Why client.dart in route use gotopath rather than handle? - dart

Question

I asked to fix an issue in software which use dart to develop a chrome application. currently, the chrome application doesn't run in my mac osx and I get the following exception:
Uncaught Unhandled exception:
Class '_InternalLinkedHashMap' has no instance method 'pushState'.
NoSuchMethodError: method not found: 'pushState'
Receiver: _LinkedHashMap len:0
Arguments: [null, "", "/index.html#events"]
#0 Object._noSuchMethod (dart:core-patch/object_patch.dart:42)
#1 Object.noSuchMethod (dart:core-patch/object_patch.dart:45)
#2 Router._go (package:route/client.dart:153:22)
#3 Router.gotoPath (package:route/client.dart:139:7)
#4 Router.listen.<anonymous closure> (package:route/client.dart:111:13)
#5 wrap_event_listener.<anonymous closure>.<anonymous closure> (dart:html:1189)VM81:1 (anonymous function)
After I backtrace the issue, I found that listen() function instead of calling handle calls gotoPath(string,string). Can someone explain me that. this cause
[https://github.com/justinfagnani/route/blob/master/lib/client.dart][1]
void gotoPath(String path, String title) {
_logger.finest('gotoPath $path');
var url = _getUrl(path);
if (url != null) {
_go(path, title);
// If useFragment, onHashChange will call handle for us.
if (!_listen || !useFragment) {
_handlers[url](path);
}
}
}
void handle(String path) {
_logger.finest('handle $path');
var url = _getUrl(path);
if (url != null) {
// always give handlers a non-fragment path
var fixedPath = url.reverse(url.parse(path));
_handlers[url](fixedPath);
} else {
_logger.info("Unhandled path: $path");
}
}
this calls from here:
Note that other methods if/else call handle and only the !ignoreclick is call gotopath
void listen({bool ignoreClick: false}) {
_logger.finest('listen ignoreClick=$ignoreClick useFragment=$useFragment');
if (_listen) {
throw new StateError('listen should be called once.');
}
_listen = true;
if (useFragment) {
window.onHashChange.listen((_) {
var path = '${window.location.pathname}${window.location.hash}';
_logger.finest('onHashChange handle($path)');
return handle(path);
});
handle('${window.location.pathname}${window.location.hash}');
} else {
window.onPopState.listen((_) {
var path = '${window.location.pathname}${window.location.hash}';
_logger.finest('onPopState handle($path)');
handle(path);
});
}
if (!ignoreClick) {
window.onClick.listen((e) {
if (e.target is AnchorElement) {
AnchorElement anchor = e.target;
if (anchor.host == window.location.host) {
var fragment = (anchor.hash == '') ? '' : '${anchor.hash}';
gotoPath("${anchor.pathname}$fragment", anchor.title);
e.preventDefault();
}
}
});
}
}