[Development] QTCS2019 Notes from QtQml session

Olivier Goffart olivier at woboq.com
Tue Nov 26 12:35:26 CET 2019

On 25.11.19 16:36, André Somers wrote:
> On 25-11-19 15:53, Ulf Hermann wrote:
>>> Yeah, that's going to make using QML in actual applications a whole lot
>>> harder. For instance, sometimes access to some root node is needed even
>>> from deep leaf files. Removing that capability is quite a drastic measure.
>> Yes, but the problems with this construct are the same as with generic
>> context properties: Your QML component requires some context that it
>> doesn't declare. Therefore your code is not reusable and brittle wrt
>> addition of properties in other places.
>> Mind that all those dynamic lookups will still live on in QML 2, and we
>> will maintain QML 2 throughout Qt6. They just won't be valid in QML 3.
> "It will still work in QML 2" is not a great one if you want people to port 
> over to QML 3. And you will need to support something like this anyway.
> So far, the feeling I'm getting is that you're quite rigorously axing things 
> from QML 2 in QML 3 in order to clean up because it is "broken" in QML 2. But 
> without careful consideration what should replace it, that will just lead to 
> the same issues again or a less usable QML for real world applications.
> I'm a bit concerned.

Maybe the marketing isn't quite right.
Perhaps it shouldn't be named "QML 3"  but "QML strict"
QML3 tell peolpe
"This is the new version, you should port your code, the old version is going 
to be deprecated at some point"
While maybe true, I understand people's frustration. And since you will need to 
maintain both QML2 and QML3 at the same time, it might be better to rename it 
to something like "QML Strict" which convey the meaning:
"QML Strict is as subset of QML which is more maintainable and performs better"


More information about the Development mailing list