\inmodule QtQml More...

#include <qjsmanagedvalue.h>

Collaboration diagram for QJSManagedValue:

Public Types
enum	Type { Undefined , Boolean , Number , String , Object , Symbol , Function }
	This enum represents the JavaScript native types, as specified by \l{ECMA-262}. More...

Public Member Functions
	QJSManagedValue ()=default
	Creates a QJSManagedValue that represents the JavaScript `undefined` value.

	QJSManagedValue (QJSValue value, QJSEngine *engine)
	Creates a QJSManagedValue from value, using the heap of engine.

	QJSManagedValue (const QJSPrimitiveValue &value, QJSEngine *engine)
	Creates a QJSManagedValue from value using the heap of engine.

	QJSManagedValue (const QVariant &variant, QJSEngine *engine)
	Creates a QJSManagedValue from variant using the heap of engine.

	QJSManagedValue (const QString &string, QJSEngine *engine)
	Creates a QJSManagedValue from string using the heap of engine.

	~QJSManagedValue ()
	Destroys the QJSManagedValue.

	QJSManagedValue (QJSManagedValue &&other)
	Move-constructs a QJSManagedValue from other.

QJSManagedValue &	operator= (QJSManagedValue &&other)
	Move-assigns a QJSManagedValue from other.

bool	equals (const QJSManagedValue &other) const
	Invokes the JavaScript '==' operator on this QJSManagedValue and other, and returns the result.

bool	strictlyEquals (const QJSManagedValue &other) const
	Invokes the JavaScript '===' operator on this QJSManagedValue and other, and returns the result.

QJSEngine *	engine () const
	Returns the QJSEngine this QJSManagedValue belongs to.

QJSManagedValue	prototype () const
	Returns the prototype for this QJSManagedValue.

void	setPrototype (const QJSManagedValue &prototype)
	Sets the prototype of this QJSManagedValue to prototype.

Type	type () const
	Returns the JavaScript type of this QJSManagedValue.

bool	isUndefined () const
	Returns `true` if the type of this QJSManagedValue is `undefined`, or `false` otherwise.

bool	isBoolean () const
	Returns `true` if the type of this QJSManagedValue is `boolean`, or `false` otherwise.

bool	isNumber () const
	Returns `true` if the type of this QJSManagedValue is `number`, or `false` otherwise.

bool	isString () const
	Returns `true` if the type of this QJSManagedValue is `string`, or `false` otherwise.

bool	isObject () const
	Returns `true` if the type of this QJSManagedValue is `object`, or `false` otherwise.

bool	isSymbol () const
	Returns `true` if the type of this QJSManagedValue is `symbol`, or `false` otherwise.

bool	isFunction () const
	Returns `true` if the type of this QJSManagedValue is `function`, `false` otherwise.

bool	isInteger () const
	Returns `true` if this QJSManagedValue holds an integer value, or `false` otherwise.

bool	isNull () const
	Returns `true` if this QJSManagedValue holds the JavaScript `null` value, or `false` otherwise.

bool	isRegularExpression () const
	Returns `true` if this value represents a JavaScript regular expression object, or `false` otherwise.

bool	isArray () const
	Returns `true` if this value represents a JavaScript Array object, or `false` otherwise.

bool	isUrl () const
	Returns `true` if this value represents a JavaScript Url object, or `false` otherwise.

bool	isVariant () const
	Returns `true` if this value represents a QVariant managed on the JavaScript heap, or `false` otherwise.

bool	isQObject () const
	Returns `true` if this value represents a QObject pointer managed on the JavaScript heap, or `false` otherwise.

bool	isQMetaObject () const
	Returns `true` if this value represents a QMetaObject pointer managed on the JavaScript heap, or `false` otherwise.

bool	isDate () const
	Returns `true` if this value represents a JavaScript Date object, or `false` otherwise.

bool	isError () const
	Returns `true` if this value represents a JavaScript Error object, or `false` otherwise.

bool	isJsMetaType () const

QString	toString () const
	Converts the manged value to a string.

double	toNumber () const
	Converts the manged value to a number.

bool	toBoolean () const
	Converts the manged value to a boolean.

QJSPrimitiveValue	toPrimitive () const
	Converts the manged value to a QJSPrimitiveValue.

QJSValue	toJSValue () const
	Copies this QJSManagedValue into a new QJSValue.

QVariant	toVariant () const
	Copies this QJSManagedValue into a new QVariant.

int	toInteger () const
	Converts the manged value to an integer.

QRegularExpression	toRegularExpression () const
	If this QJSManagedValue holds a JavaScript regular expression object, returns an equivalent QRegularExpression.

