addPersistentStyleCustomLayer

Adds a new style custom layer.

Whenever a new style is being parsed and currently used style has persistent layers, an engine will try to do following:

  • keep the persistent layer at its relative position

  • keep the source used by a persistent layer

  • keep images added through addStyleImage method

In cases when a new style has the same layer, source or image resource, style's resources would be used instead and MapLoadingError event will be emitted.

Return

A string describing an error if the operation was not successful, or empty otherwise.

Parameters

layerId

A style layer identifier.

layerHost
layerPosition

If not empty, the new layer will be positioned according to LayerPosition parameters.