QQmlNetworkAccessManagerFactory Class

The QQmlNetworkAccessManagerFactory class creates QNetworkAccessManager instances for a QML engine. More...

Header: #include <QQmlNetworkAccessManagerFactory>
CMake: find_package(Qt6 REQUIRED COMPONENTS Qml)
target_link_libraries(mytarget PRIVATE Qt6::Qml)
qmake: QT += qml

Public Functions

virtual ~QQmlNetworkAccessManagerFactory()
virtual QNetworkAccessManager *create(QObject *parent) = 0

Detailed Description

A QML engine uses QNetworkAccessManager for all network access. By implementing a factory, it is possible to provide the QML engine with custom QNetworkAccessManager instances with specialized caching, proxy and cookies support.

To implement a factory, subclass QQmlNetworkAccessManagerFactory and implement the virtual create() method, then assign it to the relevant QML engine using QQmlEngine::setNetworkAccessManagerFactory(). For instance, the QNetworkAccessManager objects created by the following snippet will cache requests.

class CachingNetworkAccessManagerFactory : public QQmlNetworkAccessManagerFactory

    inline QNetworkAccessManager *create(QObject *parent) override
        QNetworkAccessManager *networkAccessManager = new QNetworkAccessManager(parent);
        QNetworkDiskCache *diskCache = new QNetworkDiskCache(parent);

        return networkAccessManager;

The factory can then be passed to the QML engine so it can instantiate the QNetworkAccessManager with the custom behavior.

CachingNetworkAccessManagerFactory networkManagerFactory;

Note the QML engine may create QNetworkAccessManager instances from multiple threads. Because of this, the implementation of the create() method must be reentrant. In addition, the developer should be careful if the signals of the object to be returned from create() are connected to the slots of an object that may be created in a different thread:

For more information about signals and threads, see Threads and QObjects and Signals and Slots Across Threads.

See also QNetworkDiskCache.

Member Function Documentation

[virtual noexcept] QQmlNetworkAccessManagerFactory::~QQmlNetworkAccessManagerFactory()

Destroys the factory. The default implementation does nothing.

[pure virtual] QNetworkAccessManager *QQmlNetworkAccessManagerFactory::create(QObject *parent)

Creates and returns a network access manager with the specified parent. This method must return a new QNetworkAccessManager instance each time it is called.

Note: this method may be called by multiple threads, so ensure the implementation of this method is reentrant.

© 2024 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.