Hi,
(sorry in advance for the long post).

I was trying (and still working on it) to build a *QML-only* client for
Whatser, a social service for sharing interesting places (called spots) with
friends.
The API is JSON-based and there are usable clients on all the most popular
mobile platforms (missing Symbian, of course ;-)) and for the web (
www.whatser.com).

Here are some of the problems I ran into (from the least to the most
important one):
1) the XMLHttpRequest object does not support the DELETE method. This would
be trivial to fix if I could change the API but I can't and it is required
for certain operations (e.g. removing a spot from your own collection). I
could also fix that using some little C++ but it messed up my plans. (
QTBUG-17963 <http://bugreports.qt.nokia.com/browse/QTBUG-17963>)
2) I use .js files with WorkerScripts to perform the network calls. In those
files I used to Qt.include() other js files (essentially some global
objects). Everything works smoothly on OSX (where I develop) but I
discovered the hard way that it doesn't on Windows and on Symbian. Now I'm
in the process of changing the code so those objects get passed around as
parameters but the fact that it was working (and it is supposed to work) on
OSX means that I was using the same pattern in a lot of places that I now
have to change. Another time delay.
(QTBUG-17977<http://bugreports.qt.nokia.com/browse/QTBUG-17977>
)
3) I've recently found that on Symbian (at least on my device, a  low-end
5230) I get an error while receiving the JSON stream . Everything works fine
on OSX and Windows and it just fails on Symbian
(QTBUG-18097<http://bugreports.qt.nokia.com/browse/QTBUG-18097>
).
I still have no idea what's going wrong and how to work around it (basically
the entire app does not work if that does not work but I still hope it is
somehow my fault).

Now, none of the above-mentioned problem is in itself worth dropping QML
altogether, but to me it means that the platform is still not reliable for
production, also considering that my app does not use anything extremely
advanced, where I can expect more issues.
Keep in mind it's a beta version of the SDK so some frustration is expected
and acceptable for me. And Whatser in QML is just my pet project, not
something I plan to sell ;-)

But since it's uncertain when QML will be ready and available on Symbian for
distribution (afaik), I would stay away from it for production projects for
now. (and maybe stick with Qt in c++ mode).

cheers,
Mario

(if you're interested the project is hosted on projects.forum.nokia.com with
a couple of screenshots and a short video showing what should be working so
far).


On 15 March 2011 20:20, Bo Elmgreen <[email protected]> wrote:

> Hi,
>
> Mario, could you please elaborate a bit more on your negative experiences?
>
> We are considering using QML in a production mobile client, where the
> intention is to use it for a "thin" UI layer, so the real functionality is
> implemented in Qt C++, but is this a risky strategy? Is QML still only
> suitable for demos? ;-) So far we have made some UI prototypes, and even on
> old Windows Mobile handsets, they worked pretty ok...
>
> Thanks,
> Bo
>
>
> On Tue, Mar 15, 2011 at 3:15 PM, Mario Negro Ponzi <
> [email protected]> wrote:
>
>> Hi, my experience is negative.
>> I'm creating a relative simple app and I did discover some very serious
>> issues that are blocking me (or at least slowing me down a lot trying to
>> find workarounds).
>>
>> As said before also my impression is that QML is ready for animating the
>> UI, but it's way better to keep anything non trivial in C++. And there are
>> some bugs affecting the phone which don't show up in the desktop.
>>
>> I would keep an eye on
>>
>> http://bugreports.qt.nokia.com/secure/IssueNavigator.jspa?reset=true&jqlQuery=project+%3D+QTBUG+AND+resolution+%3D+Unresolved+AND+component+%3D+%22Declarative+%28QML%29%22+ORDER+BY+priority+DESC&mode=hide
>> to get a feeling of where QML is right now.
>>
>> And check also where qtmobility is in case you need it ;-)
>>
>> And no, afaik you can't publish to the OVI store QML apps, yet.
>>
>> Having said that, QML is a *fantastic* technology and I can't wait for it
>> to be ready. I was also quite impressed by the performance it can achieve on
>> the relatively low-end Nokia 5230.
>>
>>
>> cheers,
>> Mario
>>
>> On 15 March 2011 12:05, Adriano Gil <[email protected]> wrote:
>>
>>> What about Qt 4.7 for symbian^3?
>>> Is there an official .sis package or only the developer version?
>>>
>>> Can I submit a QML app to OVI Store right now?
>>>
>>> cheers
>>>
>>> Adriano
>>>
>>> 2011/3/1 Jason H <[email protected]>
>>>
>>>> In my limited experience, I would also agree. I've been running QML
>>>> animations
>>>> for weeks and no memory leaks, no slow-downs.
>>>>
>>>>
>>>>
>>>>
>>>> ----- Original Message ----
>>>> From: Andre Somers <[email protected]>
>>>> To: [email protected]
>>>> Sent: Tue, March 1, 2011 3:39:35 AM
>>>> Subject: Re: [Qt-qml] Is QML ready for 'production' purposes?
>>>>
>>>> Op Di, 1 maart, 2011 9:25 am, schreef Tim O'Callaghan:
>>>> > I've had this question come up, as a form of push-back to use QWidget,
>>>> > and and I'm curious to the 'official' line on this.
>>>>
>>>> That would depend on what you are producing, I think. Is it ready to
>>>> completely replace everything you did so far with widgets? No. Is it
>>>> ready
>>>> to use in scenarios where QML shines, like highly graphical, animated
>>>> interfaces that don't have to look native? Yes.
>>>>
>>>> André
>>>>
>>>>
>>>> _______________________________________________
>>>> Qt-qml mailing list
>>>> [email protected]
>>>> http://lists.qt.nokia.com/mailman/listinfo/qt-qml
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>>>
>>>
>>>
>>> _______________________________________________
>>> Qt-qml mailing list
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>>>
>>>
>>
>>
>> --
>>
>>
>> Mario Negro Ponzi
>> Mobile: +31.6.3456.1669
>> Address: Kogerwatering 2, 1541XC, Koog aan de Zaan
>>
>>
>> _______________________________________________
>> Qt-qml mailing list
>> [email protected]
>> http://lists.qt.nokia.com/mailman/listinfo/qt-qml
>>
>>
>


-- 


Mario Negro Ponzi
Mobile: +31.6.3456.1669
Address: Kogerwatering 2, 1541XC, Koog aan de Zaan
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