/**
* Finds a UI ancestor of this connector. <code>null</code> is returned if no UI ancestor is found
* (typically because the connector is not attached to a proper hierarchy).
*
* @return the UI ancestor of this connector, or <code>null</code> if none is found.
*/
@Override
public UI getUI() {
ClientConnector connector = this;
while (connector != null) {
if (connector instanceof UI) {
return (UI) connector;
}
connector = connector.getParent();
}
return null;
}
/**
* Method for finding the error handler for the given connector. Uses connector hierarchy to find
* a connector with an error handler. Falls back to the VaadinSession error handler if no
* connector has specified an error handler.
*
* <p>Returns a {@link DefaultErrorHandler} if no error handler was found
*
* @param connector The target connector
* @return An ErrorHandler for the connector
*/
public static ErrorHandler findErrorHandler(ClientConnector connector) {
if (connector != null) {
ErrorHandler errorHandler = connector.getErrorHandler();
if (errorHandler != null) {
return errorHandler;
}
ClientConnector parent = connector.getParent();
if (parent != null) {
return findErrorHandler(parent);
}
/*
* Reached UI and found no error handler. Try session which
* typically has one.
*/
UI ui = connector.getUI();
if (ui != null) {
errorHandler = findErrorHandler(ui.getSession());
if (errorHandler != null) {
return errorHandler;
}
}
}
/*
* No connector known or the connector is not attached to a session. Try
* the current session
*/
if (VaadinSession.getCurrent() != null) {
ErrorHandler errorHandler = VaadinSession.getCurrent().getErrorHandler();
if (errorHandler != null) {
return errorHandler;
}
}
/*
* We should never really get here as at least the session should have
* an error handler. If for some reason it does not we use the default
* error handler.
*/
return new DefaultErrorHandler();
}
