org.mozilla.javascript
Class FunctionObject

java.lang.Object
  |
  +--org.mozilla.javascript.ScriptableObject
        |
        +--org.mozilla.javascript.IdScriptable
              |
              +--org.mozilla.javascript.BaseFunction
                    |
                    +--org.mozilla.javascript.FunctionObject
All Implemented Interfaces:
org.mozilla.javascript.debug.DebuggableObject, Function, org.mozilla.javascript.IdFunctionMaster, Scriptable, java.io.Serializable

public class FunctionObject
extends org.mozilla.javascript.BaseFunction

See Also:
Serialized Form

Fields inherited from class org.mozilla.javascript.ScriptableObject
DONTENUM, EMPTY, PERMANENT, READONLY
 
Fields inherited from interface org.mozilla.javascript.Scriptable
NOT_FOUND
 
Constructor Summary
FunctionObject(java.lang.String name, java.lang.reflect.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.
 java.lang.Object call(Context cx, Scriptable scope, Scriptable thisObj, java.lang.Object[] args)
          Performs conversions on argument types if needed and invokes the underlying Java method or constructor.
 Scriptable construct(Context cx, Scriptable scope, java.lang.Object[] args)
          Performs conversions on argument types if needed and invokes the underlying Java method or constructor to create a new Scriptable object.
static java.lang.Object convertArg(Context cx, Scriptable scope, java.lang.Object arg, java.lang.Class desired)
           
static java.lang.reflect.Method[] findMethods(java.lang.Class clazz, java.lang.String name)
          Finds methods of a given name in a given class.
 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).
 int getLength()
          Return the same value as getArity().
 
Methods inherited from class org.mozilla.javascript.BaseFunction
createObject, decompile, execMethod, getClassName, getFunctionName, hasInstance, methodArity, setImmunePrototypeProperty
 
Methods inherited from class org.mozilla.javascript.IdScriptable
addAsPrototype, defineProperty, delete, get, getAttributes, has, put, setAttributes
 
Methods inherited from class org.mozilla.javascript.ScriptableObject
callMethod, defineClass, defineClass, defineFunctionProperties, defineProperty, defineProperty, defineProperty, delete, deleteProperty, deleteProperty, get, getAllIds, getAttributes, getClassPrototype, getDefaultValue, getFunctionPrototype, getIds, getObjectPrototype, getParentScope, getProperty, getProperty, getPropertyIds, getPrototype, getTopLevelScope, has, hasProperty, hasProperty, isSealed, put, putProperty, putProperty, sealObject, setAttributes, setParentScope, setPrototype
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.mozilla.javascript.Scriptable
delete, delete, get, get, getDefaultValue, getIds, getParentScope, getPrototype, has, has, put, put, setParentScope, setPrototype
 

Constructor Detail

FunctionObject

public FunctionObject(java.lang.String name,
                      java.lang.reflect.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, byte, short, int, float, 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 Detail

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 class org.mozilla.javascript.BaseFunction

getLength

public int getLength()
Return the same value as getArity().
Overrides:
getLength in class org.mozilla.javascript.BaseFunction

findMethods

public static java.lang.reflect.Method[] findMethods(java.lang.Class clazz,
                                                     java.lang.String name)
Finds methods of a given name in a given class.

Searches clazz for methods with name name. Maintains a cache so that multiple lookups on the same class are cheap.

Parameters:
clazz - the class to search
name - the name of the methods to find
Returns:
an array of the found methods, or null if no methods by that name were found.
See Also:
Class.getMethods()

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
See Also:
Scriptable.setParentScope(org.mozilla.javascript.Scriptable), Scriptable.setPrototype(org.mozilla.javascript.Scriptable), Scriptable.getClassName()

convertArg

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

call

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

Implements Function.call.

Overrides:
call in class org.mozilla.javascript.BaseFunction
Throws:
JavaScriptException - if the underlying Java method or constructor threw an exception
See Also:
Function.call(org.mozilla.javascript.Context, org.mozilla.javascript.Scriptable, org.mozilla.javascript.Scriptable, java.lang.Object[])

construct

public Scriptable construct(Context cx,
                            Scriptable scope,
                            java.lang.Object[] args)
                     throws JavaScriptException
Performs conversions on argument types if needed and invokes the underlying Java method or constructor to create a new Scriptable object.

Implements Function.construct.

Overrides:
construct in class org.mozilla.javascript.BaseFunction
Parameters:
cx - the current Context for this thread
scope - the scope to execute the function relative to. This set to the value returned by getParentScope() except when the function is called from a closure.
args - arguments to the constructor
Throws:
JavaScriptException - if the underlying Java method or constructor threw an exception
See Also:
Function.construct(org.mozilla.javascript.Context, org.mozilla.javascript.Scriptable, java.lang.Object[])