Large application design question

[Fredrik Melin]

I have a fairly large dll, it holds all business logic for our system.

To ease up programming, I use properties that loads "on demand", for sample

Invoice.Invoice_Rows always load when you load a invoice, but on
Invoice.Invoice_Rows(0) Item you have ParentInventory where the inventory
object is loaded (when you call it) and populated with correct product.

This easy up alot, For sample, you can do
Invoice.Invoice_Rows(0).ParentInventory.sProduct_I nformationAsHTML

Now to my problem, because we do it like this, I cannot split this dll in
several smaller, because basically every class is dependant on all others,
Invoice -> Invoice row -> Inventory -> Purchase -> Vendor and so on...

(I want to split the dll to ease up customization of parts of the system)

Could it be solved by creating a common Interface class that has all
interfaces for each class?
Is that the way to do it? Is there a better way?
If thats the way to do it, is there any way to ease up the creation of the
interface classes? (I have several hundred classes in the dll atm)

Regards
Fredrik Melin

[Nick]

Hi Fredrik,

Sounds like you have abig problem on your hands as the information within
your class libraries are not properly encapsulated.

I would agree that the use of Interface classes are the key to this, but
would also suggest that you also look into topics such as refactoring and
UML tools such as Rational Rose or Visio that help you visualise where youa
re and where you want to get to.

Regards,

Nick

"Fredrik Melin" <mel@no_spam_for_me.dacsa.net.nospam> wrote in message
news:ur*************@TK2MSFTNGP12.phx.gbl...

I have a fairly large dll, it holds all business logic for our system.

To ease up programming, I use properties that loads "on demand", for
sample

Invoice.Invoice_Rows always load when you load a invoice, but on
Invoice.Invoice_Rows(0) Item you have ParentInventory where the inventory
object is loaded (when you call it) and populated with correct product.

This easy up alot, For sample, you can do
Invoice.Invoice_Rows(0).ParentInventory.sProduct_I nformationAsHTML

Now to my problem, because we do it like this, I cannot split this dll in
several smaller, because basically every class is dependant on all others,
Invoice -> Invoice row -> Inventory -> Purchase -> Vendor and so on...

(I want to split the dll to ease up customization of parts of the system)

Could it be solved by creating a common Interface class that has all
interfaces for each class?
Is that the way to do it? Is there a better way?
If thats the way to do it, is there any way to ease up the creation of the
interface classes? (I have several hundred classes in the dll atm)

Regards
Fredrik Melin