Carrier module not displaying it's option unless a "regular" carrier is defined

[Nils-H]

I'm creating a shipping module that get's it options from a web service depending on the weight of the products in the cart. My problem is that the carrier module only displays its options when there's also defined a regular "static" carrier for the weight and zone. Is it not possible to display only shipping options from dynamic carrier modules?

 

I have not found any good tutorial or any documentation on creating carrier modules, so it's all by trial and failure so far. I really wish there was some description on the interface between prestashop and a carrier module, like what's the input, what is it supposed to render, and what is the output expected to the next step in the order process.

[Nils-H]

Deleted. Posted in the wrong thread.

Edited June 1, 2013 by Nils-H (see edit history)