[pdal] PDAL Pipeline Extensibility

[Howard Butler]

> On Dec 30, 2016, at 3:42 PM, Howard Butler <howard at hobu.co> wrote:
> 
> After thinking about it a bit, my plan is to put everything in the kwargs dict of the function and simply call the function with it. This would allow you to set things like the stage metadata via this mechanism as well.

A followup to let you know this is now complete in master. A 'schema', 'metadata', and 'spatialreference' dict are now available to filters.programmable [1] and filters.predicate [2] Python filters. Additionally, you can modify/create inline metadata using this mechanism by updating the "global" metadata dict in your function. See the unreleased docs [3] for more detail.

Howard

[1] http://www.pdal.io/stages/filters.programmable.html
[2] http://www.pdal.io/stages/filters.predicate.html
[3] https://github.com/PDAL/PDAL/blob/master/doc/stages/filters.programmable.rst#module-globals