QUrl	toUrl () const
	If this QJSManagedValue holds a JavaScript Url object, returns an equivalent QUrl.

QObject *	toQObject () const
	If this QJSManagedValue holds a QObject pointer, returns it.

const QMetaObject *	toQMetaObject () const
	If this QJSManagedValue holds a QMetaObject pointer, returns it.

QDateTime	toDateTime () const
	If this QJSManagedValue holds a JavaScript Date object, returns an equivalent QDateTime.

bool	hasProperty (const QString &name) const
	Returns `true` if this QJSManagedValue has a property name, otherwise returns `false`.

bool	hasOwnProperty (const QString &name) const
	Returns `true` if this QJSManagedValue has a property name, otherwise returns `false`.

QJSValue	property (const QString &name) const
	Returns the property name of this QJSManagedValue.

void	setProperty (const QString &name, const QJSValue &value)
	Sets the property name to value on this QJSManagedValue.

bool	deleteProperty (const QString &name)
	Deletes the property name from this QJSManagedValue.

bool	hasProperty (quint32 arrayIndex) const
	Returns `true` if this QJSManagedValue has an array index arrayIndex, otherwise returns `false`.

bool	hasOwnProperty (quint32 arrayIndex) const
	Returns `true` if this QJSManagedValue has an array index arrayIndex, otherwise returns `false`.

QJSValue	property (quint32 arrayIndex) const
	Returns the property stored at arrayIndex of this QJSManagedValue.

void	setProperty (quint32 arrayIndex, const QJSValue &value)
	Stores the value at arrayIndex in this QJSManagedValue.

bool	deleteProperty (quint32 arrayIndex)
	Deletes the value stored at arrayIndex from this QJSManagedValue.

QJSValue	call (const QJSValueList &arguments={}) const
	If this QJSManagedValue represents a JavaScript FunctionObject, calls it with the given arguments, and returns the result.

QJSValue	callWithInstance (const QJSValue &instance, const QJSValueList &arguments={}) const
	If this QJSManagedValue represents a JavaScript FunctionObject, calls it on instance with the given arguments, and returns the result.

QJSValue	callAsConstructor (const QJSValueList &arguments={}) const
	If this QJSManagedValue represents a JavaScript FunctionObject, calls it as constructor with the given arguments, and returns the result.

QJSManagedValue	jsMetaType () const

QStringList	jsMetaMembers () const

QJSManagedValue	jsMetaInstantiate (const QJSValueList &values={}) const

Friends
class	QJSValue

class	QJSEngine

Detailed Description

\inmodule QtQml

Since: 6.1

\inmodule QtQml

QJSManagedValue represents a value on the JavaScript heap belonging to a QJSEngine.

The QJSManagedValue class allows interaction with JavaScript values in most ways you can interact with them from JavaScript itself. You can get and set properties and prototypes, and you can access arrays. Additionally, you can transform the value into the Qt counterparts of JavaScript objects. For example, a Url object may be transformed into a QUrl.

A QJSManagedValue is always bound to a particular QJSEngine. You cannot use it independently. This means that you cannot have a QJSManagedValue from one engine be a property or a proptotype of a QJSManagedValue from a different engine.

In contrast to QJSValue, almost all values held by QJSManagedValue live on the JavaScript heap. There is no inline or unmanaged storage. Therefore, you can get the prototype of a primitive value, and you can get the length property of a string.

Only default-constructed or moved-from QJSManagedValues do not hold a value on the JavaScript heap. They represent undefined, which doesn't have any properties or prototypes.

Also in contrast to QJSValue, QJSManagedValue does not catch any JavaScript exceptions. If an operation on a QJSManagedValue causes an error, it will generally return an undefined value and QJSEngine::hasError() will return true afterwards. You can then catch the exception using QJSEngine::catchError(), or pass it up the stack, at your own discretion.

Note: As the reference to the value on the JavaScript heap has to be freed on destruction, you cannot move a QJSManagedValue to a different thread. The destruction would take place in the new thread, which would create a race condition with the garbage collector on the original thread. This also means that you cannot hold a QJSManagedValue beyond the lifespan of its engine.

The recommended way of working with a QJSManagedValue is creating it on the stack, possibly by moving a QJSValue and adding an engine, then performing the necessary operations on it, and finally moving it back into a QJSValue for storage. Moving between QJSManagedValue and QJSValue is fast.

Definition at line 19 of file qjsmanagedvalue.h.

Member Enumeration Documentation

◆ Type

enum QJSManagedValue::Type

This enum represents the JavaScript native types, as specified by \l{ECMA-262}.

