getFeatureInfo returning null from Azure maps WMS service

Question

Hello,

I'm trying to load the following WMS service: https://gin.gw-info.net/service/gin/wms/mediator/gin_en?request=GetCapabilities&version=1.1.0&service=WMS

I would like to display the underlying features of this WMS service via popup upon mapclick. For this, I use the azure maps getFeatureInfo function. Unfortunately, I don't seem to be getting any features returned and printing out the result shows that this function call returns null. Below is my code using this service:

let options = { 								
url: '
bringIntoView: true,
debug: true,
opacity: 0.60
}
options.activeLayers = ['WaterWells']
let layer = new atlas.layer.OgcMapLayer(options);
map.layers.add(layer, 'transit');

function mapClick(e) { 								
	layer.getFeatureInfo(e.position).then(result => {
		if (result && result.features && result.features.length > 0) {
			popup.setOptions({
				content: atlas.PopupTemplate.applyTemplate(result.features[0].properties),
				position: e.position
			});
			
			popup.open(map);
		}
	})
}

I tried loading the same WMS service on QGIS software and there seems to be features available in this WMS service. I've attached a screenshot of the features loaded for WaterWells sublayer from the url.

I tried by changing the service version from 1.1.0 to 1.3.0 but the same issue persists.

I would really appreciate some help on this!

Best Regards,

Aakash

Answer 1

Looking into this service it can only return feature information as HTML, not as a raw WFS response. If you look at the GetCapabilities XML for the WMS service you linked to, you will see under GetFeatureInfo section that it only supports HTML formats. So, instead of using getFeatureInfo you should use the getFeatureInfoHtml function https://learn.microsoft.com/en-us/javascript/api/azure-maps-spatial-io/atlas.layer.ogcmaplayer?view=azure-maps-typescript-latest#azure-maps-spatial-io-atlas-layer-ogcmaplayer-getfeatureinfohtml

Here is an example of how to modify your mapClick function:

function mapClick(e) { 								
	layer.getFeatureInfoHtml(e.position).then(result => {
		if (result) {
			popup.setOptions({
				content: result,
				position: e.position
			});
			
			popup.open(map);
		}
	})
}

Unfortunately, while looking into this I found that there is a bug with the getFeatureInfoHtml function. I found the following workaround for this bug:

layer.getCapabilities().then(cap => {
	if (cap && !cap._canGetFeatureInfo && cap._canGetHtmlFeatureInfo){
		cap._canGetFeatureInfo = true;
	}
});

That said, I found that this service more often than not returned an empty HTML page.

Answer 2

Thank you for bringing this to our attention. I have notified our SDK team, and they will address the issue in the upcoming release by implementing a fix.