Product as addon & it's own product....?

[saasideas]

I have the following issue:

 

A product which can be purchased on it's own (only applies to a single domain, so multiple instances can be purchased) but i also want a user to be able to choose it for a hosting package and the current domain they're using for it. So during ordering/configuring a hosting package I want them to be able to easily tack on this additional product.

 

I've configured it as an addon for a hosting package, and as a seperate product so multiple instances can be purchased. This way if the user's want to purchase additional ones because they have multiple sites on one server they can. I guess I need to write my own action hook to say "when this addon is used, add the appropriate product to the shopping cart". I've set the addon to 0.00$ so duplicate pricing won't get done. Can you point me to the documentation and action hook(s) I need to use to trigger an add to cart of the product when the addon shows that I need to?

 

Support mentioned http://docs.whmcs.com/Hooks:Order_Process but I'm not really sure which one of those fit or the best way to accomplish what I need to.

 

It doesn't look like product bundling is what I want/need and there's no easy way to easily allow a user to add additional products based on the product they are purchasing. Based on what I've seen in the action hooks it doesn't look like it has what I need? all the order hooks are for modules...?

 

If anyone can help that would be great, thanks.