org.rhq.scripting.javascript.engine
Class JSAdapter

java.lang.Object
  org.rhq.scripting.javascript.engine.JSAdapter

All Implemented Interfaces:

org.mozilla.javascript.Callable, org.mozilla.javascript.Function, org.mozilla.javascript.Scriptable

public final class JSAdapter
extends Object
implements org.mozilla.javascript.Scriptable, org.mozilla.javascript.Function

JSAdapter is java.lang.reflect.Proxy equivalent for JavaScript. JSAdapter calls specially named JavaScript methods on an adaptee object when property access is attempted on it. Example: var y = { __get__ : function (name) { ... } __has__ : function (name) { ... } __put__ : function (name, value) {...} __delete__ : function (name) { ... } __getIds__ : function () { ... } }; var x = new JSAdapter(y); x.i; // calls y.__get__ i in x; // calls y.__has__ x.p = 10; // calls y.__put__ delete x.p; // calls y.__delete__ for (i in x) { print(i); } // calls y.__getIds__ If a special JavaScript method is not found in the adaptee, then JSAdapter forwards the property access to the adaptee itself. JavaScript caller of adapter object is isolated from the fact that the property access/mutation/deletion are really calls to JavaScript methods on adaptee. Use cases include 'smart' properties, property access tracing/debugging, encaptulation with easy client access - in short JavaScript becomes more "Self" like. Note that Rhino already supports special properties like __proto__ (to set, get prototype), __parent__ (to set, get parent scope). We follow the same double underscore nameing convention here. Similarly the name JSAdapter is derived from JavaAdapter -- which is a facility to extend, implement Java classes/interfaces by JavaScript.

Since:

1.6

Version:

1.0

Author:

A. Sundararajan

Field Summary

Fields inherited from interface org.mozilla.javascript.Scriptable

NOT_FOUND

Method Summary

Object	call(org.mozilla.javascript.Context cx, org.mozilla.javascript.Scriptable scope, org.mozilla.javascript.Scriptable thisObj, Object[] args)
org.mozilla.javascript.Scriptable	construct(org.mozilla.javascript.Context cx, org.mozilla.javascript.Scriptable scope, Object[] args)
void	delete(int index)
void	delete(String name)
Object	get(int index, org.mozilla.javascript.Scriptable start)
Object	get(String name, org.mozilla.javascript.Scriptable start)
org.mozilla.javascript.Scriptable	getAdaptee()
String	getClassName()
Object	getDefaultValue(Class hint)
Object[]	getIds()
org.mozilla.javascript.Scriptable	getParentScope()
org.mozilla.javascript.Scriptable	getPrototype()
boolean	has(int index, org.mozilla.javascript.Scriptable start)
boolean	has(String name, org.mozilla.javascript.Scriptable start)
boolean	hasInstance(org.mozilla.javascript.Scriptable scriptable)
static void	init(org.mozilla.javascript.Context cx, org.mozilla.javascript.Scriptable scope, boolean sealed)
void	put(int index, org.mozilla.javascript.Scriptable start, Object value)
void	put(String name, org.mozilla.javascript.Scriptable start, Object value)
void	setAdaptee(org.mozilla.javascript.Scriptable adaptee)
void	setParentScope(org.mozilla.javascript.Scriptable parent)
void	setPrototype(org.mozilla.javascript.Scriptable prototype)

Methods inherited from class java.lang.Object

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

Method Detail

init

public static void init(org.mozilla.javascript.Context cx,
                        org.mozilla.javascript.Scriptable scope,
                        boolean sealed)
                 throws org.mozilla.javascript.RhinoException

Throws:

org.mozilla.javascript.RhinoException

getClassName

public String getClassName()

Specified by:

getClassName in interface org.mozilla.javascript.Scriptable

get

public Object get(String name,
                  org.mozilla.javascript.Scriptable start)

Specified by:

get in interface org.mozilla.javascript.Scriptable

get

public Object get(int index,
                  org.mozilla.javascript.Scriptable start)

Specified by:

get in interface org.mozilla.javascript.Scriptable

has

public boolean has(String name,
                   org.mozilla.javascript.Scriptable start)

Specified by:

has in interface org.mozilla.javascript.Scriptable

has

public boolean has(int index,
                   org.mozilla.javascript.Scriptable start)

Specified by:

has in interface org.mozilla.javascript.Scriptable

put

public void put(String name,
                org.mozilla.javascript.Scriptable start,
                Object value)

Specified by:

put in interface org.mozilla.javascript.Scriptable

put

public void put(int index,
                org.mozilla.javascript.Scriptable start,
                Object value)

Specified by:

put in interface org.mozilla.javascript.Scriptable

delete

public void delete(String name)

Specified by:

delete in interface org.mozilla.javascript.Scriptable

delete

public void delete(int index)

Specified by:

delete in interface org.mozilla.javascript.Scriptable

getPrototype

public org.mozilla.javascript.Scriptable getPrototype()

Specified by:

getPrototype in interface org.mozilla.javascript.Scriptable

setPrototype

public void setPrototype(org.mozilla.javascript.Scriptable prototype)

Specified by:

setPrototype in interface org.mozilla.javascript.Scriptable

getParentScope

public org.mozilla.javascript.Scriptable getParentScope()

Specified by:

getParentScope in interface org.mozilla.javascript.Scriptable

setParentScope

public void setParentScope(org.mozilla.javascript.Scriptable parent)

Specified by:

setParentScope in interface org.mozilla.javascript.Scriptable

getIds

public Object[] getIds()

Specified by:

getIds in interface org.mozilla.javascript.Scriptable

hasInstance

public boolean hasInstance(org.mozilla.javascript.Scriptable scriptable)

Specified by:

hasInstance in interface org.mozilla.javascript.Scriptable

getDefaultValue

public Object getDefaultValue(Class hint)

Specified by:

getDefaultValue in interface org.mozilla.javascript.Scriptable

call

public Object call(org.mozilla.javascript.Context cx,
                   org.mozilla.javascript.Scriptable scope,
                   org.mozilla.javascript.Scriptable thisObj,
                   Object[] args)
            throws org.mozilla.javascript.RhinoException

Specified by:

call in interface org.mozilla.javascript.Callable

Specified by:

call in interface org.mozilla.javascript.Function

Throws:

org.mozilla.javascript.RhinoException

construct

public org.mozilla.javascript.Scriptable construct(org.mozilla.javascript.Context cx,
                                                   org.mozilla.javascript.Scriptable scope,
                                                   Object[] args)
                                            throws org.mozilla.javascript.RhinoException

Specified by:

construct in interface org.mozilla.javascript.Function

Throws:

org.mozilla.javascript.RhinoException

getAdaptee

public org.mozilla.javascript.Scriptable getAdaptee()

setAdaptee

public void setAdaptee(org.mozilla.javascript.Scriptable adaptee)