[Solved] How to prevent recompile to see QML-changes?

[kaivolde]

Hi folks,

I have the following (standard) project-setup:
main.cpp-file which loads then main.qml-file
some qml-files which are placed in a resource-file (qrc)
I have done some qml-extensions in c++ how it is described here: http://qt-project.org/doc/qt-5/qml-extending-tutorial-index.html

Problem: If I do a change in a qml-file, I don't see an effect, if I just restart the application (in Creator). I always have to recompile the code. I would expect this behaviour for changes in the C++-code, but for the QML?

What am I doing wrong?

Thanks in advance.
Best regards Kai

[leonardo.ramosantos]

Hi there.

This happens because the qml file you are editing is inside the resource file. Resource files are compiled and stay inside executable. Thus, when you modify a qml that is within resource file, the compiler needs to recompile the resource file to put within executable and recompile the executable.

I hope I have helped you.

[kaivolde]

So,

during development it's not a good idea to put qml's into qrc's.

Thanks a lot. Best regards
Kai

[Rolias]

I don't know, I like putting my qml into the qrc during development. I just click on the (big green) run button after making QML changes and it saves, compiles and builds in a few seconds so I don't consider it a hardship. At one point nested QML wasn't automatically rebuilding but in the latest releases it works. The compile only builds what it needs to (as opposed to a rebuild), so it's typically pretty fast in my experience.

[Torgeir]

I also put qml files into qrc right from the start.

In addition I hook up a shortcut F5 to reload qml from disk. This way I can edit qml files and instantly see the changes in the running application.

My shortcut reload slot has the lines

@
view->engine()->clearComponentCache();
view->setSource(
QUrl::fromLocalFile("c:/path/to/main.qml"));
@

It's after setting up this you really get to experience the Quick in QtQuick :-)
I used to believe it was about rendering performance, but it's as much about developer productivity.

[kaivolde]

Thanks again, it is always a pleasure to get such qualified answers.

• I had this strange misbehaviour, which I described in my first post.
• To test the problem again, I started the same project from scratch.
  This time the problem did not occur. So I was able to see my
  QML-changes at once without recompile. So I think I had a
  misconfiguration in my old project or there is a (little) bug somewhere
  in the build-system.
• @Rolias: Same with me. Having the qml's in the qrc is comfortable. You
  don't have to care for file locations and so on.
• @Torgair: If I understand correctly, you bind the shortcut into every
  application which you develop, so you can edit and test your qml at
  runtime. Is it correct? Perfect trick.

Thanks again
Kai