[UMN_MAPSERVER-USERS] MS RFC 22: Data adapter support

[Frank Warmerdam]

Tamas Szekeres wrote:
> Frank,
> 
> As thinking of the layer reference approach I would add some other
> points to my previous post to consider:

Tamas,

I'm not sure if I have responded to questions 1-4, perhaps I'm reading
this out of order.

> 5) How the reference to the original layer should be maintained inside
> the adaptor layer. Should we
> lookup the layer by name from the list of the map layers every time or
> store a direct reference of the
> layerObj structure. In the latter case how should we handle when the
> referenced layer is
> removed and the reference will become invalid.

I had been assuming keeping just the name, and looking it up each time
as the tileindex lookups work now.

> 6) How to handle the copyLayer of the adaptor layer. Should the
> referenced layer also be copied? What to do when the referenced layer
> is copied?

If we just copy the name, this should be straight forward.

> 7) I consider the name of the layer is not unique. Having the layer
> name as an identifier
> how should we handle if 2 layers exist with the same name?

Well, I don't know that we enforce uniqueness of layer names, but
currently this would also be a problem for tileindex layers.

> Sorry to make much of flood with my questions above, I really appreciate 
> your
> work (along with Steve) sparing no pains to deal with my problem.

I don't mean to suggest I have all the answers.  I am just hoping that
considering some different options we might be able to improve or
simplify the proposal.  Of course as originally stated your proposal is
pretty workable.  I'm not sure if you mean I'm sparing you no pain. :-)

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org