iOS : Unbox JSON with array of dictionary array

Question

I want to parse a JSON file using Unbox library. The JSON is an array of dictionary array. How can we do that? I tried using keypath and all but unable to parse it. I need array of section.

I tried with single hierarchy and able to parse it.

Library used:https://github.com/JohnSundell/Unbox

{
    "content": [
    {
        "section": [
         {
            "title": "Test1"
         },
         {
            "title": "Test2"
         }
         ]
    },
    {
        "section": [
        {
            "title": "Test1"
        },
        {
            "title": "Test2"
        }
        ]
    }
    ]
}

struct Data : Unboxable {
    let title: String

    init(title: String) {
        self.title = title  
    }
    init(unboxer: Unboxer) throws {
        self.title = try unboxer.unbox(key: "title")
    }
}

let dataArray : Data = try unbox(data: Data(contentsOf: url!))

I have able to parse single hierarchy. But not able to parse array inside an array. — miOS, Feb 15 '18 at 15:25
Show your data structure and show what you have tried so far even for the single hierarchy if multiple hierarchy doesn't work. — nayem, Feb 15 '18 at 15:29
updated answer. There are mutiple files so can't send each and every code. — miOS, Feb 15 '18 at 15:34
Consider that there are 3 levels: First a root element (a dictionary) which contains a key `content`. The value for that key is an array of dictionaries. Each dictionary contains another array of dictionaries for key `section`. Each of these dictionaries contains a `title` key. Why do you use a third-party library? In Swift 4 everything comes out of the box. — vadian, Feb 15 '18 at 16:19

nayem · Accepted Answer · 2018-02-15T17:05:25.360

You will need some nested structs to hold all of the data available. The minimal data structure is something like:

struct MyData: Unboxable {
    let content: [Content]
    init(unboxer: Unboxer) throws {
        content = try unboxer.unbox(key: "content")
    }

    // Nested structure for holding `Content` type
    struct Content: Unboxable {
        let section: [Section]
        init(unboxer: Unboxer) throws {
            section = try unboxer.unbox(key: "section")
        }

        // Nested structure for holding `Section` type
        struct Section: Unboxable {
            let title: String
            init(unboxer: Unboxer) throws {
                title = try unboxer.unbox(key: "title")
            }
        }
    }
}

The example json and parsing strategy:

// Eventually, this is the data you maybe got from any server response
let jsonData = """
{
"content": [{
"section": [{
"title": "Test1"
},
{
"title": "Test2"
}
]
},
{
"section": [{
"title": "Test3"
},
{
"title": "Test4"
}
]
}
]
}
""".data(using: .utf8)!

// Now parse this 
do {
    let myData = try unbox(data: jsonData) as MyData
    print(myData.content[0].section[0].title) //Test1
    print(myData.content[0].section[1].title) //Test2
    print(myData.content[1].section[0].title) //Test3
    print(myData.content[1].section[1].title) //Test4
} catch {
    print(error)
}

Only for Swift 4 or later

If you aren't bound to the Swift version, there is even more simpler way to achieve this:

// Your data structure goes this
struct MyData: Codable {
    let content: [Content]

    struct Content: Codable {
        let section: [Section]

        struct Section: Codable {
            let title: String
        }
    }
}
// That's it

// Now you can parse the data like this:
do {
    let myData = try JSONDecoder().decode(MyData.self, from: jsonData)
    print(myData.content[0].section[0].title) //Test1
    print(myData.content[0].section[1].title) //Test2
    print(myData.content[1].section[0].title) //Test3
    print(myData.content[1].section[1].title) //Test4
} catch {
    print(error)
}

iOS : Unbox JSON with array of dictionary array

1 Answers1

Only for Swift 4 or later