[QGIS-Developer] Missing custom rendering properties in QGIS3 Server

[Sören Gebbert]

Dear Nyall,
what would be an officially supported and stable implementation?

Are there any plans to implement this functionality in a better way so
it will work in desktop and server?

Can i help to implement this kind of functionality?

Best regards
Sören

2018-05-23 12:33 GMT+02:00 Nyall Dawson <nyall.dawson at gmail.com>:
> On 23 May 2018 at 18:56, Sören Gebbert <soerengebbert at googlemail.com> wrote:
>> Dear developers,
>> i am trying to use the undocumented custom vector layer property
>> "rendering/renderAboveLabels" in QGIS3 server with no success.
>>
>> Storing this property in a QGIS project file enables the rendering of
>> vector layers after the labeling is done. This works fine on QGIS3
>> desktop, but not on QGIS3 server. I looked into the server code and
>> realized that the QGS WMS server uses two renderers
>> (QgsMapRendererParallelJob, QgsMapRendererCustomPainterJob) of which
>> one (QgsMapRendererParallelJob) should support the custom property.
>> However, i can not convince the server to apply the custom property
>> when parallel rendering is enabled.
>>
>> What am i doing wrong? Are there differences between GQIS3 desktop and
>> server in handling project files and layer properties?
>>
>> Why does QgsMapRendererCustomPainterJob not support the custom
>> property  "rendering/renderAboveLabels"?
>
> It's undocumented for a reason - it was added as a quick hack to
> support this function in very limited circumstances, but isn't part of
> the stable or public API as it's not officially supported.
>
> In the long term we need a proper, officially supported and stable way
> to handle this use case.
>
> Nyall