How to decode the url about json data? - ios

Question

I got json data from server like this.
[
"http:\/\/helloWord.com\/user\/data\/000001.jpg?1497514193433",
"http:\/\/helloWord.com\/user\/data\/000002.jpg?1500626693722"
]
And What should I do to get each user url?
I try to use removingPercentEncoding, but it doesn't work.
What should I do?
Thanks.
let string:String = chatroom.avatar
let tempArr = string.components(separatedBy: ",")
var stringArr = Array<String>()
print("**tempArr\(tempArr)")
for a in tempArr {
var b = a.replacingOccurrences(of: "\"", with: "")
b = b.replacingOccurrences(of: "[", with: "")
b = b.replacingOccurrences(of: "]", with: "")
b = b.removingPercentEncoding //not working!!!!
print("b: \(b)")
//b: http:\/\/helloWord.com\/user\/data\/000001.jpg?1497514193433
//b: http:\/\/helloWord.com\/user\/data\/000002.jpg?1500626693722
}
I use swiftyJson
class User : Model {
var url:String = ""
func fromJson(_ json:JSON) {
url = json["url"].zipString
saveSqlite()
}
}
extension JSON {
var prettyString: String {
if let string = rawString() {
return string
}
return ""
}
var zipString: String {
if let string = rawString(.utf8, options: JSONSerialization.WritingOptions.init(rawValue: 0)) {
return string
}
return ""
}
}

Answer 1

Err, you shouldn't try to write your own JSON parser.
Try: https://github.com/SwiftyJSON/SwiftyJSON
It is one file of Swift code and makes using JSON much easier in Swift.
In swift 4 you will be able to use Structs to directly decode, but we're not there yet.
The apple way:
func read(payload: Data) throws -> [String]? {
guard let result = try JSONSerialization.jsonObject(with: payload, options: JSONSerialization.ReadingOptions.allowFragments) as? [String] else { return nil }
return result
}
Then for example you could read them out this way:
var userURLs: [URL] = []
for jsonURL in result {
guard let userURL = URL(string: jsonURL) else { continue }
userURLs.append(userURL)
}
This way you get only valid URL objects in your last result array.
If you get problems using the JSONSerialization code I described above it might be that it expects a different type. Then you'd have to use [Any] as a cast instead, or in case you have objects [String: Any] usually works. Keep in mind that in that case you will have to cast the objects you get from the array like so:
URL(string: (jsonURL as? String) ?? "")
Swifty JSON makes it easier to go about with the nullability, as it provides an easy way to safely traverse an object tree and return empty but non nil values!

Answer 2

It seems to me that you want to use removingPercentEncoding to remove escape characters - those backslashes? While removingPercentEncoding is to work on percent encoded characters, e.g. to convert http%3A%2F%2Fwww.url-encode-decode.com%2F to http://www.url-encode-decode.com/. So you are using it at the wrong place. Make sure to call this method only on the URLs that are percent encoded.
For this scenario, like others already suggested, use JSONSerialization is the way to go.