[Nitro] Og Editing Context

[Michael Neumann]

Hi,

Would it be possible to introduce an editing context, where you can 
register those objects that should be saved (with possible dependency 
resolving). Example:

class Book; end # forward

class Author
   property :name, String
   has_many :books, Book
end

class Book
   belongs_to :author, Author
   ...
end

########

a = Author.new
a.name = "Michael"
b = Book.new
a.add_book(b)

The problem here is, that the author must exist, before we can add a 
book to it (add_book will store the author to the database if it's not 
yet saved). Problem: You can't undo this. And it's not very clear, that 
add_book will save the author to database.

ed = EditingContext.new
a = Author.new
ed.add(a)
a.name = "Michael"


b = Book.new
ed.add(b)
a.add_book(b)

# everything is correct linked in memory, but not yet saved to database
b.author #=> a

# save all registered objects. this is done in correct order,
# so first a then b (the order can be infered automatically)
ed.save!

Alternatively, could we modify add_book so that it only assign the 
book.author_oid to the author object (not it's oid, as we don't have one 
yet), and not saves the author object to database. book.save would then 
query author.oid (if the author is already stored) or else raise an 
error. Even better, if author.save would trigger books.each {|b| b.save} 
in it's save method.

This is *very* useful for advanced scaffolding, where you want to add 
e.g. a new phone-number to a person, but not save it to database, yet, 
as we can cancel the whole "create Person" process.

Hope you get the point I'm trying to explain.

Regards,

   Michael