com.vaadin.terminal
Class AbstractJavaScriptExtension

java.lang.Object
  com.vaadin.terminal.AbstractClientConnector
      com.vaadin.terminal.AbstractExtension
          com.vaadin.terminal.AbstractJavaScriptExtension

All Implemented Interfaces:

Extension, Connector, ClientConnector, RpcTarget, Serializable

public abstract class AbstractJavaScriptExtension
extends AbstractExtension

Base class for Extensions with all client-side logic implemented using JavaScript.

When a new JavaScript extension is initialized in the browser, the framework will look for a globally defined JavaScript function that will initialize the extension. The name of the initialization function is formed by replacing . with _ in the name of the server-side class. If no such function is defined, each super class is used in turn until a match is found. The framework will thus first attempt with com_example_MyExtension for the server-side com.example.MyExtension extends AbstractJavaScriptExtension class. If MyExtension instead extends com.example.SuperExtension , then com_example_SuperExtension will also be attempted if com_example_MyExtension has not been defined.

The initialization function will be called with this pointing to a connector wrapper object providing integration to Vaadin with the following functions:

• getConnectorId() - returns a string with the id of the connector.
• getParentId([connectorId]) - returns a string with the id of the connector's parent. If connectorId is provided, the id of the parent of the corresponding connector with the passed id is returned instead.
• getElement([connectorId]) - returns the DOM Element that is the root of a connector's widget. null is returned if the connector can not be found or if the connector doesn't have a widget. If connectorId is not provided, the connector id of the current connector will be used.
• getState() - returns an object corresponding to the shared state defined on the server. The scheme for conversion between Java and JavaScript types is described bellow.
• registerRpc([name, ] rpcObject) - registers the rpcObject as a RPC handler. rpcObject should be an object with field containing functions for all eligible RPC functions. If name is provided, the RPC handler will only used for RPC calls for the RPC interface with the same fully qualified Java name. If no name is provided, the RPC handler will be used for all incoming RPC invocations where the RPC method name is defined as a function field in the handler. The scheme for conversion between Java types in the RPC interface definition and the JavaScript values passed as arguments to the handler functions is described bellow.
• getRpcProxy([name]) - returns an RPC proxy object. If name is provided, the proxy object will contain functions for all methods in the RPC interface with the same fully qualified name, provided a RPC handler has been registered by the server-side code. If no name is provided, the returned RPC proxy object will contain functions for all methods in all RPC interfaces registered for the connector on the server. If the same method name is present in multiple registered RPC interfaces, the corresponding function in the RPC proxy object will throw an exception when called. The scheme for conversion between Java types in the RPC interface and the JavaScript values that should be passed to the functions is described bellow.

The connector wrapper also supports these special functions:

• onStateChange - If the JavaScript code assigns a function to the field, that function is called whenever the contents of the shared state is changed.
• Any field name corresponding to a call to registerCallback(String, JavaScriptCallback) on the server will automatically be present as a function that triggers the registered callback on the server.
• Any field name referred to using invokeCallback(String, Object...) on the server will be called if a function has been assigned to the field.

Values in the Shared State and in RPC calls are converted between Java and JavaScript using the following conventions:

• Primitive Java numbers (byte, char, int, long, float, double) and their boxed types (Byte, Character, Integer, Long, Float, Double) are represented by JavaScript numbers.
• The primitive Java boolean and the boxed Boolean are represented by JavaScript booleans.
• Java Strings are represented by JavaScript strings.
• List, Set and all arrays in Java are represented by JavaScript arrays.
• Map in Java is represented by JavaScript object with fields corresponding to the map keys.
• Any other Java Map is represented by a JavaScript array containing two arrays, the first contains the keys and the second contains the values in the same order.
• A Java Bean is represented by a JavaScript object with fields corresponding to the bean's properties.
• A Java Connector is represented by a JavaScript string containing the connector's id.
• A pluggable serialization mechanism is provided for types not described here. Please refer to the documentation for specific types for serialization information.

Since:

7.0.0

Version:

7.0.0.alpha3

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

AbstractJavaScriptExtension()

Method Summary

JavaScriptExtensionState	getState() Gets the current shared state of the connector.
protected void	invokeCallback(String name, Object... arguments) Invoke a named function that the connector JavaScript has added to the JavaScript connector wrapper object.
protected void	registerCallback(String functionName, JavaScriptCallback javaScriptCallback) Register a JavaScriptCallback that can be called from the JavaScript using the provided name.
protected <T> void	registerRpc(T implementation, Class<T> rpcInterfaceType) Registers an RPC interface implementation for this component.

Methods inherited from class com.vaadin.terminal.AbstractExtension

extend, getSupportedParentType, removeFromTarget, setParent

Methods inherited from class com.vaadin.terminal.AbstractClientConnector

addExtension, addMethodInvocationToQueue, attach, createState, detach, getAllChildrenIterable, getApplication, getConnectorId, getExtensions, getParent, getRoot, getRpcManager, getRpcProxy, getStateType, isConnectorEnabled, registerRpc, removeExtension, requestRepaint, requestRepaintAll, retrievePendingRpcCalls

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.vaadin.terminal.gwt.server.ClientConnector

attach, detach, getExtensions, getParent, getRoot, getStateType, isConnectorEnabled, removeExtension, requestRepaint, requestRepaintAll, retrievePendingRpcCalls

Methods inherited from interface com.vaadin.terminal.gwt.client.Connector

getConnectorId

Methods inherited from interface com.vaadin.terminal.gwt.server.RpcTarget

getRpcManager

Constructor Detail

AbstractJavaScriptExtension

public AbstractJavaScriptExtension()

Method Detail

registerRpc

protected <T> void registerRpc(T implementation,
                               Class<T> rpcInterfaceType)

Description copied from class: AbstractClientConnector

Registers an RPC interface implementation for this component. A component can listen to multiple RPC interfaces, and subclasses can register additional implementations.

Overrides:

registerRpc in class AbstractClientConnector

Parameters:

implementation - RPC interface implementation

rpcInterfaceType - RPC interface class for which the implementation should be registered

registerCallback

protected void registerCallback(String functionName,
                                JavaScriptCallback javaScriptCallback)

Register a JavaScriptCallback that can be called from the JavaScript using the provided name. A JavaScript function with the provided name will be added to the connector wrapper object (initially available as this). Calling that JavaScript function will cause the call method in the registered JavaScriptCallback to be invoked with the same arguments.

Parameters:

functionName - the name that should be used for client-side callback

javaScriptCallback - the callback object that will be invoked when the JavaScript function is called

invokeCallback

protected void invokeCallback(String name,
                              Object... arguments)

Invoke a named function that the connector JavaScript has added to the JavaScript connector wrapper object. The arguments should only contain data types that can be represented in JavaScript including primitives, their boxed types, arrays, String, List, Set, Map, Connector and JavaBeans.

Parameters:

name - the name of the function

arguments - function arguments

getState

public JavaScriptExtensionState getState()

Description copied from interface: Connector

Gets the current shared state of the connector.

Specified by:

getState in interface Connector

Overrides:

getState in class AbstractClientConnector

Returns:

state The shared state object. Can be any sub type of SharedState. Never null.