For your information, here is Milbo's response to my request in the VM development forum:
[22:52:09] Reinhold Kainhofer: Is there anything special that I need to implement/handle in a shipping plugin to make it work properly in multivendor mode? In particular, one of my customers has multivendor mode enabled (says he needs it for his UPS shipping). As soon as he tries to restrict my shipping plugin to one vendor (using the vendor selection box in the shipment method config), the method is NEVER used, even for the selected vendor.
[22:52:11] Reinhold Kainhofer:
open-tools.net/forum/shipping-by-rules-p...ng-based-on-sku.html
[22:54:49] Milbo (Max Milbers): No, but the cart is always set to vendorId=1
[22:54:54] Milbo (Max Milbers): so it is never called
[23:07:28] Reinhold Kainhofer: Ah, so I'll tell the user that multivendor really needs a lot of custom coding to work.
[23:15:25] Milbo (Max Milbers): he wants multicart
[23:15:57] Milbo (Max Milbers): The logic to give the cart the vendor id of the first product was added and is quite simple
[23:16:10] Milbo (Max Milbers): the rest is to create another cart, per vendor
[23:16:21] Milbo (Max Milbers): to display this in a module or so and the rest is done
[23:16:27] Milbo (Max Milbers): almost lol
[23:16:50] Milbo (Max Milbers): If there are investors we can write and add it to the core
[23:25:32] Milbo (Max Milbers): he should write to me
[23:25:44] Milbo (Max Milbers): vm3 got already more features in this direction
[23:26:26] Milbo (Max Milbers): and maybe normographs multvendor already has it
If you want to get in touch with Milbo (the VM lead developer and CEO of iStraxx), it's probably best to post a request at:
virtuemart.net/contact-the-team
Best regards,
Reinhold