Expose method of finding the name of longitude, latitude and time axes of a CSML feature

[spascoe]

An WMS will need to deduce which components of a feature's domain are longitude, latitude, time, etc. without drilling down into the depths of the CSML object heirarchy.

We also need to have access to the units of measure of a domain axis. This is required for WMS (Layer/Dimension?@units), although could be left blank as a fudge.

[domlowe]

Have defined 4 new methods:

feature.getLongitudeAxis()
feature.getLatitudeAxis()
feature.getTimeAxis()
feature.getDomainUnits()

The first three return either the name of the axis, or 'None'.

The fourth method should return a dictionary of the form: {axisname:unit}. Except it currently just returns 'None' because units aren't currently defined in the stub CRS catalogue - this is part of a wider issue about defining CRSs generally - see 407. I have just currently defined quite loose CRSs in the catalogue stub at the moment.

For now (Beta) I think we need to work around this until we've had a more complete discussion of CRSs in NDG. If necessary we may need to look at Coapec and DDC data and define specific CRSs (with units) in the stub catalogue for those datasets.

Closing this ticket as the code is there now - even if the CRSs aren't.

[spascoe]

I don't see this change in the SVN. Could we only close tickets once a solution has been commited.

Thanks, Stephen.

[domlowe]

We forgot to commit it... :-)