QWebChannel Class

Exposes QObjects to remote HTML clients. More...

Header: #include <QWebChannel>
qmake: QT += webchannel
Since: Qt 5.4
Inherits: QObject

This class was introduced in Qt 5.4.

Properties

Public Functions

bool blockUpdates() const
void setBlockUpdates(bool block)

Signals

void blockUpdatesChanged(bool block)

Detailed Description

The QWebChannel fills the gap between C++ applications and HTML/JavaScript applications. By publishing a QObject derived object to a QWebChannel and using the qwebchannel.js on the HTML side, one can transparently access properties and public slots and methods of the QObject. No manual message passing and serialization of data is required, property updates and signal emission on the C++ side get automatically transmitted to the potentially remotely running HTML clients. On the client side, a JavaScript object will be created for any published C++ QObject. It mirrors the C++ object's API and thus is intuitively useable.

The C++ QWebChannel API makes it possible to talk to any HTML client, which could run on a local or even remote machine. The only limitation is that the HTML client supports the JavaScript features used by qwebchannel.js. As such, one can interact with basically any modern HTML browser or standalone JavaScript runtime, such as node.js.

There also exists a declarative WebChannel API.

See also Qt WebChannel Standalone Example and JavaScript API.

Property Documentation

blockUpdates : bool

When set to true, updates are blocked and remote clients will not be notified about property changes.

The changes are recorded and sent to the clients once updates become unblocked again by setting this property to false. By default, updates are not blocked.

Access functions:

bool blockUpdates() const
void setBlockUpdates(bool block)

Notifier signal:

void blockUpdatesChanged(bool block)