QJSManagedValue Class

Member Function Documentation

QJSManagedValue::QJSManagedValue()

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.

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.

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

Creates a QJSManagedValue from value using the heap of engine.

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

Creates a QJSManagedValue from variant using the heap of engine.

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

Creates a QJSManagedValue from string using the heap of engine.

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.

QJSManagedValue::~QJSManagedValue()

Destroys the QJSManagedValue.

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.

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.

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.

bool QJSManagedValue::deleteProperty(const QString &name)

Deletes the property name from this QJSManagedValue. Returns true if the deletion succeeded, or false otherwise.

bool QJSManagedValue::deleteProperty(quint32 arrayIndex)

Deletes the value stored at arrayIndex from this QJSManagedValue. Returns true if the deletion succeeded, or false otherwise.

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.

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

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

See also strictlyEquals.

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.

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.

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.

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.

bool QJSManagedValue::isArray() const

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

bool QJSManagedValue::isBoolean() const

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

bool QJSManagedValue::isDate() const

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

bool QJSManagedValue::isError() const

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

bool QJSManagedValue::isFunction() const

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

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.

bool QJSManagedValue::isNull() const

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

bool QJSManagedValue::isNumber() const

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

bool QJSManagedValue::isObject() const

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

bool QJSManagedValue::isQMetaObject() const

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

bool QJSManagedValue::isQObject() const

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

bool QJSManagedValue::isRegularExpression() const

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

bool QJSManagedValue::isString() const

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

bool QJSManagedValue::isSymbol() const

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

bool QJSManagedValue::isUndefined() const

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

bool QJSManagedValue::isUrl() const

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

bool QJSManagedValue::isVariant() const

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

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.

See also setProperty().

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.

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.

See also setPrototype().

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.

See also property().

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.

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.

See also prototype().

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

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

See also equals.

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.

QDateTime QJSManagedValue::toDateTime() const

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

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.

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.

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.

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.

const QMetaObject *QJSManagedValue::toQMetaObject() const

If this QJSManagedValue holds a QMetaObject pointer, returns it. Otherwise returns nullptr.

QObject *QJSManagedValue::toQObject() const

If this QJSManagedValue holds a QObject pointer, returns it. Otherwise returns nullptr.

QRegularExpression QJSManagedValue::toRegularExpression() const

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

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.

QUrl QJSManagedValue::toUrl() const

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

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.

QJSManagedValue::Type QJSManagedValue::type() const

Returns the JavaScript type of this QJSManagedValue.

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.