\value Undefined The undefined type \value Boolean The boolean type \value Number The number type \value String The string type \value Object The object type \value Symbol The symbol type \value Function The function type

Note that the null value is not a type of itself but rather a special kind of object. You can query a QJSManagedValue for this condition using the isNull() method. Furthermore, JavaScript has no integer type, but it knows a special treatment of numbers in preparation for integer only operations. You can query a QJSManagedValue to find out whether it holds the result of such a treatment by using the isInteger() method.

Enumerator
Undefined
Boolean
Number
String
Object
Symbol
Function

Definition at line 23 of file qjsmanagedvalue.h.

Constructor & Destructor Documentation

◆ QJSManagedValue() [1/6]

QJSManagedValue::QJSManagedValue ( )

default

Creates a QJSManagedValue that represents the JavaScript undefined value.

This is the only value not stored on the JavaScript heap. Calling engine() on a default-constructed QJSManagedValue will return nullptr.

Referenced by jsMetaInstantiate(), jsMetaType(), and prototype().

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◆ QJSManagedValue() [2/6]

QJSManagedValue::QJSManagedValue	(	QJSValue	value,
		QJSEngine *	engine )

Creates a QJSManagedValue from value, using the heap of engine.

If value is itself managed and the engine it belongs to is not engine, the result is an undefined value, and a warning is generated.

Definition at line 120 of file qjsmanagedvalue.cpp.

References QV4::PersistentValueStorage::allocate(), QJSValuePrivate::asQString(), QJSValuePrivate::asReturnedValue(), engine(), QV4::PersistentValueStorage::free(), QJSEngine::handle(), QV4::MemoryManager::m_persistentValues, QV4::EngineBase::memoryManager, QV4::ExecutionEngine::newString(), Q_UNLIKELY, qWarning, QJSValuePrivate::takeManagedValue(), and v4Engine().

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◆ QJSManagedValue() [3/6]

QJSManagedValue::QJSManagedValue	(	const QJSPrimitiveValue &	value,
		QJSEngine *	engine )

Creates a QJSManagedValue from value using the heap of engine.

Definition at line 147 of file qjsmanagedvalue.cpp.

References QJSPrimitiveValue::Boolean, QJSPrimitiveValue::Double, engine(), QJSEngine::handle(), QJSPrimitiveValue::Integer, QV4::ExecutionEngine::newString(), QV4::Encode::null(), QJSPrimitiveValue::Null, QJSPrimitiveValue::String, QV4::Encode::undefined(), and QJSPrimitiveValue::Undefined.

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◆ QJSManagedValue() [4/6]

QJSManagedValue::QJSManagedValue	(	const QVariant &	variant,
		QJSEngine *	engine )

Creates a QJSManagedValue from variant using the heap of engine.

Definition at line 177 of file qjsmanagedvalue.cpp.

References engine(), QV4::ExecutionEngine::fromVariant(), QJSEngine::handle(), and variant.

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◆ QJSManagedValue() [5/6]

QJSManagedValue::QJSManagedValue	(	const QString &	string,
		QJSEngine *	engine )

Creates a QJSManagedValue from string using the heap of engine.

Definition at line 186 of file qjsmanagedvalue.cpp.

References engine(), QJSEngine::handle(), and QV4::ExecutionEngine::newString().

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◆ ~QJSManagedValue()

QJSManagedValue::~QJSManagedValue ( )

Destroys the QJSManagedValue.

Note: This frees the memory slot it holds on the JavaScript heap. You must not destroy a QJSManagedValue from a different thread than the one where the QJSEngine it belongs to lives.

Definition at line 199 of file qjsmanagedvalue.cpp.

References QV4::PersistentValueStorage::free().

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◆ QJSManagedValue() [6/6]

QJSManagedValue::QJSManagedValue ( QJSManagedValue && other )

Move-constructs a QJSManagedValue from other.

This leaves other in the default-constructed state where it represents undefined and does not belong to any engine.

Definition at line 209 of file qjsmanagedvalue.cpp.

References other(), and qSwap().

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Member Function Documentation

◆ call()

QJSValue QJSManagedValue::call ( const QJSValueList & arguments = {} ) const

If this QJSManagedValue represents a JavaScript FunctionObject, calls it with the given arguments, and returns the result.

Otherwise returns a JavaScript undefined value.

The arguments have to be either primitive values or belong to the same QJSEngine as this QJSManagedValue. Otherwise the call is not carried out and a JavaScript undefined value is returned.

Definition at line 952 of file qjsmanagedvalue.cpp.

References arg, arguments, QJSValuePrivate::checkEngine(), QJSValuePrivate::convertToReturnedValue(), engine(), QJSValuePrivate::fromReturnedValue(), functionObjectForCall(), QJSEngine::globalObject(), i, Q_UNLIKELY, QJSValue, qWarning, and QList< T >::size().

