How to fix 'When converting from string to CLLocationCoordinate2D."

Question

I'm using decoder, And It will show me wrong answer, 1st line is a string, And the second one is I'm converting String to CLLocationCoordinate2D.

Why it makes 1st latitude and last longitude 0.0 ?

Question related to this is : Convert String of CLLocationCoordinate2D(s) into array

My requirement And I want output in this way and store it in let coordinates.

let coordinates = [
(-122.63748, 45.52214),
(-122.64855, 45.52218),
(-122.6545, 45.52219),
(-122.65497, 45.52196),
(-122.65631, 45.52104),
(-122.6578, 45.51935),
(-122.65867, 45.51848),
(-122.65872, 45.51293) ]

Encoding I'm encoding like this way, And encoding is 100% giving correct result.

 func encodeCoordinates(coords: [CLLocationCoordinate2D]) -> String {
//        let flattenedCoords: [String] = coords.map { coord -> String in "\(coord.latitude):\(coord.longitude)" }
        let flattenedCoords: [String] = coords.map { coord -> String in "\(coord.latitude):\(coord.longitude)"}
        let encodedString: String = flattenedCoords.joined(separator: ",")
        print("[\(encodedString)]")
        return encodedString
    }

It's Output is :

Error in decoding

I'm decoding in this way. I'm using this code, It's same like as Convert String of CLLocationCoordinate2D(s) into array But not giving me correct result.

func decodeCoordinates(encodedString: String) -> [CLLocationCoordinate2D] {
    let flattenedCoords: [String] = encodedString.components(separatedBy: ",")
    let coords: [CLLocationCoordinate2D] = flattenedCoords.map { coord -> CLLocationCoordinate2D in
        let split = coord.components(separatedBy: ":")
        if split.count == 2 {
            let latitude: Double = Double(split[0]) ?? 0.0
            let longitude: Double = Double(split[1]) ?? 0.0
            return CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
        } else {
            return CLLocationCoordinate2D()
        }
    }
    return coords
}

func makingRouteOfFreeRide(){

print("\n\n\n\n\n\n\n\n oooooo \(ProfileRoutesVC.map)\n\n\n\n\n\n\n\n\n",decodeCoordinates(encodedString: ProfileRoutesVC.map))
let a = decodeCoordinates(encodedString: ProfileRoutesVC.map)

You need to [edit] your question to include all relevant code in the form of a [mcve] in order to make it on-topic. Simply linking to another question won't make it on-topic. — Dávid Pásztor, Oct 17 '19 at 19:30

Ly Boung · Accepted Answer · 2019-10-18T06:33:49.823

1

In case your input string look like this:

let yourCoordinateString = "[32.4945:74.5229,32.4945:74.5229,32.4945:74.5229]"

func decodeCoordinates(encodedString: String) -> [CLLocationCoordinate2D] {
    var tmpString = encodedString
    tmpString.removeFirst(1)
    tmpString.removeLast(1)

    let flattenedCoords: [String] = tmpString.components(separatedBy: ",")
    let coords: [CLLocationCoordinate2D] = flattenedCoords.map { coord -> CLLocationCoordinate2D in
        let split = coord.components(separatedBy: ":")
        if split.count == 2 {
            let latitude: Double = Double(split[0]) ?? 0.0
            let longitude: Double = Double(split[1]) ?? 0.0
                return CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
            } else {
                return CLLocationCoordinate2D()
            }
        }

        return coords
}

edited Oct 18 '19 at 06:33

answered Oct 18 '19 at 05:20

Ly Boung

185
9

Sir, let coordinates = [ (-122.63748, 45.52214), (-122.64855, 45.52218), (-122.6545, 45.52219), (-122.65497, 45.52196), (-122.65631, 45.52104), (-122.6578, 45.51935), (-122.65867, 45.51848), (-122.65872, 45.51293) ] this is the Output I want – Engineer Muhammad Naeem Akram Oct 18 '19 at 05:27
**"32.4945:74.5229,32.4945:74.5229,32.4945:74.5229,32.4945:74.5229"** Assuming u have this string of coordinate right? – Ly Boung Oct 18 '19 at 05:32
Please try that input and just apply decode function – Engineer Muhammad Naeem Akram Oct 18 '19 at 05:36
Input: [My Input Code](https://drive.google.com/file/d/1tvs8pveGW2-UhMcDwZEU5kW75KzUJ14B/view?usp=sharing) Output: [My Output](https://drive.google.com/file/d/18vGc3jBDhtZWV7LLSISspcpSzEnLrqBW/view?usp=sharing) – Ly Boung Oct 18 '19 at 05:41
Actually this array is closed in Square Brackets. [32.4945:74.5229,32.4945:74.5229,32.4945:74.5229,32.4945:74.5229], So how to handle this ? – Engineer Muhammad Naeem Akram Oct 18 '19 at 05:43
Please see this. – Engineer Muhammad Naeem Akram Oct 18 '19 at 05:45
Do you mean the inputString? Like this? **"[32.4945:74.5229,32.4945:74.5229,32.4945:74.5229,32.4945:74.5229]"*** – Ly Boung Oct 18 '19 at 06:02
Yes Bro. [32.4945:74.5229,32.4945:74.5229,32.4945:74.5229,32.4945:74.5229] – Engineer Muhammad Naeem Akram Oct 18 '19 at 06:17
If that's the string that you input into your method, it's 100% wrong. Because of encodedString.components(separatedBy: ",") will split and the first element "[someCoorString" and when you put that into Double([someCoorString) it's gonna return nil. Same goes to the last element – Ly Boung Oct 18 '19 at 06:27
I've updated your `decodeCoordinates` method. check my above code again. That method will work in your case "[your coordinate string, your coordinate string]" – Ly Boung Oct 18 '19 at 06:35
I have a question, Is using encoder decoder is best or using this method ? – Engineer Muhammad Naeem Akram Oct 19 '19 at 06:42
It doesn't matter. We're just adapting to the response from API. Choose what make your code work ;) – Ly Boung Oct 19 '19 at 13:14

How to fix 'When converting from string to CLLocationCoordinate2D."

1 Answers1