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KJS::Object Class Reference

#include <object.h>

Inheritance diagram for KJS::Object:

KJS::Value List of all members.

Public Methods

Value prototype () const
UString className () const
Value get (ExecState *exec, const UString &propertyName) const
void put (ExecState *exec, const UString &propertyName, const Value &value, int attr=None)
bool canPut (ExecState *exec, const UString &propertyName) const
bool hasProperty (ExecState *exec, const UString &propertyName) const
bool deleteProperty (ExecState *exec, const UString &propertyName)
Value defaultValue (ExecState *exec, Type hint) const
bool implementsConstruct () const
Object construct (ExecState *exec, const List &args)
bool implementsCall () const
Value call (ExecState *exec, Object &thisObj, const List &args)
bool implementsHasInstance () const
Boolean hasInstance (ExecState *exec, const Value &value)
const List scope () const
List propList (ExecState *exec, bool recursive=true)
Value internalValue () const
void setInternalValue (const Value &v)

Static Public Methods

Object dynamicCast (const Value &v)

Detailed Description

Represents an Object. This is a wrapper for ObjectImp

Definition at line 76 of file object.h.

Member Function Documentation

Value KJS::Object::call (  ExecState *    exec,
Object &    thisObj,
const List &    args
) 
 

Calls this object as if it is a function.

Note: This function should not be called if implementsCall() returns false, in which case it will result in an assertion failure.

See ECMA 8.6.2.3

Parameters:
exec  The current execution state
thisObj  The obj to be used as "this" within function execution. Note that in most cases this will be different from the C++ "this" object. For example, if the ECMAScript code "window.location.toString()" is executed, call() will be invoked on the C++ object which implements the toString method, with the thisObj being window.location
args  List of arguments to be passed to the function
Returns:
The return value from the function

bool KJS::Object::canPut (  ExecState *    exec,
const UString &    propertyName
)  const
 

Used to check whether or not a particular property is allowed to be set on an object

See ECMA 8.6.2.3

Parameters:
exec  The current execution state
propertyName  The name of the property
Returns:
true if the property can be set, otherwise false

UString KJS::Object::className (    ) 
 

Returns the class name of the object

See ECMA 8.6.2

Returns:
The object's class name

Object KJS::Object::construct (  ExecState *    exec,
const List &    args
) 
 

Creates a new object based on this object. Typically this means the following: 1. A new object is created 2. The prototype of the new object is set to the value of this object's "prototype" property 3. The call() method of this object is called, with the new object passed as the this value 4. The new object is returned

In some cases, Host objects may differ from these semantics, although this is discouraged.

If an error occurs during construction, the execution state's exception will be set. This can be tested for with ExecState::hadException(). Under some circumstances, the exception object may also be returned.

Note: This function should not be called if implementsConstruct() returns false, in which case it will result in an assertion failure.

Parameters:
exec  The current execution state
args  The arguments to be passed to call() once the new object has been created
Returns:
The newly created & initialized object

Value KJS::Object::defaultValue (  ExecState *    exec,
Type    hint
)  const
 

Converts the object into a primitive value. The value return may differ depending on the supplied hint

See ECMA 8.6.2.6

Parameters:
exec  The current execution state
hint  The desired primitive type to convert to
Returns:
A primitive value converted from the objetc. Note that the type of primitive value returned may not be the same as the requested hint.

bool KJS::Object::deleteProperty (  ExecState *    exec,
const UString &    propertyName
) 
 

Removes the specified property from the object.

See ECMA 8.6.2.5

Parameters:
exec  The current execution state
propertyName  The name of the property to delete
Returns:
true if the property was successfully deleted or did not exist on the object. false if deleting the specified property is not allowed.

Object KJS::Object::dynamicCast (  const Value &    v )  [static]
 

Converts a Value into an Object. If the value's type is not ObjectType, a null object will be returned (i.e. one with it's internal pointer set to 0). If you do not know for sure whether the value is of type ObjectType, you should check the isNull() methods afterwards before calling any methods on the Object.