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◆ callAsConstructor()

QJSValue QJSManagedValue::callAsConstructor ( const QJSValueList & arguments = {} ) const

If this QJSManagedValue represents a JavaScript FunctionObject, calls it as constructor with the given arguments, and returns the result.

Otherwise returns a JavaScript undefined value.

The arguments have to be either primitive values or belong to the same QJSEngine as this QJSManagedValue. Otherwise the call is not carried out and a JavaScript undefined value is returned.

Definition at line 1024 of file qjsmanagedvalue.cpp.

References arg, arguments, QJSValuePrivate::checkEngine(), QJSValuePrivate::convertToReturnedValue(), engine(), QJSValuePrivate::fromReturnedValue(), functionObjectForCall(), i, Q_UNLIKELY, QJSValue, qWarning, and QList< T >::size().

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◆ callWithInstance()

QJSValue QJSManagedValue::callWithInstance	(	const QJSValue &	instance,
		const QJSValueList &	arguments = {} ) const

If this QJSManagedValue represents a JavaScript FunctionObject, calls it on instance with the given arguments, and returns the result.

Otherwise returns a JavaScript undefined value.

The arguments and the instance have to be either primitive values or belong to the same QJSEngine as this QJSManagedValue. Otherwise the call is not carried out and a JavaScript undefined value is returned.

Definition at line 984 of file qjsmanagedvalue.cpp.

References arg, arguments, QJSValuePrivate::checkEngine(), QJSValuePrivate::convertToReturnedValue(), engine(), QJSValuePrivate::fromReturnedValue(), functionObjectForCall(), i, Q_UNLIKELY, QJSValue, qWarning, and QList< T >::size().

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◆ deleteProperty() [1/2]

bool QJSManagedValue::deleteProperty ( const QString & name )

Deletes the property name from this QJSManagedValue.

Returns true if the deletion succeeded, or false otherwise.

Definition at line 799 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QV4::IdentifierTable::asPropertyKey(), QV4::Scope::engine, and QV4::EngineBase::identifierTable.

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◆ deleteProperty() [2/2]

bool QJSManagedValue::deleteProperty ( quint32 arrayIndex )

Deletes the value stored at arrayIndex from this QJSManagedValue.

Returns true if the deletion succeeded, or false otherwise.

Definition at line 917 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), and QV4::PropertyKey::fromArrayIndex().

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◆ engine()

QJSEngine * QJSManagedValue::engine ( ) const

Returns the QJSEngine this QJSManagedValue belongs to.

Mind that the engine is always valid, unless the QJSManagedValue is default-constructed or moved from. In the latter case a nullptr is returned.

Definition at line 270 of file qjsmanagedvalue.cpp.

References QV4::PersistentValueStorage::getEngine().

Referenced by QJSManagedValue(), QJSManagedValue(), QJSManagedValue(), QJSManagedValue(), call(), callAsConstructor(), callWithInstance(), QJSValuePrivate::encode(), and jsMetaInstantiate().

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◆ equals()

bool QJSManagedValue::equals ( const QJSManagedValue & other ) const

Invokes the JavaScript '==' operator on this QJSManagedValue and other, and returns the result.

See also: strictlyEquals

Definition at line 239 of file qjsmanagedvalue.cpp.

References QV4::Runtime::CompareEqual::call(), QV4::StaticValue::isNullOrUndefined(), and other().

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◆ hasOwnProperty() [1/2]

bool QJSManagedValue::hasOwnProperty ( const QString & name ) const

Returns true if this QJSManagedValue has a property name, otherwise returns false.

The properties of the prototype chain are not considered.

Definition at line 721 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QV4::IdentifierTable::asPropertyKey(), QV4::Attr_Invalid, QV4::Scope::engine, QV4::EngineBase::identifierTable, QV4::StaticValue::isNullOrUndefined(), QV4::Value::isString(), and QStringLiteral.

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◆ hasOwnProperty() [2/2]

bool QJSManagedValue::hasOwnProperty ( quint32 arrayIndex ) const

Returns true if this QJSManagedValue has an array index arrayIndex, otherwise returns false.

The properties of the prototype chain are not considered.

Definition at line 843 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QV4::Attr_Invalid, QV4::PropertyKey::fromArrayIndex(), and QV4::StaticValue::isNullOrUndefined().

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◆ hasProperty() [1/2]

bool QJSManagedValue::hasProperty ( const QString & name ) const

Returns true if this QJSManagedValue has a property name, otherwise returns false.

The properties of the prototype chain are considered.

Definition at line 700 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QV4::IdentifierTable::asPropertyKey(), QV4::Scope::engine, hasProperty(), QV4::EngineBase::identifierTable, QV4::StaticValue::isNullOrUndefined(), QV4::Value::isString(), prototype(), and QStringLiteral.

