Not Evaluated Description
Say, I'm a bad guy who doesn't read the docs. I came up with the following code:
import sys from PySide6.QtWidgets import QApplication, QWidget, QWizard, QWizardPage class WizardPage1(QWizardPage): def __init__(self, parent: QWidget | None = None) -> None: super().__init__(parent) self.registerField("fieldName", self) def someFunction(self) -> None: # QWizard::setField: Couldn't write to property '' self.setField("fieldName", "Guido") print("field set from", self.__class__.__name__) class WizardPage2(QWizardPage): def __init__(self, parent: QWidget | None = None) -> None: super().__init__(parent) def someFunction(self) -> None: print(self.field("fieldName"), "read from", self.__class__.__name__) class Wizard(QWizard): def __init__(self, parent: QWidget | None = None) -> None: super().__init__(parent) wp1 = WizardPage1(self) self.addPage(wp1) wp1.someFunction() wp2 = WizardPage2(self) self.addPage(wp2) wp2.someFunction() if __name__ == "__main__": app = QApplication(sys.argv) w = Wizard() # w.exec() # to see that it still works app.exit(0)
Here, I register a field without specifying a property. The widget is not in the list of the known ones, therefore the code should fail with a TypeError or something like that.
So, why doesn't it?
Instead, I get
QWizard::setField: Couldn't write to property ''
in the stderr, and still, the data is passed between the pages.
So, why to warn, then?
Instead, I can pass a name of a non-existing property:
self.registerField("fieldName", self, "nonExistingProperty")
This time, I get a slightly different stderr, but the data appear to pass between pages, too.
QWizard::setField: Couldn't write to property 'nonExistingProperty'
So, where are the data stored to?
I can even enter an illegal property name:
self.registerField("fieldName", self, "a badly named property")
But, despite the warning, the data is here. According to what stderr shows this time, the property name is unchanged:
QWizard::setField: Couldn't write to property 'a badly named property'
So, does QWizard.setField ever fail?