How can I make a struct to decode JSON structure in Swift?

Question

How can I make a struct or class to decode following type of json structure in swift? I want to extract mainly the report node data !

{
    "earliest": "2020-10-17",
    "latest": "2020-10-28",
    "report": {
        "purchase": {
            "total": 1458600.0,
            "average": 121550.0,
            "min": 600000.0,
            "max": 1600.0
        },
        "sale": {
            "total": 434250.0,
            "average": 144750.0,
            "min": 360000.0,
            "max": 29250.0
        },
        "production": {
            "total": 792030,
            "average": 20308.46153846154,
            "min": 12000,
            "max": 29700
        }
    }
}

Answer 1

You just need to structure your data and conform it to Codable:

struct Root: Codable {
    let earliest: String
    let latest: String
    let report: Report
}

---

struct Report: Codable {
    let purchase: Results
    let sale: Results
    let production: Results
}

---

struct Results: Codable {
    let total: Int
    let average: Double
    let min: Int
    let max: Int
}

---

let json = """
{
    "earliest": "2020-10-17",
    "latest": "2020-10-28",
    "report": {
        "purchase": {
            "total": 1458600.0,
            "average": 121550.0,
            "min": 600000.0,
            "max": 1600.0
        },
        "sale": {
            "total": 434250.0,
            "average": 144750.0,
            "min": 360000.0,
            "max": 29250.0
        },
        "production": {
            "total": 792030,
            "average": 20308.46153846154,
            "min": 12000,
            "max": 29700
        }
    }
}
"""

---

do {
    let report = try JSONDecoder().decode(Root.self, from: .init(json.utf8)).report
    print("report", report)
} catch {
   print(error)
}

report Report(purchase: Results(total: 1458600, average: 121550.0, min: 600000, max: 1600), sale: Results(total: 434250, average: 144750.0, min: 360000, max: 29250), production: Results(total: 792030, average: 20308.46153846154, min: 12000, max: 29700))