Convenience method for importing an HTML document imperatively.
This method creates a new <link rel="import"> element with the provided URL and appends it to the document to start loading. In the onload callback, the import property of the link element will contain the imported document contents.
Dart note: These imports cannot contain dart script tags.
Source
LinkElement importHref(String href, {void onLoad(e), void onError(e)}) {
onLoad = Zone.current.bindUnaryCallback(onLoad);
onError = Zone.current.bindUnaryCallback(onError);
return jsElement.callMethod('importHref', [href, onLoad, onError]);
}