Perhaps a qt5.1 bug
with Qt5 when in a ui file for a property an empty string is set:
then calling the designer will trigger my appropriate routine in my custom widget
however when loading the file with the QuiLoader the property write routine will not be called.
In Qt4.8.4 the routine was called.
Is this a new feature (unwanted) or a bug or one has to do something special ?
more precise description:
I have a designer plugin with custom widgets. In one of my widgets a string property is initialized with a non empty string and write and read routines are defined for it.
I call the designer and when I drag my custom widget to the window I want to design, at that moment the property will have my default string.
In case I change that string or empty it and then create the ui file, the property in the ui file has the value I put in (empty or not) while the write routine is automatically called
When I call the designer again with the ui file, that property has therefore the right value (empty or not)
However when in my application program, I call the QuiLoader with the ui file , then for the non empty string the write routine is not called int Qt5.1 as was in Qt4.8.4 and previous, but for a non-empty string the routine gets called normally.
This sound like a regression, you should ask on the interest mailing list, you'll find Qt's developers/maintainers there (this forum is more user oriented)
Maybe first check the "bug report system":http://bugreports.qt-project.org/issues/ to see if someone else came across this problem.