Swift Json Decodable data structure, varying values in single array

Question

what im working with

"meta_data": [
        {
            "id": 4116,
            "key": "_wcf_frm_created",
            "value": ""
        },
        {
            "id": 4117,
            "key": "_wcf_custom_degin_checkbox",
            "value": ""
        },
        {
            "id": 4118,
            "key": "_wcf_frm_data",
            "value": {
                "1": {
                    "1": "",
                    "2": "",
                    "3": "chk_box"
                }
            }
        },
        {
            "id": 4142,
            "key": "_vendor_select",
            "value": "6484"
        },
        {
            "id": 4143,
            "key": "_vendor_percentage",
            "value": "100"
        },
        {
            "id": 4144,
            "key": "_vendor_pro_cat",
            "value": "Sushi"
        },
        {
            "id": 4156,
            "key": "slide_template",
            "value": "default"
        }
    ],
    "_links": {
        "self": [
            {
                "href": "https://xxxxxx.net/wp-json/wc/v3/products/6489"
            }
        ],
        "collection": [
            {
                "href": "https://xxxxxx.net/wp-json/wc/v3/products"
            }
        ]
    }

what I currently have

struct woocomerceProduct : Decodable, Encodable
{
    var meta_data : [Meta_data?]
    var _links : [_Links?]


}

    struct Meta_data : Decodable, Encodable
{
    var id : Int?
    var key : String?
    var value : String?
}
   struct One : Decodable, Encodable
{
        var one : String?
        var two : String?
        var three : String?
}

struct _Links : Decodable, Encodable
{
    var SELF : [String?]
    var collectio : [String?]
}

ok so here are the questions. 1. id 4118. value goes from String to obj, how do I code this part? 2. it also uses a variable string "1","2"... I can't use integer as variable, so I spelled it out? should be ok. 3. The value here is self, I can't use a variable self cause it will think it's a self property. so I just capitalized this.

I looked at this, which i believe is something similar to what i need to do, but since this is between an object and an string, im not sure what i need to code here. Swift structures: handling multiple types for a single property

==> for SELF, you need to use coding keys. enum CodingKeys: String, CodingKey { case SELF = "self" } — Hobbit
– Hobbit, Commented Dec 14, 2019 at 16:22

Vasucd · Accepted Answer · 2019-12-14 16:07:58Z

4

Try this link for conversion of your json into Codable model link

    import Foundation

// MARK: - Welcome
struct Welcome: Codable {
    let metaData: [MetaDatum]
    let links: Links

    enum CodingKeys: String, CodingKey {
        case metaData = "meta_data"
        case links = "_links"
    }
}

// MARK: - Links
struct Links: Codable {
    let linksSelf, collection: [Collection]

    enum CodingKeys: String, CodingKey {
        case linksSelf = "self"
        case collection
    }
}

// MARK: - Collection
struct Collection: Codable {
    let href: String
}

// MARK: - MetaDatum
struct MetaDatum: Codable {
    let id: Int
    let key: String
    let value: ValueUnion
}

enum ValueUnion: Codable {
    case string(String)
    case valueClass(ValueClass)

    init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        if let x = try? container.decode(String.self) {
            self = .string(x)
            return
        }
        if let x = try? container.decode(ValueClass.self) {
            self = .valueClass(x)
            return
        }
        throw DecodingError.typeMismatch(ValueUnion.self, DecodingError.Context(codingPath: decoder.codingPath, debugDescription: "Wrong type for ValueUnion"))
    }

    func encode(to encoder: Encoder) throws {
        var container = encoder.singleValueContainer()
        switch self {
        case .string(let x):
            try container.encode(x)
        case .valueClass(let x):
            try container.encode(x)
        }
    }
}

// MARK: - ValueClass
struct ValueClass: Codable {
    let the1: [String: String]

    enum CodingKeys: String, CodingKey {
        case the1 = "1"
    }
}

edited Dec 14, 2019 at 16:07

answered Dec 14, 2019 at 14:25

Vasucd

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6 Comments

Zack Cheang Weng Seong Over a year ago

very interesting link, Ill try to use it, but this uses codable when we can use decodable, is there a decodable version? i guess it doesn't matter

Vasucd Over a year ago

Swift 4 version onwards support Codable protocol so it won't be problem.

Hovercraft Full Of Eels Over a year ago

Vasu, if you want to comment to someone, prepend the @ in front of their user name, for example, do "@PranavKasetti" to comment to Pranav.

Vasucd Over a year ago

@HovercraftFullOfEels okay

Zack Cheang Weng Seong Over a year ago

this worked, thanks for the link! would had saved me so much time if I had knew this ealier

|

vadian · Accepted Answer · 2019-12-14 12:10:49Z

0

Too many unnecessary optionals, too many unnecessary underscore characters.

To decode two different types an enum with associated types is reasonable.
The code decodes a dictionary [String:[String:String]].
To map inappropriate keys provide CodingKeys.

struct WoocomerceProduct : Decodable {
    let metaData : [Meta]
    let links : Links

    private enum CodingKeys : String, CodingKey { case metaData  = "meta_data", links = "_links" }
}

struct Meta : Decodable {
    let id : Int
    let key : String
    let value : StringOrDictionary
}

struct Links : Decodable {
    let myself : [URLType]
    let collection : [URLType]

    private enum CodingKeys : String, CodingKey { case myself  = "self", collection }
}

struct URLType : Decodable {
    let href : URL
}


enum StringOrDictionary : Decodable {
    case string(String), dictionary([String:[String:String]])

    init(from decoder : Decoder) throws
    {
        let container = try decoder.singleValueContainer()
        do {
            let stringData = try container.decode(String.self)
            self = .string(stringData)
        } catch DecodingError.typeMismatch {
            let dictionaryData = try container.decode([String:[String:String]].self)
            self = .dictionary(dictionaryData)
        }
    }
}

answered Dec 14, 2019 at 12:10

vadian

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7 Comments

Zack Cheang Weng Seong Over a year ago

I see here, you using let, instead of var, some values in meta data can be empty, will this work even you wrote let?

vadian Over a year ago

let is just a declaration as constant (immutable). If keys are missing declare the corresponding struct members as optional. By the way delete the Encodableconfomance if the structs will never be encoded.

Zack Cheang Weng Seong Over a year ago

imgur.com/a/DEybvQ3 if i remove the enum, it removes the error, can i move the enum somewhere else? Also, your seeing others because thats not all the api puts out. But your code is implemented at the bottom

vadian Over a year ago

My answer works with the given JSON in the question. It makes no sense if the real data is completely different. I will delete my answer later.

Zack Cheang Weng Seong Over a year ago

therefore my response was imgur.com/a/Pwbpzdz, thus i didn't add it into the overall question

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