We have following two types of business connections: customers and suppliers.
Each of them have their own website which allows them to interact with us (b2b).
Now we are developing a plattform on that the suppliers (sellers) can create offers which are listed on the customers (buyers) site.
The design of the plattform for each site is identical and only differs in a few points depending on if it's an buyer or a seller. For example: On an offer-page only the buyer can buy.
To prevent double code I created a new website where the whole customer<->supplier shopping thing is handled.
We're thinking about to integrate the two parts of the shopping plattform in each of the designated webs (customer-web / supplier-web).
My problem is that I don't have any good idea how to prevent the code of the website from duplicating.
I had following ideas:
iFrame in each site with automatic login-share over tokens. -> I don't like this idea because I don't like iFrames.
Compile the pages into dll's and refer the dll's in each web. -> I have no idea if this is possible. I did not find anything pretty useful for this idea.
So my question is: Are there other/better ways to realise my demant? For me it's important to avoid double code. It also shouldn't be to much afford if possible (so reprogramming the pages into UserControls is no way for me since this is a lot of effort and it's hard to make changes).