I can inspect values but cannot change properties.

[huy-le]

I integrated successfully. But I am unable to change any properties. Is there any flag I need to turn on?

[nguyenhuy]

Which properties are you trying to edit? Some properties are not editable due to their characteristics, like those belong to layout specs, because layout specs are (re)created on every measure pass (every time -layoutSpecThatFits: is called). Constrained sizes are also not editable because they are usually influenced by other objects, like the collection/table delegate, or the parent layout element.