I took a rather esoteric and strange route for this project. I thought it would be fun to make a demon summoning app. While the coding of it was straightforward, figuring out the ActiveRecord associations was surprisingly difficult, and is what caused the most problems.
I knew I needed a Demon model and a User model. The users would summon demons – therefore there should be a summon model as well. But what does the summon model require? Presumably some ingredients people would use in summoning. I originally thought of this as just a simple array that you can update in the database. But as my instructor pointed out, it might be best as another model. With that in mind – I created a Sacrifice model that belongs to both a demon and a summon.
A user has many demons through summonings. A demon has many users through summonings as well. A summons has a demon and a user, as well as a sacrifice. A demon can have many sacrifices. A sacrifice has many summons but only one demon.
Looking at it this way I was able to see which routes worked bested as nested routes. A summons should be called from a user who can choose what demon they want or a specific demon someone found on the index page. However, getting to the point where I understood the relationships best took a bit of back and forth, and some rollbacking of migrations as well. While I wish I could’ve had a clearer vision so that I didn’t need to do so much revision with the database, I’m not sure if it’s always going to be avoidable.
In any case – summonings ahead!