er.ajax
Class AjaxProxy

java.lang.Object
  com.webobjects.appserver.WOElement
      com.webobjects.appserver.WOComponent
          er.ajax.AjaxComponent
              er.ajax.AjaxProxy

All Implemented Interfaces:

com.webobjects.appserver.WOActionResults, com.webobjects.foundation.NSKeyValueCoding, com.webobjects.foundation.NSKeyValueCoding.ErrorHandling, com.webobjects.foundation.NSKeyValueCodingAdditions, com.webobjects.foundation.NSValidation, IAjaxElement, java.io.Serializable, java.lang.Cloneable

public class AjaxProxy
extends AjaxComponent

Handles javascript-java communication (client-server) between the javascript world running in a web browser and the java world, running in a WebObject application. This remote-procedure-call communication is done using json protocol, as implemented by the JSON-RPC library.

This component generate javascript code that will initialize a variable that will be the starting point for rpc communication. The name of this variable is given in the name binding. There will be an object, server side that will be the proxy and will handle the request. You can define the proxy on the server side (it has to be a JSONRPCBridge). The proxy will be your window to the java world, from there you can access your java objects from the javascript side. The name for this java variable is proxyName. By default, it will configure the parent component as one java proxy object and name it wopage from the javascript side. A JSONRPCBridge object is created if not given as a binding. If the binding is there but the value is null, it will create the bridge then push it to the binding. That way, you can configure a single bridge for multiple proxy objects. It is of good practice to provide a value in a binding (at least a binding) so that the object is not created on every ajax request.

The proxy object will be the one visible for RPC from the javascript world. For example, the following binding:
PageProxy : AjaxProxy {
proxyName = "wopage";
name = "jsonrpc";
}
will be used as follow :

JavaScript (client)	Java (server)
// index of the selection on the client; var idx = 3; // fixed value for the demo // using rpc, ask our page to get the name for that client for that index. var nom = jsonrpc.wopage.clientNameAtIndex(idx);	// Java-WebObject side, we receive the index and simple return what they asked for, as for any java call. public String clientNameAtIndex(int i) { return "something!"+i; }

Remember that is no proxy object is given, it will use the parent component, which is the component in which this component is embeded.

Todo

• Complete the JSON-RPC integration to be able to leverage all possibilities of that library (foreign references, etc.).

Version:

$Revision $, $Date $
© 2005-2006 OS communications informatiques, inc. http://www.os.ca Tous droits réservés.

See Also:

Serialized Form

Author:

Jean-François Veillette

Bindings

proxy	Server side object (Java) that will be visible for rpc communication (Javascript). If no object is bound, the parent() object is assigned by default.
proxyName	Client side name (Javascript) used to identify the proxy (Java) from the bridge object.
name	Client side name (Javascript) of the bridge object.
JSONRPCBridge	Server side object (Java) used to handle the request. Of no value are bound, a new object is created for every ajax request. If a binding is there but null value, a new object will be created and pushed to the binding so that this new object can be shared for multiple proxy.

Nested Class Summary

Nested classes/interfaces inherited from class com.webobjects.appserver.WOComponent

com.webobjects.appserver.WOComponent._EventLoggingEnabler, com.webobjects.appserver.WOComponent.Event

Nested classes/interfaces inherited from interface com.webobjects.foundation.NSKeyValueCodingAdditions

com.webobjects.foundation.NSKeyValueCodingAdditions.DefaultImplementation, com.webobjects.foundation.NSKeyValueCodingAdditions.Utility

Nested classes/interfaces inherited from interface com.webobjects.foundation.NSKeyValueCoding

com.webobjects.foundation.NSKeyValueCoding._BooleanFieldBinding, com.webobjects.foundation.NSKeyValueCoding._BooleanMethodBinding, com.webobjects.foundation.NSKeyValueCoding._FieldBinding, com.webobjects.foundation.NSKeyValueCoding._ForwardingBinding, com.webobjects.foundation.NSKeyValueCoding._KeyBinding, com.webobjects.foundation.NSKeyValueCoding._KeyBindingCreation, com.webobjects.foundation.NSKeyValueCoding._MethodBinding, com.webobjects.foundation.NSKeyValueCoding._NumberFieldBinding, com.webobjects.foundation.NSKeyValueCoding._NumberMethodBinding, com.webobjects.foundation.NSKeyValueCoding._ReflectionKeyBindingCreation, com.webobjects.foundation.NSKeyValueCoding.ErrorHandling, com.webobjects.foundation.NSKeyValueCoding.Null, com.webobjects.foundation.NSKeyValueCoding.UnknownKeyException, com.webobjects.foundation.NSKeyValueCoding.ValueAccessor

