Model casting for logged model events

[lairg99]

When logging model events, only enums and date casts are currently implemented. In my case, for example, I use a custom cast for a money object. The actual value is stored as an integer in the database, but the ActivityLog model stores this property in the array representation of the money object.

I would like to be able to handle the changes in exactly the same way as the actual model attributes. If necessary, I could even query relationships.

Some examples:

// Accessing an enum
$activity->changes()->old('interval')->label();
$activity->changes()->new('interval')->label();

// Accessing money object
$activity->changes()->old('amount')->formatTo('de_DE');

// Maybe accessing a relationship, when user_id was changed
$activity->changes()->old('user')->name;

What do you think?