Check if PFObject is in PFRelation

Question

I am building an iOS in Swift using Parse.com as my backend.

I have a table of objects: car, and each car can be owned by multiple users, so I have a Car table with the column owners which is a PRRelation of the _User table.

I am displaying all the cars in a TableView and want to determine (for each object) whether the PFUser.currentUser() is in the Relation of _User objects for each car.

Is there a way of doing this without creating a query which then makes a request to the Parse server? Doing that seems very inefficient to have to check again for each object, and would make a large number of Parse database calls which would make me hit the call limit quite quickly if multiple people are using the app...

So is there a way to simply do something like:

if carObject["owners].contains(PFUser.currentUser()) {

   println("the current user is an owner of this car")

}

Might it be possible to run a query of all cars, and then another query of all the cars with a whereKey restriction on the students column and then comparing queries? How could I compare the queries?

Answer 1

Have you created your car class in your app? You can download all your car objects from parse at once, put them in an [Car] and then you'll have all the relational data as well.

I'm not 100% sure but you may need to use parsequery.includeKey("users") when you query parse so it also includes the parse user. User's being an attribute of Car.