Fallback for no products in a product set

[andrewhoule]

I'm using the buybutton JS. I've got product sets rendering just fine when their are products in a collection. However, when a collection is empty, I'm getting a JS 'Not Found' error. How can I suppress that error, and just display a div with something along the lines of "`collection name` products not available at this time" message if no products are in a collection.

I've Googled, til I could Google no more looking for a way to handle that situation. 

How can I hook into the API to check if no products are available, and if no products then display this fallback template?

Thanks in advance!