I have an application which has perform a HTTP request (which will handle some map transformations) before starting fetching WMS tiles from server.

Is there a way to pause TileWMS auto-refreshing after dragging the map?

Setting invisible or removing and adding the layer will work, but I don't want the layer to disappear while performing the HTTP request. I also tried setUrl('') but the layer will also disappear.

EDIT:
I also tried to read openlayers source code to define a property to be checked before performing the requests but I couldn't find in code where the requests are made.