org.mozilla.javascript

Class FunctionObject

Implemented Interfaces:
Callable, ConstProperties, DebuggableObject, Function, IdFunctionCall, Scriptable, Serializable

public class FunctionObject
extends BaseFunction

Field Summary

static int
JAVA_BOOLEAN_TYPE
static int
JAVA_DOUBLE_TYPE
static int
JAVA_INT_TYPE
static int
JAVA_OBJECT_TYPE
static int
JAVA_SCRIPTABLE_TYPE
static int
JAVA_STRING_TYPE
static int
JAVA_UNSUPPORTED_TYPE

Fields inherited from class org.mozilla.javascript.ScriptableObject

CONST, DONTENUM, EMPTY, PERMANENT, READONLY, UNINITIALIZED_CONST

Fields inherited from interface org.mozilla.javascript.Scriptable

NOT_FOUND

Constructor Summary

FunctionObject(String name, Member methodOrConstructor, Scriptable scope)
Create a JavaScript function object from a Java method.

Method Summary

void
addAsConstructor(Scriptable scope, Scriptable prototype)
Define this function as a JavaScript constructor.
Object
call(Context cx, Scriptable scope, Scriptable thisObj, Object[] args)
Performs conversions on argument types if needed and invokes the underlying Java method or constructor.
static Object
convertArg(Context cx, Scriptable scope, Object arg, Class desired)
Deprecated. Use getTypeTag(Class) and convertArg(Context,Scriptable,Object,int) for type convertion.
static Object
convertArg(Context cx, Scriptable scope, Object arg, int typeTag)
Scriptable
createObject(Context cx, Scriptable scope)
Return new Scriptable instance using the default constructor for the class of the underlying Java method.
int
getArity()
Return the value defined by the method used to construct the object (number of parameters of the method, or 1 if the method is a "varargs" form).
String
getFunctionName()
int
getLength()
Return the same value as getArity().
Member
getMethodOrConstructor()
Get Java method or constructor this function represent.
static int
getTypeTag(Class type)

Methods inherited from class org.mozilla.javascript.BaseFunction

call, construct, createObject, execIdCall, fillConstructorProperties, findInstanceIdInfo, findPrototypeId, getArity, getClassName, getClassPrototype, getFunctionName, getInstanceIdName, getInstanceIdValue, getLength, getMaxInstanceId, hasInstance, initPrototypeId, setImmunePrototypeProperty, setInstanceIdValue

Methods inherited from class org.mozilla.javascript.IdScriptableObject

activatePrototypeMap, addIdFunctionProperty, defaultGet, defaultPut, delete, execIdCall, exportAsJSClass, fillConstructorProperties, findInstanceIdInfo, findPrototypeId, get, getAttributes, getInstanceIdName, getInstanceIdValue, getMaxInstanceId, has, hasPrototypeMap, incompatibleCallError, initPrototypeConstructor, initPrototypeId, initPrototypeMethod, initPrototypeValue, instanceIdInfo, put, setAttributes, setInstanceIdValue

Methods inherited from class org.mozilla.javascript.ScriptableObject

associateValue, callMethod, callMethod, defineClass, defineClass, defineClass, defineConst, defineConstProperty, defineFunctionProperties, defineProperty, defineProperty, defineProperty, defineProperty, delete, delete, deleteProperty, deleteProperty, equivalentValues, get, get, getAllIds, getAssociatedValue, getAttributes, getAttributes, getAttributes, getAttributes, getClassName, getClassPrototype, getDefaultValue, getDefaultValue, getFunctionPrototype, getGetterOrSetter, getIds, getObjectPrototype, getParentScope, getProperty, getProperty, getPropertyIds, getPrototype, getTopLevelScope, getTopScopeValue, has, has, hasInstance, hasProperty, hasProperty, isConst, isSealed, put, put, putConst, putConstProperty, putProperty, putProperty, redefineProperty, sealObject, setAttributes, setAttributes, setAttributes, setAttributes, setGetterOrSetter, setParentScope, setPrototype

Field Details

JAVA_BOOLEAN_TYPE

public static final int JAVA_BOOLEAN_TYPE
Field Value:
3

JAVA_DOUBLE_TYPE

public static final int JAVA_DOUBLE_TYPE
Field Value:
4

JAVA_INT_TYPE

public static final int JAVA_INT_TYPE
Field Value:
2

JAVA_OBJECT_TYPE

public static final int JAVA_OBJECT_TYPE
Field Value:
6

JAVA_SCRIPTABLE_TYPE

public static final int JAVA_SCRIPTABLE_TYPE
Field Value:
5

JAVA_STRING_TYPE

public static final int JAVA_STRING_TYPE
Field Value:
1

JAVA_UNSUPPORTED_TYPE

public static final int JAVA_UNSUPPORTED_TYPE
Field Value:
0

Constructor Details

FunctionObject

public FunctionObject(String name,
                      Member methodOrConstructor,
                      Scriptable scope)
Create a JavaScript function object from a Java method.

