saveUrlState method
Implementation
void saveUrlState(String varName, String value) {
final oldHash = window.location.hash;
if (oldHash.contains(urlStateDivider)) {
final split = oldHash.split(urlStateDivider);
final urlInfo = ViewUrlInfo.fromUrl(oldHash);
urlInfo.urlState[varName] = value;
window.history.replaceState(
{}, '', '${split.first}$urlStateDivider${urlInfo.urlStateString}');
} else {
final urlInfo = ViewUrlInfo();
urlInfo.urlState[varName] = value;
window.history.replaceState(
{}, '', '$oldHash$urlStateDivider${urlInfo.urlStateString}');
}
}