Grind the chickpeas in a food processor until fine but not pastey and let them sit in the fridge for about 15 min.
Mix in the spices and optionally herbs.
Bring your falafel into shape and deep fry.
I'm not vegetarian or anything but it would feel weird adding gelatine to a vegan dish. On the other hand it's a very interesting idea. Maybe adding soaked chia, basil or linen seeds would help. They can store a lot of moisture.