The member argument must be either a java.lang.reflect.Method or a java.lang.reflect.Constructor and must match one of two forms.

The first form is a member with zero or more parameters of the following types: Object, String, boolean, Scriptable, int, or double. The Long type is not supported because the double representation of a long (which is the EMCA-mandated storage type for Numbers) may lose precision. If the member is a Method, the return value must be void or one of the types allowed for parameters.

The runtime will perform appropriate conversions based upon the type of the parameter. A parameter type of Object specifies that no conversions are to be done. A parameter of type String will use Context.toString to convert arguments. Similarly, parameters of type double, boolean, and Scriptable will cause Context.toNumber, Context.toBoolean, and Context.toObject, respectively, to be called.

If the method is not static, the Java 'this' value will correspond to the JavaScript 'this' value. Any attempt to call the function with a 'this' value that is not of the right Java type will result in an error.

The second form is the variable arguments (or "varargs") form. If the FunctionObject will be used as a constructor, the member must have the following parameters

      (Context cx, Object[] args, Function ctorObj,
       boolean inNewExpr)
and if it is a Method, be static and return an Object result.

Otherwise, if the FunctionObject will not be used to define a constructor, the member must be a static Method with parameters (Context cx, Scriptable thisObj, Object[] args, Function funObj)

 and an Object result.

When the function varargs form is called as part of a function call, the args parameter contains the arguments, with thisObj set to the JavaScript 'this' value. funObj is the function object for the invoked function.

When the constructor varargs form is called or invoked while evaluating a new expression, args contains the arguments, ctorObj refers to this FunctionObject, and inNewExpr is true if and only if a new expression caused the call. This supports defining a function that has different behavior when called as a constructor than when invoked as a normal function call. (For example, the Boolean constructor, when called as a function, will convert to boolean rather than creating a new object.)

Parameters:
name - the name of the function
methodOrConstructor - a java.lang.reflect.Method or a java.lang.reflect.Constructor that defines the object
scope - enclosing scope of function
See Also:
Scriptable

Method Details

addAsConstructor

public void addAsConstructor(Scriptable scope,
                             Scriptable prototype)
Define this function as a JavaScript constructor.

Sets up the "prototype" and "constructor" properties. Also calls setParent and setPrototype with appropriate values. Then adds the function object as a property of the given scope, using prototype.getClassName() as the name of the property.

Parameters:
scope - the scope in which to define the constructor (typically the global object)
prototype - the prototype object

call

public Object call(Context cx,
                   Scriptable scope,
                   Scriptable thisObj,
                   Object[] args)
Performs conversions on argument types if needed and invokes the underlying Java method or constructor.

Implements Function.call.

Specified by:
call in interface Function
call in interface Callable
Overrides:
call in interface BaseFunction

convertArg

public static Object convertArg(Context cx,
                                Scriptable scope,
                                Object arg,
                                Class desired)

Deprecated. Use getTypeTag(Class) and convertArg(Context,Scriptable,Object,int) for type convertion.


convertArg

public static Object convertArg(Context cx,
                                Scriptable scope,
                                Object arg,
                                int typeTag)

createObject

public Scriptable createObject(Context cx,
                               Scriptable scope)
Return new Scriptable instance using the default constructor for the class of the underlying Java method. Return null to indicate that the call method should be used to create new objects.
Overrides:
createObject in interface BaseFunction

getArity

public int getArity()
Return the value defined by the method used to construct the object (number of parameters of the method, or 1 if the method is a "varargs" form).
Overrides:
getArity in interface BaseFunction

getFunctionName

public String getFunctionName()
Overrides:
getFunctionName in interface BaseFunction

getLength

public int getLength()
Overrides:
getLength in interface BaseFunction

getMethodOrConstructor

public Member getMethodOrConstructor()
Get Java method or constructor this function represent.

getTypeTag

public static int getTypeTag(Class type)