Passing JSON in Swift 4

Question

Lets say that I am writing a class that is using a URLRequest to get some JSON data from an API.

When I get the data back I create a struct within a struct to represent the structure of the data:

File: Object.swift - Class File:

struct List: Codable {
    let policies: [Item]

    struct Item: Codable {
        let id: Int
        let name: String
    }
}

I then decode the JSON directly into a List item. I can then do whatever I want with it and the data is easy to access. But how can I pass it out of the class object. So lets say I want to do this in the main part of my code:

File: main.swift - Main part of code:

let myObject: Object = Object()

let dataList: List = myObject.getDataFromAPI()

for item in dataList.policies {
    print(item.name) 
}

Since the struct does not exist outside of the class function or class, how can I get the JSON data out of the object to do anything with? What is the right way to do this.

I think this is more of a how to program question than a I need a line of code.. but anyone who is willing to share some knowledge would be great!

Edited to clarify some points.

Ed

This question is to broad and not suitable for stackoverflow — Joakim Danielson, Aug 06 '18 at 18:17
@JoakimDanielson I suppose it is a broad question, but given that it should have a specific answer such as X or Y is the correct way to do this and here is some example code, and given that Swift 4 made large changes to how JSON is parsed perhaps this question can help others as well if answered? — Edward S., Aug 06 '18 at 18:24
@Purpose I have edited to clarify but in this case how would I return the struct out of the class method? Since the struct does not exist in main.swift? — Edward S., Aug 06 '18 at 18:28
@Purpose either inside getDataFromAPI() or inside Object.swift. I defined it because in the class I wanted to parse out the data.. but then its in this proprietary format and Im not sure how to access it from outside that method. — Edward S., Aug 06 '18 at 18:31
How do you want to access it from outside that method? You have to pass it out somehow, with the given format you parsed it with or with a format you define to be passed out. — Fabian, Aug 06 '18 at 18:35
@Purpose Id want to pass it out some way that made sense like an array or dictionary based on the shape of the data. But everything I found about parsing JSON seemed to indicate you had to create a struct. — Edward S., Aug 06 '18 at 18:37
If you want to return Dictionary, what about [this](https://stackoverflow.com/questions/30480672/how-to-convert-a-json-string-to-a-dictionary)? Why not return „proprietary format struct“? — Fabian, Aug 06 '18 at 18:41

score 0 · Answer 1 · answered Aug 06 '18 at 19:04

0

@Purpose provided me a clue in his comments but I found the answer here on another StackOverflow question:

accessing struct from one class to another

Turns out you can create it by doing:

variable: Object.struct = someValue

I had no idea!

answered Aug 06 '18 at 19:04

Edward S.

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Passing JSON in Swift 4

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