Development of Dynamic NHibernate

sergunok · **Joined:** Tue Aug 23, 2005 8:15 am **Posts:** 45

Hello guys!

I have a few ideas about the extending existing functionality of NHibernate. And would like to discuss them with you. This thread is primary targeted to people how knows the internals of NH.

Ideas are as folows (they were earlier published here:
http://nhibernate.sourceforge.net/forum ... ht=dynamic):

- make NH dynamic (1)
- add to NH classes versions support (2)

idea (1) addresses the feature to change the structure of data model dynamically without recompile source code.
idea (2) could allow keep data when the structure of classes changes

I think that (1) could be done by killing the relation NH class <-> C# class. Instead of using static c# classes it is possible to use dynamic objects with collection of properties, for example:

DynObject manager = new DynObject("Manager");
manager["Name"] = "John"

instead of:

Manager manager = new Manager();
manager.Name = "John";

What do you think: is it possible to port NH in this direction, does NH retrieve a lot of information about classes from reflection? Is it a big work?

instead of dynamic type names of classes could be used.

"Manager" instead of typeof(Manager)

(2) Issue.
NH could have versioning of structure feature.
Dont' have any ideas how. I think additional tables with version labels
could be added to the relation scheme.

Please feel free to discuss these ideas.

Best regards,
Sergey Gerasimov

sergey · **Posted:** Fri Sep 16, 2005 1:32 pm

1) should be possible to do with dynamic components, which I'm going to port from H2.1 in the near future.

sergunok · **Joined:** Tue Aug 23, 2005 8:15 am **Posts:** 45

I think that is very useful and powerful feature!

Much-much sorry for the next question:
but what is the approximate term when this functionality will be available (in first version)?

sergey wrote:

1) should be possible to do with dynamic components, which I'm going to port from H2.1 in the near future.

sergey · **Posted:** Sat Sep 17, 2005 10:38 am

I think one week at most, if I remember to do it :) Not much work is left there, I just need to port a few missing functions.

pedrojr · **Posted:** Mon Sep 19, 2005 10:18 am

Hi,

Necessary very of this! It was thinking about abandoning the NHibernate for the lack of this. Without a doubt this is a very important feature.

[]s

sergey · **Posted:** Mon Sep 19, 2005 10:20 am

Ok ok, it's in CVS already.

pedrojr · **Posted:** Fri Oct 14, 2005 7:53 pm

Hi!

This feature already is functioning?

Thanks.

KPixel · **Posted:** Sun Oct 16, 2005 7:45 am

Did you have any problem using it?
(if so, create a new topic in General Support)

pedrojr · **Posted:** Mon Oct 17, 2005 8:24 pm

It would like to know if it is implemented therefore I did not find nothing the respect in the documentation.

Thanks.

k-dub · **Joined:** Thu May 12, 2005 8:45 am **Posts:** 226

I must be missing something. This doesn't look much different from ADO.NET, with the string-keyed indexer and all that.

Code:

DynObject manager = new DynObject("Manager"); 
manager["Name"] = "John"

// the DBA renames the "Name" column to "FullName"

// the code breaks !!

I must be missing something. This doesn't look like a good idea.

TheShark · **Joined:** Thu Aug 25, 2005 3:35 am **Posts:** 160

the idea of objects is that (amongst others) you wish to work typed.
You are basically suggesting a hashtable.

I agree with k-dub, this is not a good idea.