

Currently if a mapnik::query is passed to a datasource requesting attributes that the datasource does not posess we through a mapnik::datasource_exception and try to form up a fancy string printing the available fields (otherwise this is quite difficult for users to debug).

But this is poor form - we should offer a new exception that calling applications can make sense of so that the calling application can catch and then query the available fields (avoiding having to form up the strings in c++ in each datasource).