org.apache.bsf.debug.jsdi

Interface JsObject

All Superinterfaces:

java.rmi.Remote

All Known Subinterfaces:

JsCode, JsFunction, JsScript

All Known Implementing Classes:

JsCodeStub, JsObjectStub, JsObjectStub

public interface JsObject
extends java.rmi.Remote

This is interface that all objects in JavaScript must implement. The interface provides for the management of properties and for performing conversions.

Host system implementors may find it easier to extend the ScriptableObject class rather than implementing Scriptable when writing host objects.

There are many static methods defined in ScriptableObject that perform the multiple calls to the Scriptable interface needed in order to manipulate properties in prototype chains.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DONTDELETE Property attribute indicating property cannot be deleted.
static int	DONTENUM Property attribute indicating property is not enumerated.
static int	EMPTY The empty property attribute.
static int	INTERNAL Property attribute indicating property cannot be deleted.
static int	READONLY Property attribute indicating assignment to this property is ignored.

Method Summary

Methods

Modifier and Type	Method and Description
void	define(java.lang.String propertyName, java.lang.Object value, int attributes) The value can be any of the following type: java.lang.Boolean java.lang.Number java.lang.String org.apache.bsf.debug.jsdi.JsObject
void	delete(int index) Removes a property from this object.
void	delete(java.lang.String name) Removes a property from this object.
java.lang.Object	get(int index)
java.lang.Object	get(java.lang.String name) Get a named property from the object.
java.lang.String	getClassName() Get the name of the set of objects implemented by this Java class.
java.lang.Object	getDefaultValue(java.lang.Class hint) Get the default value of the object with a given hint.
java.lang.Object[]	getIds(boolean all) Returns an array of property ids defined on this object.
JsObject	getPrototype() Get the prototype of the object.
JsObject	getScope() The scope is for supporting two things.
boolean	has(int index) Indicates whether or not an indexed property is defined in an object.
boolean	has(java.lang.String name) Indicates whether or not a named property is defined in an object.
boolean	hasInstance(JsObject instance) The instanceof operator.
boolean	isFunction()
boolean	isScript()
void	put(int index, java.lang.Object value) Sets an indexed property in this object.
void	put(java.lang.String name, java.lang.Object value) Sets a named property in this object.
void	setPrototype(JsObject prototype) Set the prototype of the object.
void	setScope(JsObject scope) Set the prototype of the object.

Field Detail

DONTDELETE

static final int DONTDELETE

Property attribute indicating property cannot be deleted.

See Also:

ScriptableObject.delete(java.lang.String), ScriptableObject.getAttributes(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.setAttributes(java.lang.String, org.mozilla.javascript.Scriptable, int), Constant Field Values

DONTENUM

static final int DONTENUM

Property attribute indicating property is not enumerated. Only enumerated properties will be returned by getIds().

See Also:

ScriptableObject.getIds(), ScriptableObject.getAttributes(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.setAttributes(java.lang.String, org.mozilla.javascript.Scriptable, int), Constant Field Values

EMPTY

static final int EMPTY

The empty property attribute. Used by getAttributes() and setAttributes().

See Also:

ScriptableObject.getAttributes(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.setAttributes(java.lang.String, org.mozilla.javascript.Scriptable, int), Constant Field Values

INTERNAL

static final int INTERNAL

Property attribute indicating property cannot be deleted.

See Also:

ScriptableObject.delete(java.lang.String), ScriptableObject.getAttributes(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.setAttributes(java.lang.String, org.mozilla.javascript.Scriptable, int), Constant Field Values

READONLY

static final int READONLY

Property attribute indicating assignment to this property is ignored.

