[Fwd: Re: [UMN_MAPSERVER-DEV] single classed layers and GetLegendGraphic]

[Daniel Morissette]

Kralidis,Tom [Burlington] wrote:
>
> Bottom line is that, unless a layer has a classification associated with
> it, I don't think (at least from what I've seen in implementations) that
> text is needed, as this (usually) is taken on by a client who would
> (presumably and commonly seen in implementations) print out
> <Layer><Title> information along side the legend icon, as part of, say,
> an HTML TABLE construct.
>

As I wrote already, I agree that this may be a valid interpretation, and
that was our initial interpretation of the spec. However the spec is
vague on this and in bug 653 it was requested that we align MapServer's
behavior with other (prior) implementations (cubeserv) so that clients
can better interoperate.

What we did is fully predictable and is decribed in bug 653 comment #1:
http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=653#c1

I don't think we should change the behavior of GetLegendGraphic again at
this point until either (1) the spec is clarified, or (2) we find
several reference implementations that used another interpretation that
is at least as predictable as the one used by Cubeserv and MapServer.

>
> Hence the "GetLegend" request, in which a client can be guaranteed to
> get at least the layer title text if the layer is not classified.
> GetLegendGraphic will (should?) only return text if the layer is
> classified.
>

I'm not sure to follow this specific comment, but I think our current
"GetLegendGraphic with no RULE" behavior described at the URL above is
pretty much what you would like GetLegend to be based on your other
comments.

If I understood correctly, the only change that may be required is that
when no rule is specified you would like to get the layer title in an
image if a layer has no class (instead of nothing as would happen now).
This would be a much simpler fix to your problems than messing around
with a new vendor-specific GetLegend request.

Daniel
--
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  Daniel Morissette               dmorissette at dmsolutions.ca
  DM Solutions Group              http://www.dmsolutions.ca/
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