I would say :
Have a Table 'Comments'
A Comment has a FK to an item.
2 solutions :
1° The simpliest, if you ONLY have to do this on fly page.
-> Your 'Fly' page of 'Item',
is now a 'Form' page of 'Comment'
-> This form receive a value for 'Item'
do it with a filter, so this filter value will be recieved through url. (&filter_item=xxx)
-> For the moment, let the combo for item selection, then transform it in hidden field, when everything works
-> Merge the item fly inside the form page.
If the filter_item is setted, load an item model based on this ID and the fly shows up with theses informations.
-> Below, in the form, you keep your text zone for filling up a comment.
-> This technique can be used to edit the comment.
Try this first, because the second way is more complex and can be done in 2 different ways.
The second solution is better because cleaner. You stay in the Item view to add a comment and is it better than going to a 'Comment' view. Much better.
If you are experienced in dev, choose the second technique, and let's talk about it.
If you are in hurry, do this one explained here, wich you can realize in 20 minutes.
The best here is AJAX, anyway. Because Joomla has difficulties to receive multiparts forms in native, so Ajax is a good workaround, and nice user experience.
Have fun. I am busy, but enjoy to help.
The real meaning of life.
