Swift adding a reference to the owner of an object - reference

Question

For brevity, I am going to use some simple examples to illustrate my problem. So I currently have two classes:
Class Person and Class Pet
class Person:Codable {
var name:String
var pets:[Pet]?
}
class Pet:Codable {
var name:String
weak var owner:Person?
}
How would I add the owner reference of "Pet" if I am retrieving the data from a json?
JSON would be probably like this:
[
{
"name":"John",
"pets":[
{
"name":"Meow",
"owner":"John"
},
{
"name":"Woof",
"owner":"John"
}
]
}
]

Answer 1

Your JSON is an array of dictionaries, each dictionary representing a person. Each person dictionary itself has an array (associated with the key pets) and each entry in that array is a dictionary representing a pet owned by the person. Your question is how you set your pet -> person weak link, you don't say what you've tried. Here is some sample pseudo-code outlining how you would process this JSON:
parsedJSON = ... // parse the JSON using favourite method, returning an array of dictionaries
allPeople = new Array // place to store all the people
for each personDictionary in parsedJSON // iterate over every person dictionary
nextPerson = new Person // create a new Person
nextPerson.name = personDictionary["name"] // set the name
nextPerson.pets = new Array // create an array for the pets
for each petDictionary in personDictionary["pets"] // iterate over the pets
nextPet = new Pet // create a new Pet
nextPet.name = petDictionary["name"] // set its name
nextPet.owner = nextPerson // set its owner <- answer to your question
nextPerson.pets.add(nextPet) // add pet to person
end for
allPeople.add(nextPerson) // add completed person to allPeople
end for
// at this point allPeople has all the people, and each person
// has all their pets, and each pet has an owner
Now just code that up in Swift 4.
I'm open to changing the json structure as well
The above pseudo-code ignores the owner field for each pet, the pets are nested inside a person dictionary representing the owner so the owner field in a pet is just repeating that information and can be dropped form the JSON.
In your internal data structures having the (weak) back link to the owner might be useful so you can keep that, as the above pseudo-code does.
If you have trouble writing the above algorithm then ask a new question showing the code you've written, describe where your issue is, and someone will undoubtedly help you. Putting a reference to this question in your new one would also be helpful so people and read the history of your question and what you've already had answered.
HTH