QJSValueIterator Class Reference

The QJSValueIterator class provides a Java-style iterator for QJSValue. More...

#include <qjsvalueiterator.h>

Collaboration diagram for QJSValueIterator:

Public Member Functions
	QJSValueIterator (const QJSValue &value)
	Constructs an iterator for traversing object.
	~QJSValueIterator ()
	Destroys the iterator.
bool	hasNext () const
	Returns true if there is at least one item ahead of the iterator (i.e.
bool	next ()
	Advances the iterator by one position.
QString	name () const
	Returns the name of the last property that was jumped over using next().
QJSValue	value () const
	Returns the value of the last property that was jumped over using next().
QJSValueIterator &	operator= (QJSValue &value)
	Makes the iterator operate on object.

Detailed Description

The QJSValueIterator class provides a Java-style iterator for QJSValue.

\inmodule QtQml

The QJSValueIterator constructor takes a QJSValue as argument. After construction, the iterator is located at the very beginning of the sequence of properties. Here's how to iterate over all the properties of a QJSValue:

QJSValue object;
...
QJSValueIterator it(object);
while (it.hasNext()) {
    it.next();
    qDebug() << it.name() << ": " << it.value().toString();
}

The next() advances the iterator. The name() and value() functions return the name and value of the last item that was jumped over.

Note that QJSValueIterator only iterates over the QJSValue's own properties; i.e. it does not follow the prototype chain. You can use a loop like this to follow the prototype chain:

QJSValue obj = ...; // the object to iterate over
while (obj.isObject()) {
    QJSValueIterator it(obj);
    while (it.hasNext()) {
        it.next();
        qDebug() << it.name();
    }
    obj = obj.prototype();
}

See also

QJSValue::property()

Definition at line 17 of file qjsvalueiterator.h.

Constructor & Destructor Documentation

QJSValueIterator()

QJSValueIterator::QJSValueIterator

(

const QJSValue &

object

)

Constructs an iterator for traversing object.

The iterator is set to be at the front of the sequence of properties (before the first property).

Definition at line 93 of file qjsvalueiterator.cpp.

~QJSValueIterator()

QJSValueIterator::~QJSValueIterator

(

)

Destroys the iterator.

Definition at line 101 of file qjsvalueiterator.cpp.

Member Function Documentation

hasNext()

bool QJSValueIterator::hasNext

(

)

const

Returns true if there is at least one item ahead of the iterator (i.e.

the iterator is not at the back of the property sequence); otherwise returns false.

See also

next()

Definition at line 112 of file qjsvalueiterator.cpp.

References QV4::PropertyKey::fromId(), QJSValueIteratorPrivate::isValid(), QV4::PropertyKey::isValid(), QJSValueIteratorPrivate::nextKey, and QV4::PersistentValue::value().

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name()

QString QJSValueIterator::name

(

)

const

Returns the name of the last property that was jumped over using next().

See also

value()

Definition at line 141 of file qjsvalueiterator.cpp.

References QJSValueIteratorPrivate::currentKey, QJSValueIteratorPrivate::engine, QV4::PropertyKey::fromId(), QJSValueIteratorPrivate::isValid(), Q_ASSERT, and QV4::PersistentValue::value().

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next()

bool QJSValueIterator::next

(

)

Advances the iterator by one position.

Returns true if there was at least one item ahead of the iterator (i.e. the iterator was not already at the back of the property sequence); otherwise returns false.

See also

hasNext(), name()

Definition at line 127 of file qjsvalueiterator.cpp.

References QJSValueIteratorPrivate::currentKey, QV4::PropertyKey::fromId(), QJSValueIteratorPrivate::isValid(), QV4::PropertyKey::isValid(), QJSValueIteratorPrivate::next(), and QV4::PersistentValue::value().

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operator=()

QJSValueIterator & QJSValueIterator::operator=

(

QJSValue &

object

)

Makes the iterator operate on object.

The iterator is set to be at the front of the sequence of properties (before the first property).

Definition at line 185 of file qjsvalueiterator.cpp.

References QJSValueIteratorPrivate::init().

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value()

QJSValue QJSValueIterator::value

(

)

const

Returns the value of the last property that was jumped over using next().

See also

name()

Definition at line 160 of file qjsvalueiterator.cpp.

References QV4::PersistentValue::asManaged(), QV4::ExecutionEngine::catchException(), QJSValueIteratorPrivate::currentKey, QJSValueIteratorPrivate::engine, QV4::Scope::engine, QV4::PropertyKey::fromId(), QJSValuePrivate::fromReturnedValue(), QV4::Scope::hasException(), QJSValueIteratorPrivate::isValid(), QJSValueIteratorPrivate::object, and QV4::PersistentValue::value().

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

• qtdeclarative/src/qml/jsapi/qjsvalueiterator.h
• qtdeclarative/src/qml/jsapi/qjsvalueiterator.cpp