QML should allow the declaration of private properties

As a QML component developper, I often need private properties, that are needed for my component to work, but that should not be eexposed to the component user.

For example :

import Qt 4.7

TextInput {
	signal endEditing(bool changed)

	property string oldText		//I'd like to make this private

	/*					// Workaround
	QtObject {
		id: privateVars
		property string oldText
	}
	*/

	onFocusChanged: {
		if (focus) {
			oldText = text;
		} else {
			if (text != oldText)
				endEditing(true);
			else
				endEditing(false);
		}
	}

}

So I'd suggest that it would be helpful if we had a way to mark a property as private.

I discussed about that on #qt-qml and Michael Brasser suggested:

we've also discussed this in the past in the Brisbane office; one unresolved question has been what exactly private should mean – obviously it means inaccessible to users of the component, but what about sub-components of the component, etc? If there isn't already something in JIRA for it, I'd suggest adding it, and we can look into more for a future release. Your workaround is exactly what we suggest at the moment