Referenced by hasProperty(), and hasProperty().

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◆ hasProperty() [2/2]

bool QJSManagedValue::hasProperty ( quint32 arrayIndex ) const

Returns true if this QJSManagedValue has an array index arrayIndex, otherwise returns false.

The properties of the prototype chain are considered.

Definition at line 818 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), hasProperty(), QV4::StaticValue::isNullOrUndefined(), and prototype().

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◆ isArray()

bool QJSManagedValue::isArray ( ) const

Returns true if this value represents a JavaScript Array object, or false otherwise.

Definition at line 445 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isBoolean()

QJSManagedValue::isBoolean ( ) const

inline

Returns true if the type of this QJSManagedValue is boolean, or false otherwise.

Definition at line 55 of file qjsmanagedvalue.h.

◆ isDate()

bool QJSManagedValue::isDate ( ) const

Returns true if this value represents a JavaScript Date object, or false otherwise.

Definition at line 490 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isError()

bool QJSManagedValue::isError ( ) const

Returns true if this value represents a JavaScript Error object, or false otherwise.

Definition at line 499 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isFunction()

QJSManagedValue::isFunction ( ) const

inline

Returns true if the type of this QJSManagedValue is function, false otherwise.

Definition at line 60 of file qjsmanagedvalue.h.

◆ isInteger()

bool QJSManagedValue::isInteger ( ) const

Returns true if this QJSManagedValue holds an integer value, or false otherwise.

The storage format of a number does not affect the result of any operations performed on it, but if an integer is stored, many operations are faster.

Definition at line 427 of file qjsmanagedvalue.cpp.

References QV4::StaticValue::isInteger().

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◆ isJsMetaType()

bool QJSManagedValue::isJsMetaType ( ) const

Returns true if this value represents a JavaScript meta type, or false otherwise.

Definition at line 510 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isNull()

bool QJSManagedValue::isNull ( ) const

Returns true if this QJSManagedValue holds the JavaScript null value, or false otherwise.

Definition at line 416 of file qjsmanagedvalue.cpp.

References QV4::StaticValue::isNull().

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◆ isNumber()

QJSManagedValue::isNumber ( ) const

inline

Returns true if the type of this QJSManagedValue is number, or false otherwise.

Definition at line 56 of file qjsmanagedvalue.h.

◆ isObject()

QJSManagedValue::isObject ( ) const

inline

Returns true if the type of this QJSManagedValue is object, or false otherwise.

Definition at line 58 of file qjsmanagedvalue.h.

◆ isQMetaObject()

bool QJSManagedValue::isQMetaObject ( ) const

Returns true if this value represents a QMetaObject pointer managed on the JavaScript heap, or false otherwise.

Definition at line 481 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isQObject()

bool QJSManagedValue::isQObject ( ) const

Returns true if this value represents a QObject pointer managed on the JavaScript heap, or false otherwise.

Definition at line 472 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isRegularExpression()

bool QJSManagedValue::isRegularExpression ( ) const

Returns true if this value represents a JavaScript regular expression object, or false otherwise.

Definition at line 436 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isString()

QJSManagedValue::isString ( ) const

inline

Returns true if the type of this QJSManagedValue is string, or false otherwise.

Definition at line 57 of file qjsmanagedvalue.h.

◆ isSymbol()

QJSManagedValue::isSymbol ( ) const

inline

Returns true if the type of this QJSManagedValue is symbol, or false otherwise.

Definition at line 59 of file qjsmanagedvalue.h.

◆ isUndefined()

QJSManagedValue::isUndefined ( ) const

inline

Returns true if the type of this QJSManagedValue is undefined, or false otherwise.

Definition at line 54 of file qjsmanagedvalue.h.

References Undefined.

◆ isUrl()

bool QJSManagedValue::isUrl ( ) const

Returns true if this value represents a JavaScript Url object, or false otherwise.

Definition at line 454 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ isVariant()

bool QJSManagedValue::isVariant ( ) const

Returns true if this value represents a QVariant managed on the JavaScript heap, or false otherwise.

Definition at line 463 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ jsMetaInstantiate()

QJSManagedValue QJSManagedValue::jsMetaInstantiate ( const QJSValueList & values = {} ) const

If this value is a JavaScript meta type, instantiates it using the values, and returns the result. Otherwise returns undefined.

The values are expected in the same order as the keys in the return value of members(), and that is the order in which properties were added to the object this meta type originally belongs to.

See also: members(), metaType(), isMetaType().

Definition at line 1113 of file qjsmanagedvalue.cpp.