See Also:

ScriptableObject.put(java.lang.String, org.mozilla.javascript.Scriptable, java.lang.Object), ScriptableObject.getAttributes(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.setAttributes(java.lang.String, org.mozilla.javascript.Scriptable, int), Constant Field Values

Method Detail

define

void define(java.lang.String propertyName,
          java.lang.Object value,
          int attributes)
            throws java.rmi.RemoteException

The value can be any of the following type: java.lang.Boolean java.lang.Number java.lang.String org.apache.bsf.debug.jsdi.JsObject

Throws:

java.rmi.RemoteException

delete

void delete(int index)
            throws java.rmi.RemoteException

Removes a property from this object. The prototype chain is not walked to find the property. This operation corresponds to the ECMA [[Delete]] except that the no result is returned. The runtime will guarantee that this method is called only if the property exists. After this method is called, the runtime will call Scriptable.has to see if the property has been removed in order to determine the boolean result of the delete operator as defined by ECMA 11.4.1.

A property can be made permanent by ignoring calls to remove it. The property is specified by an integral index as defined for get.

To delete properties defined in a prototype chain, first find the owner object of the property and then call deleteProperty on that owner object. Identical to delete(String) except that an integral index is used to select the property.

Parameters:

index - the numeric index for the property

Throws:

java.rmi.RemoteException

See Also:

Scriptable.get(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.deleteProperty(org.mozilla.javascript.Scriptable, java.lang.String)

delete

void delete(java.lang.String name)
            throws java.rmi.RemoteException

Removes a property from this object. This operation corresponds to the ECMA [[Delete]] except that the no result is returned. The runtime will guarantee that this method is called only if the property exists. After this method is called, the runtime will call Scriptable.has to see if the property has been removed in order to determine the boolean result of the delete operator as defined by ECMA 11.4.1.

A property can be made permanent by ignoring calls to remove it.

The property is specified by a String name as defined for get.

To delete properties defined in a prototype chain, first find the owner object of the property and then call deleteProperty on that owner object.

Parameters:

name - the identifier for the property

Throws:

java.rmi.RemoteException

See Also:

Scriptable.get(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.deleteProperty(org.mozilla.javascript.Scriptable, java.lang.String)

get

java.lang.Object get(java.lang.String name)
                     throws java.rmi.RemoteException

Get a named property from the object. Does not walk the prototype chain. Looks property up in this object and returns the associated value if found. Returns NOT_FOUND if not found. Note that this method is not expected to traverse the prototype chain. This is different from the ECMA [[Get]] operation. Depending on the property selector, the runtime will call this method or the form of get that takes an integer:

JavaScript code	Java code
a.b	a.get("b", a)
a["foo"]	a.get("foo", a)
a[3]	a.get(3, a)
a["3"]	a.get(3, a)
a[3.0]	a.get(3, a)
a["3.0"]	a.get("3.0", a)
a[1.1]	a.get("1.1", a)
a[-4]	a.get(-4, a)

The values that may be returned are limited to the following:

• java.lang.Boolean objects
• java.lang.String objects
• java.lang.Number objects
• org.apache.bsf.debug.jsdi.JsObject objects
• null
• The value returned by Context.getUndefinedValue()
• NOT_FOUND

Parameters:

name - the name of the property

Returns:

the value of the property (may be null), or NOT_FOUND

Throws:

java.rmi.RemoteException

get

java.lang.Object get(int index)
                     throws java.rmi.RemoteException

Throws:

java.rmi.RemoteException

getClassName

java.lang.String getClassName()
                              throws java.rmi.RemoteException

Get the name of the set of objects implemented by this Java class. This corresponds to the [[Class]] operation in ECMA and is used by Object.prototype.toString() in ECMA.

See ECMA 8.6.2 and 15.2.4.2.

Throws:

java.rmi.RemoteException

getDefaultValue

java.lang.Object getDefaultValue(java.lang.Class hint)
                                 throws java.rmi.RemoteException

Get the default value of the object with a given hint. The hints are String.class for type String, Number.class for type Number, Scriptable.class for type Object, and Boolean.class for type Boolean.

A hint of null means "no hint". See ECMA 8.6.2.6.

Parameters:

hint - the type hint

Returns:

the default value

Throws:

java.rmi.RemoteException

getIds

java.lang.Object[] getIds(boolean all)
                          throws java.rmi.RemoteException

Returns an array of property ids defined on this object. The prototype chain is not walked. However, modified properties that were prototype properties will be seen. The parameter indicates to enumerate the "DONTENUM" properties or not.

