[QGIS-Developer] QGIS Server request extra parameters as variables for expressions

[Richard Duivenvoorde]

On 23-11-17 16:46, Arnaud Morvan wrote:

> @Mathias :
> 
> Yes after taking a look, WMS dimensions is exactly the idea I have in mind.

Mmm,

I think Dimensions is a different case, as Dimensions are tied to WMS-T
[0] and the query parameter is defined as
&TIME=...,...
&TIME=...
etc
OR elevation:
&ELEVATION=

GeoServer has (besides dimensions) even some more use of 'variables'
which you can use in different places:

- possible variable substitutions in sld's [1]
&&env=name1:value1;name2=value2&...

- sql view parameters [2]
&viewparams=p1:v1;p2:v2;...

- format options in CQL queries [3]
&format_options=param1:value1;param2:value2;...

I think the 'expressions'-variables you are talking about are most close
to the viewparams (though if it only filters the styling itis a sld one...).

My point: let's define a 'common' param, shared between different FOSS
wms's instead of coming up with our own wheel :-)

Regards,

Richard Duivenvoorde

[0]
https://anitagraser.com/2011/06/10/wms-t-support-in-geoserver-and-mapserver/
[1]
http://docs.geoserver.org/stable/en/user/styling/sld/extensions/substitution.html
[2] http://docs.geoserver.org/latest/en/user/data/database/sqlview.html
[3] http://docs.geoserver.org/latest/en/user/services/wfs/vendor.html