Nested classes/interfaces inherited from interface com.webobjects.foundation.NSValidation

com.webobjects.foundation.NSValidation._MethodBinding, com.webobjects.foundation.NSValidation._ValidationBinding, com.webobjects.foundation.NSValidation.DefaultImplementation, com.webobjects.foundation.NSValidation.Utility, com.webobjects.foundation.NSValidation.ValidationException

Field Summary

Fields inherited from class com.webobjects.appserver.WOComponent

_Extension, _IsEventLoggingEnabled, _keyAssociations

Fields inherited from interface com.webobjects.foundation.NSKeyValueCoding.ErrorHandling

_CLASS

Fields inherited from interface com.webobjects.foundation.NSKeyValueCodingAdditions

_CLASS, _KeyPathSeparatorChar, KeyPathSeparator

Fields inherited from interface com.webobjects.foundation.NSKeyValueCoding

NullValue

Fields inherited from interface com.webobjects.foundation.NSValidation

_CLASS

Constructor Summary

AjaxProxy(com.webobjects.appserver.WOContext context)

Method Summary

protected void	addRequiredWebResources(com.webobjects.appserver.WOResponse res) Adds the jsonrpc.js script to the head in the response if not already present and also adds a javascript proxy for the supplied bridge under the name "JSONRPC_".
com.webobjects.appserver.WOActionResults	handleRequest(com.webobjects.appserver.WORequest request, com.webobjects.appserver.WOContext context) Ask the an JSONRPCBridge object to handle the json request.
boolean	isStateless() Overridden because the component is stateless
boolean	synchronizesVariablesWithBindings() Overridden because the component does not synch with the bindings.

Methods inherited from class er.ajax.AjaxComponent

_containerID, addScriptResourceInHead, addScriptResourceInHead, addStylesheetResourceInHead, addStylesheetResourceInHead, appendTagAttributeToResponse, appendToResponse, booleanValueForBinding, invokeAction, safeElementID, shouldHandleRequest, valueForBinding, valueForBinding, valueForBinding

Methods inherited from class com.webobjects.appserver.WOComponent

_associationWithName, _awakeInContext, _childTemplate, _componentDefinition, _componentUnroll, _isPage, _setContext, _setIsPage, _setParent, _setSubcomponent, _sleepInContext, _subcomponentForElementWithID, _templateNameForClass, _unroll, application, awake, baseURL, bindingKeys, canAccessFieldsDirectly, canGetValueForBinding, canSetValueForBinding, clone, context, debugString, descriptionForResponse, ensureAwakeInContext, frameworkName, generateResponse, handleQueryWithUnboundKey, handleTakeValueForUnboundKey, hasBinding, hasSession, isCachingEnabled, isEventLoggingEnabled, logString, name, pageWithName, parent, path, pathURL, performParentAction, pullValuesFromParent, pushValuesToParent, reset, session, set_componentUnroll, set_unroll, setCachingEnabled, setValueForBinding, sleep, takeValueForKey, takeValueForKeyPath, takeValuesFromRequest, template, templateWithHTMLString, templateWithName, toString, unableToSetNullForKey, validateTakeValueForKeyPath, validateValueForKey, validationFailedWithException, valueForBinding, valueForKey, valueForKeyPath

Methods inherited from class java.lang.Object

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

Constructor Detail

AjaxProxy

public AjaxProxy(com.webobjects.appserver.WOContext context)

Method Detail

isStateless

public boolean isStateless()

Overridden because the component is stateless

Overrides:

isStateless in class com.webobjects.appserver.WOComponent

synchronizesVariablesWithBindings

public boolean synchronizesVariablesWithBindings()

Overridden because the component does not synch with the bindings.

Overrides:

synchronizesVariablesWithBindings in class com.webobjects.appserver.WOComponent

addRequiredWebResources

protected void addRequiredWebResources(com.webobjects.appserver.WOResponse res)

Adds the jsonrpc.js script to the head in the response if not already present and also adds a javascript proxy for the supplied bridge under the name "JSONRPC_".

Specified by:

addRequiredWebResources in class AjaxComponent

Parameters:

res -

handleRequest

public com.webobjects.appserver.WOActionResults handleRequest(com.webobjects.appserver.WORequest request,
                                                              com.webobjects.appserver.WOContext context)

Ask the an JSONRPCBridge object to handle the json request.

Specified by:

handleRequest in interface IAjaxElement

Specified by:

handleRequest in class AjaxComponent