References QJSManagedValue(), arg, QV4::Value::as(), QJSValuePrivate::checkEngine(), QJSValuePrivate::convertToReturnedValue(), engine(), i, o, Q_UNLIKELY, qMin(), and qWarning.

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◆ jsMetaMembers()

QStringList QJSManagedValue::jsMetaMembers ( ) const

If this value is a JavaScript meta type, retrieves the names of its members The ordering of the names corresponds to the ordering of the values to be passed to instantiate().

If the value is not a meta type, an empty list is returned.

See also: isMetaType(), metaType(), instantiate()

Definition at line 1080 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), and i.

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◆ jsMetaType()

QJSManagedValue QJSManagedValue::jsMetaType ( ) const

Retrieves the JavaScript meta type of this value. The JavaScript meta type represents the layout of members in an object. Instantiating a meta type is faster than re-constructing the same object using a sequence of setProperty() calls on a new object.

See also: members(), instantiate()

Definition at line 1057 of file qjsmanagedvalue.cpp.

References QJSManagedValue(), QV4::Value::as(), and v4Engine().

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◆ operator=()

QJSManagedValue & QJSManagedValue::operator= ( QJSManagedValue && other )

Move-assigns a QJSManagedValue from other.

This leaves other in the default-constructed state where it represents undefined and does not belong to any engine.

Note: This frees the memory slot this QJSManagedValue holds on the JavaScript heap. You must not move-assign a QJSManagedValue on a different thread than the one where the QJSEngine it belongs to lives.

Definition at line 223 of file qjsmanagedvalue.cpp.

References QV4::PersistentValueStorage::free(), other(), and qSwap().

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◆ property() [1/2]

QJSValue QJSManagedValue::property ( const QString & name ) const

Returns the property name of this QJSManagedValue.

The prototype chain is searched if the property is not found on the actual object.

Definition at line 742 of file qjsmanagedvalue.cpp.

References arg, QV4::Value::as(), QV4::IdentifierTable::asPropertyKey(), QV4::Scope::engine, QJSValuePrivate::fromReturnedValue(), QV4::EngineBase::identifierTable, QV4::StaticValue::isNullOrUndefined(), property(), prototype(), QJSValue, QStringLiteral, QV4::ExecutionEngine::throwTypeError(), and v4Engine().

Referenced by property(), and property().

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◆ property() [2/2]

QJSValue QJSManagedValue::property ( quint32 arrayIndex ) const

Returns the property stored at arrayIndex of this QJSManagedValue.

The prototype chain is searched if the property is not found on the actual object.

Definition at line 869 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QJSValuePrivate::fromReturnedValue(), QV4::StaticValue::isNullOrUndefined(), property(), prototype(), QJSValue, and QString::sliced().

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◆ prototype()

QJSManagedValue QJSManagedValue::prototype ( ) const

Returns the prototype for this QJSManagedValue.

This works on any value. You can, for example retrieve the JavaScript boolean prototype from a boolean value.

Definition at line 284 of file qjsmanagedvalue.cpp.

References QJSManagedValue(), QV4::Value::as(), QV4::ExecutionEngine::booleanPrototype(), QV4::StaticValue::isBoolean(), QV4::StaticValue::isNumber(), managed(), QV4::Encode::null(), QV4::ExecutionEngine::numberPrototype(), prototype(), and v4Engine().

Referenced by hasProperty(), hasProperty(), property(), property(), prototype(), and setPrototype().

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◆ setProperty() [1/2]

void QJSManagedValue::setProperty	(	const QString &	name,
		const QJSValue &	value )

Sets the property name to value on this QJSManagedValue.

This can only be done on JavaScript values of type object. Furhermore, value has to be either a primitive or belong to the same engine as this value.

Definition at line 772 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QV4::IdentifierTable::asPropertyKey(), QJSValuePrivate::convertToReturnedValue(), QJSValuePrivate::engine(), QV4::Scope::engine, QV4::EngineBase::identifierTable, QV4::StaticValue::isNullOrUndefined(), Q_UNLIKELY, QStringLiteral, qWarning, and v4Engine().

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◆ setProperty() [2/2]

void QJSManagedValue::setProperty	(	quint32	arrayIndex,
		const QJSValue &	value )

Stores the value at arrayIndex in this QJSManagedValue.

This can only be done on JavaScript values of type object, and it's not recommended if the value is not an array. Furhermore, value has to be either a primitive or belong to the same engine as this value.

Definition at line 897 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QJSValuePrivate::convertToReturnedValue(), QJSValuePrivate::engine(), Q_UNLIKELY, and qWarning.

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◆ setPrototype()

void QJSManagedValue::setPrototype ( const QJSManagedValue & prototype )

Sets the prototype of this QJSManagedValue to prototype.

