Invalid top-level type in JSON write'

ios, json, swift

Solution

Your json has some wrong format.Use a dictionary is much clear than json in swift, and use JSONSerialization to convert the dictionary to json string.

The code looks like this:

func addtocartapicalling ()
{
    let headers = [
        "cache-control": "no-cache",
        "postman-token": "4c933910-0da0-b199-257b-28fb0b5a89ec"
    ]

    let jsonObj:Dictionary<String, Any> = [
        "cartType" : "1",
        "cartDetails" : [
            "customerID" : "sathish",
            "cartAmount" : "6999",
            "cartShipping" : "1",
            "cartTax1" : "69",
            "cartTax2" : "",
            "cartTax3" : "",
            "cartCouponCode" : "",
            "cartCouponAmount" : "",
            "cartPaymentMethod" : "",
            "cartProductItems" : [
                "productID" : "9",
                "productPrice" : "6999",
                "productQuantity" : "1"
            ]
        ]
    ]

    if (!JSONSerialization.isValidJSONObject(jsonObj)) {
        print("is not a valid json object")
        return
    }

    if let postData = try? JSONSerialization.data(withJSONObject: jsonObj, options: JSONSerialization.WritingOptions.prettyPrinted) {
        let request = NSMutableURLRequest(url: NSURL(string: "http://expapi.php")! as URL,
                                          cachePolicy: .useProtocolCachePolicy,timeoutInterval: 10.0)
        request.httpMethod = "POST"
        request.allHTTPHeaderFields = headers
        request.httpBody = postData

        let session = URLSession.shared
        let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
            if (error != nil) {
                print(error)
            } else {

                DispatchQueue.main.async(execute: {

                    if let json = (try? JSONSerialization.jsonObject(with: data!, options: [])) as? Dictionary<String,AnyObject>
                    {
                        let status = json["status"] as? Int;
                        if(status == 1)
                        {
                            print("SUCCESS....")
                            print(json)
                            if let CartID = json["CartID"] as? Int {
                                DispatchQueue.main.async(execute: {

                                    print("INSIDE CATEGORIES")
                                    print("CartID:\(CartID)")
                                    self.addtocartdata.append(Addtocartmodel(json:json))
                                })
                            }
                        }
                    }
                })
            }
        })

        dataTask.resume()
    }
}

Problem

I am passing some parameter to api , to done add to cart function. But when i pass the parameter , it showing the crash `Invalid top-level type in JSON write'` i know there is the problem in my passing parameter . Please help me out!.How to do that.Please help me out !!! This is the json format of parameter i am passing !!: ``` { "cartType" : "1", "cartDetails" : { "customerID" : "u", "cartAmount" : "6999", "cartShipping" : "1", "cartTax1" : "69", "cartTax2" : "", "cartTax3" : "", "cartCouponCode" : "", "cartCouponAmount" : "", "cartPaymentMethod" : "", "cartProductItems" : { "productID" : "9", "productPrice" : "6999", "productQuantity" : "1" } } } ``` My updated solution : ``` func addtocartapicalling () { let headers = [ "cache-control": "no-cache", "postman-token": "4c933910-0da0-b199-257b-28fb0b5a89ec" ] let jsonObj:Dictionary<String, Any> = [ "cartType" : "1", "cartDetails" : [ "customerID" : "sathish", "cartAmount" : "6999", "cartShipping" : "1", "cartTax1" : "69", "cartTax2" : "", "cartTax3" : "", "cartCouponCode" : "", "cartCouponAmount" : "", "cartPaymentMethod" : "", "cartProductItems" : [ "productID" : "9", "productPrice" : "6999", "productQuantity" : "1" ] ] ] if (!JSONSerialization.isValidJSONObject(jsonObj)) { print("is not a valid json object") return } if let postData = try? JSONSerialization.data(withJSONObject: jsonObj, options: JSONSerialization.WritingOptions.prettyPrinted) { let request = NSMutableURLRequest(url: NSURL(string: "http://expapi.php")! as URL, cachePolicy: .useProtocolCachePolicy,timeoutInterval: 10.0) request.httpMethod = "POST" request.allHTTPHeaderFields = headers request.httpBody = postData let session = URLSession.shared let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in if (error != nil) { ///print(error) } else { DispatchQueue.main.async(execute: { if let json = (try? JSONSerialization.jsonObject(with: data!, options: [])) as? Dictionary<String,AnyObject> { let status = json["status"] as? Int; if(status == 1) { print("SUCCESS....") if (json["CartID"] as? Int?) != nil { DispatchQueue.main.async(execute: { print("INSIDE CATEGORIES") self.addtocartdata.append(Addtocartmodel(json:CartID)) }) } } } }) } }) dataTask.resume() } } ``` last problem in append the values : In my model data class is look like this : ``` class Addtocartmodel { var cartid : Int? init(json:NSDictionary) { self.cartid = json["CartID"] as? Int } } ```

Original source