QGIS-Server wrong legend generation if scale parameter is present

[qgib]

Author Name: aperi2007 - (aperi2007 -)
Original Redmine Issue: 10470
Affected QGIS version: master
Redmine category:qgis_server
Assignee: Marco Hugentobler

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Hi,
I'm testing the qgis-server from trunk version.

I see that the legend graphics return from a GetLegendGraphics request if truncate if there the scale parameter.

some samples:

thsi is is with scale parameter:
http://www502.regione.toscana.it/geoscopio_qg/cgi-bin/qgis_mapserv?map=continuum_geologico_rt.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=frane&style=default&legend_options=fontName:Verdana;fontSize:10&scale=7927.372584308516

And this is the same without the scale parameter.
http://www502.regione.toscana.it/geoscopio_qg/cgi-bin/qgis_mapserv?map=continuum_geologico_rt.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=frane&style=default&legend_options=fontName:Verdana;fontSize:10&scale=7927.372584308516

Regards,

Andrea.

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• depositisuperficiali.zip (aperi2007 -)

[qgib]

Author Name: aperi2007 - (aperi2007 -)

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oops, the second was always with scale parameter.
this is really without scale parameter:

www502.regione.toscana.it/geoscopio_qg/cgi-bin/qgis_mapserv?map=continuum_geologico_rt.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=frane&style=default&legend_options=fontName:Verdana;fontSize:10

[qgib]

Author Name: Giovanni Manghi (@gioman)

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why blocker? it used to work in previous qgis releases?

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• category_id was configured as QGIS Server
• version was changed from 2.2.0 to master

[qgib]

Author Name: Marco Hugentobler (@mhugent)

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• assigned_to_id was configured as Marco Hugentobler

[qgib]

Author Name: aperi2007 - (aperi2007 -)

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I confirm it was also on QGIS 2.2 ,
but now is more badly.

Infact This is a sample from qgis-server 2.2:

QGIS 2.2 With scale parameter:
http://www502.regione.toscana.it/wmsraster2/qgis/wms?map=/maps/zz_contgeo.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=franacart&style=default&legend_options=fontName:Verdana;fontSize:10&scale=7927.372584308516

QGIS 2.2 without the scale parameter:
http://www502.regione.toscana.it/wmsraster2/qgis/wms?map=/maps/zz_contgeo.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=franacart&style=default&legend_options=fontName:Verdana;fontSize:10

As yiu can see it break on the last domain.
So the user can effectlively see something , and all doamins are more or less visible.

INSTEAD
in qgis 2.4 this is the situation:

QGIS 2.4 with scale parameter:
http://www502.regione.toscana.it/geoscopio_qg/cgi-bin/qgis_mapserv?map=continuum_geologico_rt.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=frane&style=default&legend_options=fontName:Verdana;fontSize:10&scale=7927.372584308516

QGIS 2.4 without the scale parameter:
http://www502.regione.toscana.it/geoscopio_qg/cgi-bin/qgis_mapserv?map=continuum_geologico_rt.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=frane&style=default&legend_options=fontName:Verdana;fontSize:10

As you can see on QGIS 2.4 it lost fully two domains and a third is half.

So the QGIS 2.4 situation is worst than QGIS 2.2.

guess the Legend readability is an important question for a GIS system.
And I guess this is a worst question.

Of course this is only my opinion.

But effectively this is not a blocking question because as a workaround,
I could add two fake domains to be the last two values and invisibles (all white) to enlarge the image and retrieve so the two lost.
:)

Regards,

Andrea.

[qgib]

Author Name: Marco Hugentobler (@mhugent)

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What is the style of the layer (rule based renderer?), could you attach a .qml file?

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• status_id was changed from Open to Feedback

[qgib]

Author Name: aperi2007 - (aperi2007 -)

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Is a categorized rendering.

The QML of that image is quite complex because has a dual level rendering for every domains and with a point pattern inside using SVGs.
and also a data-definition use for rotation of patterns and also an expression controlled color border.

I will try to test and reproduce the bug on a more simple qml.

[qgib]

Author Name: aperi2007 - (aperi2007 -)

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Hi.

I confirm the problem is also with more simple qml.

This as example:
With the scale parameter the last domains are lost.

http://www502.regione.toscana.it/geoscopio_qg/cgi-bin/qgis_mapserv?map=continuum_geologico_rt.qgs&SERVICE=WMS&request=GetLegendGraphic&version=1.1.1&format=image/png&sld_version=1.1.0&width=23&height=15&layer=depositisuperficiali&style=default&legend_options=fontName:Verdana;fontSize:10&scale=7927.372584308516

The qmls of this legend map is more simple than other and I can share the QML.
I attach it to this thread.

Regards,

Andrea.

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• 7418 was configured as depositisuperficiali.zip

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• depositisuperficiali.zip (aperi2007 -) - The QML with categorized rendering.

[qgib]

Author Name: Marco Hugentobler (@mhugent)

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Ok, I imported the qml to my simple test project (layer does not match, but it does not matter for LegendGraphic). Issuing the example request (only map and layer params replaced), I get the full legend with and without scale parameter.

I've committed a fix for a crash about an hour ago. Are you also working with that version (d8a0361) ? Though I cannot see how that fix would have any influence on the size of the generated image...

[qgib]

Author Name: aperi2007 - (aperi2007 -)

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ok,
Yes I confirm.
I have update the server to the last updates truk and the ussue is disappeared.

Thx Marco,

A.

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• resolution was changed from to fixed/implemented
• status_id was changed from Feedback to Closed