[Rspatial-devel] rgeos exportClasses SpatialLinesNULL

[Roger Bivand]

On Mon, 9 Mar 2015, Edzer Pebesma wrote:

> A package that imports (anything from) rgeos and declares
>
> MyClass1 <- setClass('MyClass1', contains = c('SpatialLines'))
> MyClass2 <- setClass('MyClass2', contains = c('MyClass1'))
>
> keeps getting the warning: "Found the following significant warnings:
>  Warning: class "SpatialLinesNULL" is defined (with package slot
> ‘rgeos’) but no metadata object found to revise subclass
> information---not exported?  Making a copy in package ‘minweSpatialNULL’"
>
> See
> http://stackoverflow.com/questions/28871632/how-to-resolve-warning-messages-metadata-object-not-found-spatiallinesnull-cla
>
> I don't understand why this is, but so do I not understand ClassUnions.
> I'm resolving this by having rgeos exportClass SpatialLinesNULL and all
> the other *NULL classes. (Having it not exportClass SpatialCollections
> did not resolve the problem either).
>

OK. I did a good deal to remove all the empty geometries in rgeos, mostly 
to get RNilValue back when empty instead of an empty Spatial*. There are 
arguments for having empty geometries too, but they create other issues, 
as they are valid but fail on lots of operations.

Roger

-- 
Roger Bivand
Department of Economics, Norwegian School of Economics,
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