Returns:

an array of all ids from all object in the prototype chain. If a given id occurs multiple times in the prototype chain, it will occur only once in this list. The elements are limited to: - java.lang.String for the property name if it has one. - java.lang.Integer for properties without a name, it is their index.

Throws:

java.rmi.RemoteException

Since:

1.5R2

getPrototype

JsObject getPrototype()
                      throws java.rmi.RemoteException

Get the prototype of the object.

Returns:

the prototype

Throws:

java.rmi.RemoteException

getScope

JsObject getScope()
                  throws java.rmi.RemoteException

The scope is for supporting two things. If the object is a function, the scope is the "execution" scope of the function. It will be used when calling the function to initialize the Context scope. If the object is not a function, the scope is used for the scope chain of execution context.

Throws:

java.rmi.RemoteException

has

boolean has(int index)
            throws java.rmi.RemoteException

Indicates whether or not an indexed property is defined in an object. Does not traverse the prototype chain.

The property is specified by an integral index as defined for the get method.

Parameters:

index - the numeric index for the property

Returns:

true if and only if the indexed property is found in the object

Throws:

java.rmi.RemoteException

See Also:

Scriptable.get(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.getProperty(org.mozilla.javascript.Scriptable, java.lang.String)

has

boolean has(java.lang.String name)
            throws java.rmi.RemoteException

Indicates whether or not a named property is defined in an object. Does not traverse the prototype chain.

The property is specified by a String name as defined for the get method.

Parameters:

name - the name of the property

Returns:

true if and only if the named property is found in the object

Throws:

java.rmi.RemoteException

See Also:

Scriptable.get(java.lang.String, org.mozilla.javascript.Scriptable), ScriptableObject.getProperty(org.mozilla.javascript.Scriptable, java.lang.String)

hasInstance

boolean hasInstance(JsObject instance)
                    throws java.rmi.RemoteException

The instanceof operator.

The JavaScript code "lhs instanceof rhs" causes rhs.hasInstance(lhs) to be called.

The return value is implementation dependent so that embedded host objects can return an appropriate value. See the JS 1.3 language documentation for more detail.

This operator corresponds to the proposed EMCA [[HasInstance]] operator.

Parameters:

instance - The value that appeared on the LHS of the instanceof operator

Returns:

an implementation dependent value

Throws:

java.rmi.RemoteException

isFunction

boolean isFunction()
                   throws java.rmi.RemoteException

Throws:

java.rmi.RemoteException

isScript

boolean isScript()
                 throws java.rmi.RemoteException

Throws:

java.rmi.RemoteException

put

void put(int index,
       java.lang.Object value)
         throws java.rmi.RemoteException

Sets an indexed property in this object.

The property is specified by an integral index as defined for get.

Parameters:

index - the numeric index for the property

value - value to set the property to

Throws:

java.rmi.RemoteException

put

void put(java.lang.String name,
       java.lang.Object value)
         throws java.rmi.RemoteException

Sets a named property in this object.

The property is specified by a string name as defined for get.

Note that if a property a is defined in the prototype p of an object o, then evaluating o.a = 23 will cause set to be called on the prototype p with o as the start parameter. To preserve JavaScript semantics, it is the Scriptable object's responsibility to modify o.

This design allows properties to be defined in prototypes and implemented in terms of getters and setters of Java values without consuming slots in each instance.

The values that may be set are limited to the following:

• java.lang.Boolean objects
• java.lang.String objects
• java.lang.Number objects
• org.apache.bsf.debug.jsdi.JsObject
• null
• The value returned by Context.getUndefinedValue()

IMPORTANT: JAVA OBJECTS. The wrapping is not yet supported.

Throws:

java.rmi.RemoteException

setPrototype

void setPrototype(JsObject prototype)
                  throws java.rmi.RemoteException

Set the prototype of the object.

Parameters:

prototype - the prototype to set

Throws:

java.rmi.RemoteException

setScope

void setScope(JsObject scope)
              throws java.rmi.RemoteException

Set the prototype of the object.

Parameters:

prototype - the prototype to set

Throws:

java.rmi.RemoteException