Honour queryable field in layer info when bulding WMS getFeatureInfo request

[manisandro]

In QWC2, the entire project is published as one WMS with individual layers in
the QGIS project handled as sublayers of this WMS layer. We keep track of the
individual sublayers by extending the WMS layer params object with the fields:

sublayers: Array
opacities: Array
queryable: Array

This commit makes MapInfoUtils::buildIdentifyWMSRequest honour the queryable
array to exclude sublayers from the query which are flagged as non-identifyable.

[coveralls]

Coverage decreased (-0.02%) to 80.55% when pulling 476dbfe on sourcepole:wms_info_queryable into ffbaac9 on geosolutions-it:master.

[mbarto]

Is the queryable attribute of layers something custom to your application? I get it's an array of layers to be queried instead of the original layer. I think queryable is a misleading name. Usually queryable is a flag to distinguish layers that can be queries.

[manisandro]

It is custom in the sense that the upstream there is not support for WMS sublayer handling AFAICS. Say you have a WMS layer published as

somelayer
   |--> sublayer1
   |--> sublayer2
   etc

If you pass somelayer as layer parameter in the WMS request, it means the main layer including all possible sublayers. You can however select only certain sublayers by passing instead a comma-separated list of sublayer names, i.e. sublayer1,sublayer2. QGIS server (and possibly other WMS servers) can publish in the capabilities whether individual sublayers are "queryable" aka identifyable.

As for the name "queryable", I have no problems renaming it to "identifyable" or something else.

[mbarto]

Yes, please rename to something like queryLayers and I think it's good. If it's not too complex, please also add a unit test

[manisandro]

Actually I just noticed when grepping for queryable: there already are traces of a queryable field in the layer object [1], but I don't see other traces of it. Should I rename it also?

[1] https://github.com/geosolutions-it/MapStore2/blob/master/web/client/utils/MapInfoUtils.js#L223

[mbarto]

That's the flag I was referring too. It's coming from WMS capabilities to tell you if a layer is queryable or not.

[manisandro]

Ahh ok.

[coveralls]

Coverage decreased (-0.01%) to 80.572% when pulling 9297c8d on sourcepole:wms_info_queryable into 3fad9fd on geosolutions-it:master.

[mbarto]

Could you add a unit test also for this one?

[coveralls]

Coverage increased (+0.1%) to 80.706% when pulling 00f9317 on sourcepole:wms_info_queryable into 3fad9fd on geosolutions-it:master.