com.vaadin.client.communication

Interface ConnectionStateHandler

All Known Implementing Classes:

DefaultConnectionStateHandler

public interface ConnectionStateHandler

Interface for handling problems and other events which occur during communication with the server. The handler is responsible for handling any problem in XHR, heartbeat and push connections in a way it sees fit. The default implementation is DefaultConnectionStateHandler.

Since:

1.0

Author:

Vaadin Ltd

Field Summary

Fields

Modifier and Type	Field and Description
static String	UIDL_REFRESH_TOKEN A string that, if found in a non-JSON response to a UIDL request, will cause the browser to refresh the page.

Method Summary

Modifier and Type	Method and Description
void	configurationUpdated() Called when some part of the reconnect dialog configuration has been changed.
void	heartbeatException(com.google.gwt.xhr.client.XMLHttpRequest request, Exception exception) Called when an exception occurs during a Heartbeat request.
void	heartbeatInvalidStatusCode(com.google.gwt.xhr.client.XMLHttpRequest xhr) Called when a heartbeat request returns a status code other than OK (200).
void	heartbeatOk() Called when a Heartbeat request succeeds.
void	pushClientTimeout(PushConnection pushConnection, com.google.gwt.core.client.JavaScriptObject response) Called when a client side timeout occurs before a push connection to the server completes.
void	pushClosed(PushConnection pushConnection, com.google.gwt.core.client.JavaScriptObject responseObject) Called when the push connection to the server is closed.
void	pushError(PushConnection pushConnection, com.google.gwt.core.client.JavaScriptObject response) Called when a fatal error fatal error occurs in the push connection.
void	pushInvalidContent(PushConnection pushConnection, String message) Called when invalid content (not JSON) was pushed from the server through the push connection.
void	pushNotConnected(elemental.json.JsonObject payload) Called when a message is to be sent to the server through the push channel but the push channel is not connected.
void	pushOk(PushConnection pushConnection) Called when the push connection to the server has been established.
void	pushReconnectPending(PushConnection pushConnection) Called when the push connection has lost the connection to the server and will proceed to try to re-establish the connection.
void	pushScriptLoadError(String resourceUrl) Called when the required push script could not be loaded.
void	xhrException(XhrConnectionError xhrConnectionError) Called when an exception occurs during an XmlHttpRequest request to the server.
void	xhrInvalidContent(XhrConnectionError xhrConnectionError) Called when invalid content (not JSON) was returned from the server as the result of an XmlHttpRequest request.
void	xhrInvalidStatusCode(XhrConnectionError xhrConnectionError) Called when invalid status code (not 200) was returned by the server as the result of an XmlHttpRequest.
void	xhrOk() Called whenever a XmlHttpRequest to the server completes successfully.

Field Detail

UIDL_REFRESH_TOKEN

static final String UIDL_REFRESH_TOKEN

A string that, if found in a non-JSON response to a UIDL request, will cause the browser to refresh the page. If followed by a colon, optional whitespace, and a URI, causes the browser to synchronously load the URI.

This allows, for instance, a servlet filter to redirect the application to a custom login page when the session expires. For example:

 if (sessionExpired) {
     response.setHeader("Content-Type", "text/html");
     response.getWriter().write(myLoginPageHtml + "<!-- Vaadin-Refresh: "
             + request.getContextPath() + " -->");
 }
 

See Also:

Constant Field Values

Method Detail

heartbeatException

void heartbeatException(com.google.gwt.xhr.client.XMLHttpRequest request,
                        Exception exception)

Called when an exception occurs during a Heartbeat request.

Parameters:

request - The heartbeat request

exception - The exception which occurred

heartbeatInvalidStatusCode

void heartbeatInvalidStatusCode(com.google.gwt.xhr.client.XMLHttpRequest xhr)

Called when a heartbeat request returns a status code other than OK (200).

Parameters:

xhr - the heartbeat request

heartbeatOk

void heartbeatOk()

Called when a Heartbeat request succeeds.

pushClosed

void pushClosed(PushConnection pushConnection,
                com.google.gwt.core.client.JavaScriptObject responseObject)

Called when the push connection to the server is closed. This might result in the push connection trying a fallback connection method, trying to reconnect to the server or might just be an indication that the connection was intentionally closed ("unsubscribe"),

Parameters:

pushConnection - The push connection which was closed

responseObject - An object containing response data

pushClientTimeout

void pushClientTimeout(PushConnection pushConnection,
                       com.google.gwt.core.client.JavaScriptObject response)

Called when a client side timeout occurs before a push connection to the server completes. The client side timeout causes a disconnection of the push connection and no reconnect will be attempted after this method is called,

Parameters:

pushConnection - The push connection which timed out

response - An object containing response data

pushError

void pushError(PushConnection pushConnection,
               com.google.gwt.core.client.JavaScriptObject response)

Called when a fatal error fatal error occurs in the push connection. The push connection will not try to recover from this situation itself and typically the problem handler should not try to do automatic recovery either. The cause can be e.g. maximum number of reconnection attempts have been reached, neither the selected transport nor the fallback transport can be used or similar.

Parameters:

pushConnection - The push connection where the error occurred

response - An object containing response data

pushReconnectPending

void pushReconnectPending(PushConnection pushConnection)

Called when the push connection has lost the connection to the server and will proceed to try to re-establish the connection.

Parameters:

pushConnection - The push connection which will be reconnected

pushOk

void pushOk(PushConnection pushConnection)

Called when the push connection to the server has been established.

Parameters:

pushConnection - The push connection which was established

pushScriptLoadError

void pushScriptLoadError(String resourceUrl)

Called when the required push script could not be loaded.

Parameters:

resourceUrl - The URL which was used for loading the script

xhrException

void xhrException(XhrConnectionError xhrConnectionError)

Called when an exception occurs during an XmlHttpRequest request to the server.

Parameters:

xhrConnectionError - An event containing what was being sent to the server and what exception occurred

xhrInvalidContent

void xhrInvalidContent(XhrConnectionError xhrConnectionError)

Called when invalid content (not JSON) was returned from the server as the result of an XmlHttpRequest request.

Parameters:

xhrConnectionError - An event containing what was being sent to the server and what was returned

xhrInvalidStatusCode

void xhrInvalidStatusCode(XhrConnectionError xhrConnectionError)

Called when invalid status code (not 200) was returned by the server as the result of an XmlHttpRequest.

Parameters:

xhrConnectionError - An event containing what was being sent to the server and what was returned

xhrOk

void xhrOk()

Called whenever a XmlHttpRequest to the server completes successfully.

pushNotConnected

void pushNotConnected(elemental.json.JsonObject payload)

Called when a message is to be sent to the server through the push channel but the push channel is not connected.

Parameters:

payload - The payload to send to the server

pushInvalidContent

void pushInvalidContent(PushConnection pushConnection,
                        String message)

Called when invalid content (not JSON) was pushed from the server through the push connection.

Parameters:

pushConnection - the push connection which was used

message - the received message

configurationUpdated

void configurationUpdated()

Called when some part of the reconnect dialog configuration has been changed.