Rails nested forms multiple layers deep
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I don't know the best way to label this but basically, I have 3 models,

Course: A subject, which has many Sessions
Session: Has many Slots that make up one session
Slot: Has a date and time which it happens on

The idea is, if you are interested in a Course, you register to take a Session. Each Session will have the same number of Slots, but these could be at different times of the month (e.g. you could take a 5 day session on the 30th July to 3rd Aug, or the same session a week later, 6th Aug to 10th Aug)

So I need to try and set up my nested for, so you can add or remove Sessions, each one should have the same number of nested Slots (based on a number in a drop down somewhere up the form).

Can anyone think of a nice way of doing this? or even a nasty way? I'm having trouble :)