# kjs Library API Documentation

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# KJS::Object Class Reference

Represents an Object. More...

`#include <object.h>`

Inheritance diagram for KJS::Object:

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Collaboration diagram for KJS::Object:

[legend]
List of all members.

## Public Member Functions

| Object (ObjectImp *v)
| Object (const Object &v)
Object & | operator= (const Object &v)
virtual const ClassInfo * | classInfo () const
bool | inherits (const ClassInfo *cinfo) const
Value | prototype () const
| Returns the prototype of this object.
UString | className () const
| Returns the class name of the object.
Value | get (ExecState *exec, const UString &propertyName) const
| Retrieves the specified property from the object.
void | put (ExecState *exec, const UString &propertyName, const Value &value, int attr=None)
| Sets the specified property.
bool | canPut (ExecState *exec, const UString &propertyName) const
| Used to check whether or not a particular property is allowed to be set on an object.
bool | 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.
bool | deleteProperty (ExecState *exec, const UString &propertyName)
| Removes the specified property from the object.
Value | defaultValue (ExecState *exec, Type hint) const
| Converts the object into a primitive value.
bool | implementsConstruct () const
| Whether or not the object implements the construct() method.
Object | construct (ExecState *exec, const List &args)
| Creates a new object based on this object.
bool | implementsCall () const
| Whether or not the object implements the call() method.
Value | call (ExecState *exec, Object &thisObj, const List &args)
| Calls this object as if it is a function.
bool | implementsHasInstance () const
| Whether or not the object implements the hasInstance() method.
Boolean | hasInstance (ExecState *exec, const Value &value)
| Checks whether value delegates behaviour to this object.
const List | scope () const
| Returns the scope of this object.
void | setScope (const List &s)
List | propList (ExecState *exec, bool recursive=true)
| Returns a List of References to all the properties of the object.
Value | internalValue () const
| Returns the internal value of the object.
void | setInternalValue (const Value &v)
| Sets the internal value of the object.

## Static Public Member Functions

Object | dynamicCast (const Value &v)
| Converts a Value into an Object.

## Detailed Description

Represents an Object.

This is a wrapper for ObjectImp

Definition at line 76 of file object.h.

## Member Function Documentation

Object 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

Definition at line 77 of file object.cpp.

References KJS::Value::imp(), KJS::Value::isNull(), and KJS::Value::type().

Value Object::prototype | ( |  | ) | const

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

Definition at line 85 of file object.cpp.

UString Object::className | ( |  | ) | const

Returns the class name of the object.

See ECMA 8.6.2

Returns:
  The object's class name

Definition at line 90 of file object.cpp.

Value 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

Definition at line 95 of file object.cpp.

void 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

Definition at line 100 of file object.cpp.

Referenced by KJS::Error::create().

bool 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

Definition at line 105 of file object.cpp.

bool 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

Definition at line 110 of file object.cpp.

bool 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.

Definition at line 115 of file object.cpp.

Value 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.

Definition at line 120 of file object.cpp.

bool Object::implementsConstruct | ( |  | ) | const

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

Definition at line 125 of file object.cpp.

Object 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

Definition at line 130 of file object.cpp.

Referenced by KJS::Error::create().

bool Object::implementsCall | ( |  | ) | const

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

Definition at line 135 of file object.cpp.

Value 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

Definition at line 140 of file object.cpp.

References KJS::ExecState::setException().

bool Object::implementsHasInstance | ( |  | ) | const

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

Definition at line 164 of file object.cpp.

Boolean 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

Definition at line 169 of file object.cpp.

const List Object::scope | ( |  | ) | const

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

Definition at line 174 of file object.cpp.

List 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.

Definition at line 184 of file object.cpp.

Value Object::internalValue | ( |  | ) | const

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

Definition at line 189 of file object.cpp.

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

Sets the internal value of the object.

See also:
  internalValue()

Parameters:

  v | The new internal value

Definition at line 194 of file object.cpp.

The documentation for this class was generated from the following files:

- object.h
- object.cpp

This file is part of the documentation for kdelibs Version 3.1.5.
Documentation copyright © 1996-2002 the KDE developers.
Generated on Wed Jan 28 13:09:15 2004 by doxygen 1.3.4 written by Dimitri van Heesch, © 1997-2001