Create extension in Swift 5 for Dictonary[String:Any] - ios

Question

I want to create extension for Dictionary [String:Any] which is received from API Response.
Right Now I am doing below way
I have created func getDataFromJson this is working fine, Please let me know how to do that.
func getDataFromJson(json: AnyObject) -> Data?{
do {
print("json = \(json)")
return try JSONSerialization.data(withJSONObject: json, options: JSONSerialization.WritingOptions.prettyPrinted)
} catch let myJSONError {
print("\n\n\nError => getDataFromJson => \(myJSONError)")
}
return nil;
}
This is my response and I want to "data" to Data
{
"status": true,
"message": "Country List",
"data": [
{
"id": 1,
"name": “ABC”,
"code": "A",
"phone_code": "+91”,
"flag": "country-flags/-shiny.png"
},
{
"id": 2,
"name": “ZYX”,
"code": “Z”,
"phone_code": "+1”,
"flag": "country-flags/-shiny.png"
}
]
}
I want to get data this way jsonResponse["data"].retriveData()

Answer 1

Here is a simple function that encodes the dictionary, the function throws any error so it can be properly handled. Since JSONSerialization.data(withJSONObject: takes an Any parameter this function can also be implemented for an array etc
extension Dictionary {
func retriveData() throws -> Data {
return try JSONSerialization.data(withJSONObject: self)
}
}
Simple example
let dict = ["abc": 123, "def": 456]
do {
let data = try dict.retriveData()
let result = try JSONDecoder().decode([String:Int].self, from:data)
print(result)
} catch {
print(error)
}
Another way is to use Result if you're on Swift 5 (shortened after comment from vadian)
extension Dictionary {
func retriveData() -> Result<Data, Error> {
return Result { try JSONSerialization.data(withJSONObject: self) }
}
}
and an example
let result = try dict.retriveData()
switch result {
case .success(let data):
let dictionary = try JSONDecoder().decode([String:Int].self, from:data)
print(dictionary)
case .failure(let error):
print(error)
}

Answer 2

a copy of your function transposed to an extension can be
extension Dictionary {
func retriveData() -> Data? {
do {
return try JSONSerialization.data(withJSONObject: self, options: .prettyPrinted)
} catch let myJSONError {
print("\n\n\nError => getDataFromJson => \(myJSONError)")
}
return nil
}
}

Answer 3

Correct json
{
"status": true,
"message": "Country List",
"data": [
{
"id": 1,
"name": "ABC",
"code": "A",
"phone_code": "+91",
"flag": "country-flags/-shiny.png"
},
{
"id": 2,
"name": "ZYX",
"code": "Z",
"phone_code": "+1",
"flag": "country-flags/-shiny.png"
}
]
}
Model
struct Datum: Codable {
let id: Int
let name, code, phoneCode, flag: String
}
Decoding data only
let str = """
{
"status": true,
"message": "Country List",
"data": [{
"id": 1,
"name": "ABC",
"code": "A",
"phone_code": "+91",
"flag": "country-flags/-shiny.png"
},
{
"id": 2,
"name": "ZYX",
"code": "Z",
"phone_code": "+1",
"flag": "country-flags/-shiny.png"
}
]
}
"""
do {
let dic = try JSONSerialization.jsonObject(with: Data(str.utf8)) as! [String:Any]
let content = try JSONSerialization.data(withJSONObject: dic["data"])
let dec = JSONDecoder()
dec.keyDecodingStrategy = .convertFromSnakeCase
let res = try dec.decode([Datum].self, from: content)
print(res)
}
catch {
print(error)
}

Answer 4

Please try this
// Response Dictionary
let jsonResponse : [String:Any] = ["data":["key1":"value1",
"key2":"value2",
"key3":"value3",
"key4":"value4"]]
// check dictionary contains value for key "data"
if let dataDict = jsonResponse["data"] as? [String:Any] {
// convert dictionary to data
let jsonData = dataDict.retriveData()
print("Json Data :- ", jsonData != nil ? "Success" : "Data is nil")
}
// Dictionary exxtension for converting dictionary to json data
extension Dictionary {
func retriveData() -> Data? {
do {
print("json = \(self)")
return try JSONSerialization.data(withJSONObject: self, options: JSONSerialization.WritingOptions.prettyPrinted)
} catch let myJSONError {
print("\n\n\nError => getDataFromJson => \(myJSONError)")
}
return nil;
}
}