Hi Brett,
Many thanks for the Test file link. That is really an interesting source
of information. I looked in examples but not in tests.
My lone problem was I didn't know the optional
Q_RETURN_ARG(QRemoteObjectPendingCall, call) required when wanted return
value, and i didn't find information about a return value in the
metamethod (RO seems to remove the ReturnValueType)
At my knowledge, this information is missing in documentation.
I have now everything working in C++ but how is exposed this
QRemoteObjectPendingCall in QML ? with a PendingReply ?
Is there an example of that also (calling a slot with pending value on a
dynamic replica from qml) ?
Cordially.
Daes
Le 08/08/2019 à 21:37, Stottlemyer, Brett (B.S.) a écrit :
Hi,
The constructor is private because you aren’t intended to create the
dynamic replica directly, you must get it from a node. The object
won’t be valid until it receives an initial state from a source in
another node, so the nodes must be connected together.
See:
https://code.woboq.org/qt5/qtremoteobjects/src/remoteobjects/qremoteobjectnode.h.html#_ZN17QRemoteObjectNode14acquireDynamicERK7QString
Once the node is initialized, you can use Qt’s introspection methods
to understand the properties, signals and slots available.
A usage example can be found in the tests, here:
https://code.woboq.org/qt5/qtremoteobjects/tests/auto/integration/tst_integration.cpp.html#_ZN15tst_Integration22slotTestDynamicReplicaEv
Using dynamica replicas is available, but is generally much more
difficult than using repc. So repc is certainly recommended for most
use-cases.
Regards,
Brett
*From:*Interest <interest-boun...@qt-project.org> *On Behalf Of *Daesdemon
*Sent:* Thursday, August 8, 2019 3:03 PM
*To:* interest@qt-project.org
*Subject:* [Interest] QRemoteObjectDynamicReplica: How get a slot
return value?
Hi Qt people,
I have been advised to post this kind of question on the maillist
instead of forum. If it is the wrong place, please, forgive me.
After digging in REPC generated code and RO sources, i found there is
some "kind of magic" in the REPC code:
- The call of returning value slot in REPC generated object use
the protected |sendWithReply| function of QRemoteObjectReplica (async
call, returning a kind of future object: |QRemoteObjectPendingReply<T>
with T of the ReturnType of the slot)|
The problem is that the QRemoteObjectDynamicReplica have no public
constructor, so no way to use this function even by derivation.
The slot signature in the dynamic replica metaobject also has no
functor parameter to get the return value async. In fact the signature
even loose the ReturnValue Type.
So how could we get a slot return value from a dynamic Replica ?
If there is no way (without re-coding a large part) to do this, I find
this lack of feature really troublesome in my case, where the main
spec is to have no use of REPC.
A subsidiary question could be : Why is the
|QRemoteObjectDynamicReplica(QRemoteObjectNode *node, const QString
&name)| constructor private ?
If public, it would allow to overload acquireDynamic in
QRemoteObjectNode and extend QRemoteObjectDynamicReplica by
derivation, for, in this case, expose internally the sendAndReply
function.
However the lack of the return value type would still be a problem.
I understand principle of encapsulation but i am in dead-end there.
If someone had a clue, i'll take it gratefully.
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