A precondition is that prototype belongs to the same QJSEngine as this QJSManagedValue and is an object (including null). Furthermore, this QJSManagedValue has to be an object (excluding null), too, and you cannot create prototype cycles.

Definition at line 314 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), Object, prototype(), Q_UNLIKELY, qWarning, type(), and v4Engine().

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◆ strictlyEquals()

bool QJSManagedValue::strictlyEquals ( const QJSManagedValue & other ) const

Invokes the JavaScript '===' operator on this QJSManagedValue and other, and returns the result.

See also: equals

Definition at line 255 of file qjsmanagedvalue.cpp.

References QV4::StaticValue::isUndefined(), other(), and QV4::RuntimeHelpers::strictEqual().

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◆ toBoolean()

bool QJSManagedValue::toBoolean ( ) const

Converts the manged value to a boolean.

If the managed value holds a boolean, that one is returned. Otherwise a boolean coercion by JavaScript rules is performed.

Definition at line 550 of file qjsmanagedvalue.cpp.

References QV4::Value::toBoolean().

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◆ toDateTime()

QDateTime QJSManagedValue::toDateTime ( ) const

If this QJSManagedValue holds a JavaScript Date object, returns an equivalent QDateTime.

Otherwise returns an invalid one.

Definition at line 689 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ toInteger()

int QJSManagedValue::toInteger ( ) const

Converts the manged value to an integer.

This first converts the value to a number by the rules of toNumber(), and then clamps it into the integer range by the rules given for coercing the arguments to JavaScript bit shift operators into 32bit integers.

Internally, the value may already be stored as an integer, in which case a fast path is taken.

Note: Conversion of a managed value to a number can throw an exception. In particular, symbols cannot be coerced into numbers, or a custom valueOf() method may throw. In this case the result is 0 and the engine carries an error after the conversion.; The JavaScript rules for coercing numbers into 32bit integers are unintuitive.

Definition at line 572 of file qjsmanagedvalue.cpp.

References QV4::Value::toInt32().

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◆ toJSValue()

QJSValue QJSManagedValue::toJSValue ( ) const

Copies this QJSManagedValue into a new QJSValue.

This is less efficient than move-constructing a QJSValue from a QJSManagedValue, but retains the QJSManagedValue.

Definition at line 611 of file qjsmanagedvalue.cpp.

References QV4::StaticValue::asReturnedValue(), QJSValuePrivate::fromReturnedValue(), and QJSValue.

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◆ toNumber()

double QJSManagedValue::toNumber ( ) const

Converts the manged value to a number.

If the managed value holds a number, that one is returned. Otherwise a number coercion by JavaScript rules is performed.

Note: Conversion of a managed value to a number can throw an exception. In particular, symbols cannot be coerced into numbers, or a custom valueOf() method may throw. In this case the result is 0 and the engine carries an error after the conversion.

Definition at line 540 of file qjsmanagedvalue.cpp.

References QV4::Value::toNumber().

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◆ toPrimitive()

QJSPrimitiveValue QJSManagedValue::toPrimitive ( ) const

Converts the manged value to a QJSPrimitiveValue.

If the managed value holds a type supported by QJSPrimitiveValue, the value is copied. Otherwise the value is converted to a string, and the string is stored in QJSPrimitiveValue.

Note: Conversion of a managed value to a string can throw an exception. In particular, symbols cannot be coerced into strings, or a custom toString() method may throw. In this case the result is the undefined value and the engine carries an error after the conversion.

Definition at line 588 of file qjsmanagedvalue.cpp.

References QV4::StaticValue::booleanValue(), QV4::StaticValue::doubleValue(), QV4::StaticValue::integerValue(), QV4::StaticValue::isBoolean(), QV4::StaticValue::isInteger(), QV4::StaticValue::isNull(), QV4::StaticValue::isNumber(), QV4::StaticValue::isUndefined(), ok, and QV4::Value::toQString().

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◆ toQMetaObject()

const QMetaObject * QJSManagedValue::toQMetaObject ( ) const

If this QJSManagedValue holds a QMetaObject pointer, returns it.

Otherwise returns nullptr.

Definition at line 678 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ toQObject()

QObject * QJSManagedValue::toQObject ( ) const

If this QJSManagedValue holds a QObject pointer, returns it.

Otherwise returns nullptr.

Definition at line 667 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), and o.

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◆ toRegularExpression()

QRegularExpression QJSManagedValue::toRegularExpression ( ) const

If this QJSManagedValue holds a JavaScript regular expression object, returns an equivalent QRegularExpression.

Otherwise returns an invalid one.

