Refresh MapLibre layer' source when the tiles are older than a given TTL

tiles_refresh.js

window.__refresh__ = false; // global flag to check whether to refresh or not
const ttl = 1000 * 60 * 60; // tile time to live, ms

const map = new maplibregl.Map(
    {
        ...,
        transformRequest: (url, resourceType) => {
            if (resourceType === 'Source' && url.indexOf('http://myHost') > -1) {
                if(window.__refresh__){
                    return {'url':`${url}${(url.indexOf('?') > -1) ? '&' : '?'}tick=${Date.now()}`}
                }else{
                    return {'url':url}
                }
            }
        }
    }
);

map.on('idle', inputlayer, e => {
    const
        source = e.sourceId,
        sourceCache = this.style.sourceCaches[source],
        sampleTileZXY = sourceCache.getRenderableIds().map((id) => sourceCache.getTileByID(id).tileID.canonical)[0],
        http = new XMLHttpRequest(),
        datelimit = new Date(Date.now() - ttl).toGMTString(),
        sourceURL = this.getSource('source').url || this.getSource('source').tiles[0],
        tileURL = sourceURL.replace('{z}', sampleTileZXY.z).replace('{x}', sampleTileZXY.x).replace('{y}', sampleTileZXY.y);

    http.open('HEAD', url, false);
    http.setRequestHeader('If-Modified-Since', datelimit);
    http.send();

    window.__refresh__ = http.status !== 304;

});