openlayers 4: force refresh tiles in ol.source.VectorTile on interval

Question

I'm using openlayers 4, and have a ol.source.VectorTile which uses MVT tiles. I want to refresh the tiles every 5 seconds without refreshing the browser. I've used source.changed(), source.refresh(), layer.changed() and map.renderSync()

But none of them not working for me, I mean tiles not refreshed after calling any of them.

Can anyone help me please.

Answer 1

I finally found a solution to force ol.source.VectorTile layer to refresh tiles. This is the first step to create my vector tile layer:

var layer = ol.layer.VectorTile({
    preload: 0,
    source: new ol.source.VectorTile({
        cacheSize: 1,
        format: new ol.format.MVT({
            featureClass: ol.Feature
        }),
    })
});

And layer in my refresh function do this:

function refresh() {
    var source = layer.getSource();
    source.tileCache.expireCache({});
    source.tileCache.clear();
    source.refresh();
}

Answer 2

I am setting myself a little helper function to reload a layer.

Expiring and clearing the tile cache does not seem to have any effect on the procedure. I do however need to redraw the layer. Just updating the source will not automatically trigger a layer redraw.

  layer.reload = () => {

    //source.tileCache.expireCache();
    //source.tileCache.clear();

    source.clear();
    source.refresh({force: true});

    layer.redraw();

  };