Definition at line 645 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ toString()

QString QJSManagedValue::toString ( ) const

Converts the manged value to a string.

If the managed value holds a string, that one is returned. Otherwise a string coercion by JavaScript rules is performed.

Note: Conversion of a managed value to a string can throw an exception. In particular, symbols cannot be coerced into strings, or a custom toString() method may throw. In this case the result is an empty string and the engine carries an error after the conversion.

Definition at line 525 of file qjsmanagedvalue.cpp.

References QStringLiteral, and QV4::Value::toQString().

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◆ toUrl()

QUrl QJSManagedValue::toUrl ( ) const

If this QJSManagedValue holds a JavaScript Url object, returns an equivalent QUrl.

Otherwise returns an invalid one.

Definition at line 656 of file qjsmanagedvalue.cpp.

References QV4::Value::as().

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◆ toVariant()

QVariant QJSManagedValue::toVariant ( ) const

Copies this QJSManagedValue into a new QVariant.

This also creates a useful QVariant if QJSManagedValue::isVariant() returns false. QVariant can hold all types supported by QJSManagedValue.

Definition at line 621 of file qjsmanagedvalue.cpp.

References QV4::Value::as(), QV4::StaticValue::booleanValue(), QV4::StaticValue::doubleValue(), QV4::StaticValue::integerValue(), QV4::StaticValue::isBoolean(), QV4::StaticValue::isInteger(), QV4::StaticValue::isNull(), QV4::StaticValue::isNumber(), QV4::Value::isString(), QV4::StaticValue::isUndefined(), QV4::Value::toQString(), and QV4::ExecutionEngine::toVariant().

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◆ type()

QJSManagedValue::Type QJSManagedValue::type ( ) const

Returns the JavaScript type of this QJSManagedValue.

Definition at line 346 of file qjsmanagedvalue.cpp.

References Boolean, Function, QV4::StaticValue::isBoolean(), QV4::Value::isFunctionObject(), QV4::StaticValue::isNumber(), QV4::Value::isString(), QV4::Value::isSymbol(), QV4::StaticValue::isUndefined(), Number, Object, String, Symbol, and Undefined.

Referenced by setPrototype().

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Friends And Related Symbol Documentation

◆ QJSEngine

friend class QJSEngine

friend

Definition at line 122 of file qjsmanagedvalue.h.

◆ QJSValue

friend class QJSValue

friend

Definition at line 121 of file qjsmanagedvalue.h.

Referenced by call(), callAsConstructor(), callWithInstance(), property(), property(), and toJSValue().

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

qtdeclarative/src/qml/jsapi/qjsmanagedvalue.h (0dc4fd240a2897c5c443a0ef6d84c416843e4938)
qtdeclarative/src/qml/jsapi/qjsmanagedvalue.cpp (59c5038af49b82a8ee9c93455cdf093fa097aec8)

Public Types

Public Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ Type

Constructor & Destructor Documentation

◆ QJSManagedValue() [1/6]

◆ QJSManagedValue() [2/6]

◆ QJSManagedValue() [3/6]

◆ QJSManagedValue() [4/6]

◆ QJSManagedValue() [5/6]

◆ ~QJSManagedValue()

◆ QJSManagedValue() [6/6]

Member Function Documentation

◆ call()

◆ callAsConstructor()

◆ callWithInstance()

◆ deleteProperty() [1/2]

◆ deleteProperty() [2/2]

◆ engine()

◆ equals()

◆ hasOwnProperty() [1/2]

◆ hasOwnProperty() [2/2]

◆ hasProperty() [1/2]

◆ hasProperty() [2/2]

◆ isArray()

◆ isBoolean()

◆ isDate()

◆ isError()

◆ isFunction()

◆ isInteger()

◆ isJsMetaType()

◆ isNull()

◆ isNumber()

◆ isObject()

◆ isQMetaObject()

◆ isQObject()

◆ isRegularExpression()

◆ isString()

◆ isSymbol()

◆ isUndefined()

◆ isUrl()

◆ isVariant()

◆ jsMetaInstantiate()

◆ jsMetaMembers()

◆ jsMetaType()

◆ operator=()

◆ property() [1/2]

◆ property() [2/2]

◆ prototype()

◆ setProperty() [1/2]

◆ setProperty() [2/2]

◆ setPrototype()

◆ strictlyEquals()

◆ toBoolean()

◆ toDateTime()

◆ toInteger()

◆ toJSValue()

◆ toNumber()

◆ toPrimitive()

◆ toQMetaObject()

◆ toQObject()

◆ toRegularExpression()

◆ toString()

◆ toUrl()

◆ toVariant()

◆ type()

Friends And Related Symbol Documentation

◆ QJSEngine

◆ QJSValue