CODEWITHSUNDEEP
arraysswiftstructsave
Matus Hmelar
Matus Hmelar

Reputation: 448

Whats the best practice to save and load array of struct?

I am looking for advice to save my array of structures, so they are available at start and can be easily accessed and updated.

All tutorials I have watched have only 1 instance of struct, so I keep failing on implementing array of structures.

Structure of data is:

    struct Stock : Codable {
        let ticker : String
        let amount : Double
        var boughtAt : Double
        var totalValue : Double
        var realTimePrice : Double
        var float : Double
        var type : String
    }

    var stocksArray = [Stock]()

Upvotes: 1

Views: 1209

Answers (2)

PGDev
PGDev

Reputation: 24341

Since your struct Stock conforms to Codable, you can easily store the array [Stock] in UserDefaults as data using JSONEncoder, i.e.

var stocksArray = [Stock]()
do {
    let data = try JSONEncoder().encode(stocksArray)
    UserDefaults.standard.set(data, forKey: "stocksArray")
} catch  {
    print(error)
}

Similarly, you can fetch from UserDefaults using JSONDecoder like,

if let data = UserDefaults.standard.data(forKey: "stocksArray") {
    do {
        let arr = try JSONDecoder().decode([Stock].self, from: data)
        print(arr)
    } catch {
        print(error)
    }
}

This is one way to store your array. There are other ways as well - CoreData, File etc.

Upvotes: 2

Vatsal Shukla
Vatsal Shukla

Reputation: 1272

In my opinion, You can convert your Struct to Dictionary type and add that dictionary in to NSArray and save that array to Document directory of phone.

Example,

struct Stock {
    var ticker : String = ""
    var amount : Double = 0.0
    var boughtAt : Double = 0.0
    var totalValue : Double = 0.0
    var realTimePrice : Double = 0.0
    var float : Double = 0.0
    var type : String = ""

    var json:Dictionary<String,Any> {
        set{
            self.ticker = newValue["ticker"] as! String
            self.amount = newValue["amount"] as! Double
            self.boughtAt = newValue["boughtAt"] as! Double
            self.totalValue = newValue["totalValue"] as! Double
            self.realTimePrice = newValue["realTimePrice"] as! Double
            self.float = newValue["float"] as! Double
            self.type = newValue["type"] as! String
        }
        get {
            return ["ticker":self.ticker,"amount":self.amount,"boughtAt":self.boughtAt,"totalValue":self.totalValue,"realTimePrice":self.realTimePrice,"float":self.float,"type":self.type]
        }
    }

    init(withJSON json:Dictionary<String,Any>) {
        self.json = json
    }
}
//Now, get dictionary from object and add it into array.
let stock = Stock(withJSON: [:])
let json = self.stock.json
let array = NSArray(arrayLiteral: json)

//Now, you can save NSArray to file.
array.write(toFile: "file path.plist", atomically: true)

//You can get array from plist file,
let array = NSArray(contentsOfFile: "file path.plist")

Upvotes: 0

Related Questions