When a slot is called in an object due to a signal delivery or due to a remote method call, it is sometimes necessary to know the context in which that happened. In particular, if the slot determines that it wants to send the reply at a later opportunity or if it wants to reply with an error, the context is needed.
QDBusContext class is an alternative to accessing the context that doesn’t involve modifying the code generated by the Qt D-Bus XML compiler (qdbusxml2cpp) .
class MyObject(QObject, QDBusContext = protected() Q_OBJECT conn = QDBusConnection() msg = QDBusMessage() #... slots: = protected() def process(): slots: = public() def methodWithError(): methodWithDelayedReply = QString() def methodWithError(self): sendErrorReply(QDBusError.NotSupported, "The method call 'methodWithError()' is not supported") def methodWithDelayedReply(self): conn = connection() msg = message() setDelayedReply(True) QMetaObject.invokeMethod(self, "process", Qt.QueuedConnection) def QString():
The example illustrates the two typical uses, that of sending error replies and that of delayed replies.
Note: do not subclass
QDBusAbstractAdaptor at the same time.
QDBusContext should appear in the real object, not the adaptor. If it’s necessary from the adaptor code to determine the context, use a public inheritance and access the functions via
- class PySide6.QtDBus.QDBusContext¶
Constructs an empty
- Return type
true if we are processing a D-Bus call. If this function returns
true, the rest of the functions in this class are available.
Accessing those functions when this function returns
false is undefined and may lead to crashes.
Returns the connection from which this call was received.
- Return type
true if this call will have a delayed reply.
Returns the message that generated this call.
- PySide6.QtDBus.QDBusContext.sendErrorReply(name[, msg=""])
name – str
msg – str
enable – bool
Sets whether this call will have a delayed reply or not.
enable is false, Qt D-Bus will automatically generate a reply back to the caller, if needed, as soon as the called slot returns.
enable is true, Qt D-Bus will not generate automatic replies. It will also ignore the return value from the slot and any output parameters. Instead, the called object is responsible for storing the incoming message and send a reply or error at a later time.
Failing to send a reply will result in an automatic timeout error being generated by D-Bus.
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