How to modify some field when save a MonoBehavior?

I want to change some field of a MonoBehavior when I save it.
For example I have a UnityEngine.UI.Text. I want to add I18N support. That mean I can switch my language and change both the text and font of the Text. But when I save the GameObject, It need change to text and font field to null. This make sure the UI will not dependent on any specify language.

A MonoBehavior can saved in different ways. It usually saved into a prefab, but into a scene is also a reasonable way. Even more I can create a GameObject as a sub-asset of other assets.

And after I save it, I need revert and set the font and text field correctly, in order to preview.
I investigate some API like PrefabUtility.prefabInstanceUpdated, AssetPostProcessor, AssetModificationProcessor, ISerializeableCallback. All of them seems not suitable for this.

Is there any suggestion?

 

I wouldn't do that. First, it's an extra step you would need to do. Second, just use the defaults as fallback values. Define what is your fallback language (en/us for example), put everything in place with this language and then change these if it's needed.

Reason: if you mess up something and you don't have translations for certain things, you will see English text not nothing. It's an inch better.