Returns:
The value converted to an object

Value KJS::Object::get (  ExecState *    exec,
const UString &    propertyName
)  const
 

Retrieves the specified property from the object. If neither the object or any other object in it's prototype chain have the property, this function will return Undefined.

See ECMA 8.6.2.1

Parameters:
exec  The current execution state
propertyName  The name of the property to retrieve
Returns:
The specified property, or Undefined

Boolean KJS::Object::hasInstance (  ExecState *    exec,
const Value &    value
) 
 

Checks whether value delegates behaviour to this object. Used by the instanceof operator.

Parameters:
exec  The current execution state
value  The value to check
Returns:
true if value delegates behaviour to this object, otherwise false

bool KJS::Object::hasProperty (  ExecState *    exec,
const UString &    propertyName
)  const
 

Checks to see whether the object (or any object in it's prototype chain) has a property with the specified name.

See ECMA 8.6.2.4

Parameters:
exec  The current execution state
propertyName  The name of the property to check for
Returns:
true if the object has the property, otherwise false

bool KJS::Object::implementsCall (    ) 
 

Whether or not the object implements the call() method. If this returns false you should not call the call() method on this object (typically, an assertion will fail to indicate this).

Returns:
true if this object implements the call() method, otherwise false

bool KJS::Object::implementsConstruct (    ) 
 

Whether or not the object implements the construct() method. If this returns false you should not call the construct() method on this object (typically, an assertion will fail to indicate this).

Returns:
true if this object implements the construct() method, otherwise false

bool KJS::Object::implementsHasInstance (    ) 
 

Whether or not the object implements the hasInstance() method. If this returns false you should not call the hasInstance() method on this object (typically, an assertion will fail to indicate this).

Returns:
true if this object implements the hasInstance() method, otherwise false

Value KJS::Object::internalValue (    ) 
 

Returns the internal value of the object. This is used for objects such as String and Boolean which are wrappers for native types. The interal value is the actual value represented by the wrapper objects.

See also:
ECMA 8.6.2
Returns:
The internal value of the object

List KJS::Object::propList (  ExecState *    exec,
bool    recursive = true
) 
 

Returns a List of References to all the properties of the object. Used in "for x in y" statements. The list is created new, so it can be freely modified without affecting the object's properties. It should be deleted by the caller.

Subclasses can override this method in ObjectImpl to provide the appearance of having extra properties other than those set specifically with put().

Parameters:
exec  The current execution state
recursive  Whether or not properties in the object's prototype chain should be included in the list.
Returns:
A List of References to properties of the object.

Value KJS::Object::prototype (    ) 
 

Returns the prototype of this object. Note that this is not the same as the "prototype" property.

See ECMA 8.6.2

Returns:
The object's prototype

void KJS::Object::put (  ExecState *    exec,
const UString &    propertyName,
const Value &    value,
int    attr = None
) 
 

Sets the specified property.

See ECMA 8.6.2.2

Parameters:
exec  The current execution state
propertyName  The name of the property to set
propertyValue  The value to set

const List KJS::Object::scope (    ) 
 

Returns the scope of this object. This is used when execution declared functions - the execution context for the function is initialized with extra object in it's scope. An example of this is functions declared inside other functions:

function f() {

function b() { return prototype; }

var x = 4; // do some stuff } f.prototype = new String();

When the function f.b is executed, its scope will include properties of f. So in the example above the return value of f.b() would be the new String object that was assigned to f.prototype.

Parameters:
exec  The current execution state
Returns:
The function's scope

void KJS::Object::setInternalValue (  const Value &    v ) 
 

Sets the internal value of the object

See also:
internalValue()
Parameters:
v  The new internal value

The documentation for this class was generated from the following file:
Generated on Wed Aug 13 23:30:34 2003 for kdelibs by doxygen1.2.18