check if any property in an object is nil - Swift 3

Question

Im using Swift 3

Wondering whether any method is available to check if all the properties in an object has value / nil

Eg:

class Vehicle {
var name : String?
var model: String?
var VIN: String?
}

let objCar = Vehicle()
objCar.name = "Volvo"

if objCar.{anyProperty} ! = nil {
//Go to other screen
}

Im in search of the {anyProperty} method where it returns true only if I have values for all properties of objCar. In our case, objCar has no model and VIN and so {anyProperty} is false and will come out of if loop

Pls advice

Answer 1

I would strongly recommend against this. State validation is something which should happen from inside a class. From inside the class, you should know better how to check validity.

class Vehicle {
    var name: String?
    var model: String?
    var VIN: String?

    func isReadyToAdvance() -> Bool {
        return name != nil && model != nil && VIN != nil
    }
}

let objCar = Vehicle()
objCar.name = "Volvo"

if objCar.isReadyToAdvance() {
    // Go to other screen
}

If there are subclasses with different rules for isReadyToAdvance() they can override that method.

---

If isReadyToAdvance() doesn't make sense for the base class, then add it as an extension.

extension Vehicle {
    func isReadyToAdvance() -> Bool {
        return name != nil && model != nil && VIN != nil
    }
}

---

@iPeter asked for something a bit more compact when there are lots of properties.

extension Vehicle {
    func isReadyToAdvance() -> Bool {
        // Add all the optional properties to optionals
        let optionals: [Any?] = [name, model, VIN]
        if (optionals.contains{ $0 == nil }) { return false }

        // Any other checks

        return true
    }
}