topic Selecting a feature from FeatureCollectionLayer in Kotlin Maps SDK Questions

Selecting a feature from FeatureCollectionLayer

DavidCasillas — Mon, 24 Jul 2023 20:43:41 GMT

Hi,

I'm using a FeatureCollectionLayer to load custom geometry and attributes on my map. I have no problem displaying points on the map. But I do have an issue when selecting a feature.

Here is how I'm calling the tap method:

lifecycleScope.launch { mapView.onSingleTapConfirmed.collect { event -> selectFeature(event.screenCoordinate) } }

Here's the method to select feature:

private suspend fun selectFeature(coordinate: ScreenCoordinate) { val layer = featureCollectionLayer.layers.value[0] layer.clearSelection() val layerResult = mapView.identifyLayer(layer, coordinate, 25.0, false, -1) layerResult.apply { onSuccess { result -> val features = result.geoElements.filterIsInstance<Feature>() if (features.isEmpty()) { Log.d(localClassName, "No feature selected") return@onSuccess } val selectedFeature = features[0] layer.selectFeatures(features) Snackbar.make( mapView, "${selectedFeature.attributes["Name"]} selected", Snackbar.LENGTH_SHORT ).show() } onFailure { val errorMessage = "Select feature failed: " + it.message Log.e(localClassName, errorMessage) Snackbar.make(mapView, errorMessage, Snackbar.LENGTH_SHORT).show() } } }

Based on what I have logged ("No feature selected"), it seems there are no features, but the points do display. If anyone can see an issue, that would be greatly appreciated.

Thanks,

Dave

Re: Selecting a feature from FeatureCollectionLayer

PuneetPrakash — Tue, 25 Jul 2023 23:39:46 GMT

Maybe the points that are displaying are on a different FeatureLayer that you are performing the Identify operation on ?
You can try using identify layers function instead. This will perform identify operation on all layers in the view.

Re: Selecting a feature from FeatureCollectionLayer

DavidCasillas — Wed, 26 Jul 2023 00:21:33 GMT

Thank you for the response. I was able to identify the feature collection layers on my map with no issues. I'm still not getting anything when tapping on a feature.

Re: Selecting a feature from FeatureCollectionLayer

DavidCasillas — Wed, 26 Jul 2023 09:35:50 GMT

I was able to figure out how to select the features. Here's an updated code:

private suspend fun selectFeature(coordinate: ScreenCoordinate) { val layer = featureCollectionLayer.layers.value[0] layer.clearSelection() val layerResult = mapView.identifyLayer(featureCollectionLayer, coordinate, 25.0, false, -1) layerResult.apply { onSuccess { result -> val features = mutableListOf<Feature>() result.sublayerResults.forEach { subResults -> features.addAll(subResults.geoElements.filterIsInstance<Feature>()) } if (features.isEmpty()) { Log.d(localClassName, "No feature selected") return@onSuccess } val selectedFeature = features[0] layer.selectFeatures(features) Snackbar.make( mapView, "${selectedFeature.attributes["Name"]} selected", Snackbar.LENGTH_SHORT ).show() } onFailure { val errorMessage = "Select feature failed: " + it.message Log.e(localClassName, errorMessage) Snackbar.make(mapView, errorMessage, Snackbar.LENGTH_SHORT).show() } } }

I guess when selecting features from a FeatureCollectionLayer, you must identify those features from the sublayerResults.