[Qgis-user] retrieve the Legend from wms using the SCALE parameter

[Andrea Peri]

Hi,
I notice that in qgis 2.18 and also in qgis 3.0
is not possible to retrieve the legend from the wms layer (using of course
the getLegendGraphic comand) apply-ing the SCALE parameter.

SCALE parameter is a STANDARD OGC parameter (optional) to retrieve the
legend
at the actual scale

QGIS allow to retrieve the legend using the the CONTEXTUAL option.
But it is anot standard parameter.
The contextual is of course more powerful but is a not standard and so not
always all the wms support it.

So' actually the only option is the standard getlegendgraphics that
retrieve without the scale parameter.

This some time give wrong lgends.

I report two eample.

The first is a good legend retrieved using the SCALE parameter from a wms
layer.

The second is a good example of what mean "sometime" retrieve the legend
without the scale parameter.

The second example repeat three time the same domain because there are
three different rendering at three scale interval.
Without the scale parameter the wms send ALL the legend for EVERY scale
interval.

The first example instead using the sCALE parameter obtain the right legend
for the scale of the MAP.

A.

-- 
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Andrea Peri
. . . . . . . . .
qwerty àèìòù
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