I understand that custom properties without a value disappear when they are not set to persistent, but the manual says the exception to this rule is bound properties. I think I found a bug that involves object type custom properties.
To recreate this issue:
- Create a custom property on a view that is an object type.
- Create two keys for this object and bind one of them to a tag. Leave property as transient.
- Save the view and close.
- Re-open the view, only the un-bound key will still be visible.
The object still shows there is a binding, but it is not visible. If you add another key to the object, the first key will re-appear. Setting the key to persistent will fix the issue, but I still think this is a bug.
This bug only seems to effect object type properties. Array and value types seem to work fine.
This was tested in Ignition 8.1.0.