To Ulf’s point,
You would indeed not be able to restore a previous value using text:
fooObject?.title ?? text because it will have been overwritten whenever
fooObject?.title yields a valid value.
The most reasonable solution therefore is to use the Binding element which is
designed to restore the previous/original binding or value of the binding
target property whenever its “when” property is false.
It isn’t the most concise but it is bomb-proof and explicit, and is fully
aligned to your requirements.
Text {
id: yourTextObject
text: "defaultString" // default binding when fooObject !== null; this
could itself be a binding to some other default property.
Binding {
yourTextObject.text: fooObject.title // assuming title will be valid if
fooObject !== null, if not the “when” property might need fooObject?.title
when: fooObject // else it will be restored to being bound to the
“defaultString" value
}
}
Kind regards,
Mike--
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