解析Wiki

Question

我是Swift的新手，我正在努力弄清楚如何解析附近的Wiki返回的JSON。在https://www.youtube.com/watch?v=sqo844saoC4的帮助下，我现在的处境如下：

import UIKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        let url = "https://en.wikipedia.org/w/api.php?action=query&list=geosearch&gscoord=37.7891838%7C-122.4033522&gsradius=10000&gslimit=2&format=json"
        getData(from: url)
        
        
    }
    
    private func getData(from url: String) {
        
        let task = URLSession.shared.dataTask(with: URL(string: url)!, completionHandler: {data, response, error in
            
            guard let data = data, error == nil else {
                print("Something went wrong")
                return
            }

            
            var result: Response?
            do {
                result = try JSONDecoder().decode(Response.self, from: data)
            }
            catch {
                print("failed to convert \(error.localizedDescription) ")
            }
            
            guard let json = result else {
                return
            }
            
            print(type(of: json.query.geosearch))
            print(json.query.geosearch.self)
            
            
        })
        task.resume()
    }
    
    
}



struct Response: Codable {
    let batchcomplete: String
    let query: Query
}

struct Query: Codable {
    let geosearch: [Geosearch]?
}

struct Geosearch: Codable {
    
    let pageid: Int?
    let title: String?
}

遵循Need help parsing wikipedia json api in SWIFT，我相信地理搜索是一本字典。代码运行，但是如何从地理搜索检索标题或页面(打印(json.query.geosearch.title)给出一个错误)？

抱歉-可能是一些很基本的东西.如有任何指示，将不胜感激。

菲利普

Answer 1

试试下面的代码。它使用一个完成闭包来“等待”，直到在返回结果之前获取结果。因为geosearch是一个数组，所以您需要遍历它。注意，分析json响应时没有出现错误。为我工作。

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        let url = "https://en.wikipedia.org/w/api.php?action=query&list=geosearch&gscoord=37.7891838%7C-122.4033522&gsradius=10000&gslimit=2&format=json"
        
        getData(from: url) { response in
            if let result = response,
               let geosearch = result.query.geosearch {
                print("-----> result: \(result) \n")
                for geo in geosearch {
                    print("geo.title: \(geo.title)")
                }
            }
        }
    }
    
   func getData(from url: String, completion: @escaping(Response?) -> ()) {
    if let theURL = URL(string: url) {
        let task = URLSession.shared.dataTask(with: theURL) { data, response, error in
            guard let data = data, error == nil else {
                print("Something went wrong")
                completion(nil)
                return
            }
            do {
                let result = try JSONDecoder().decode(Response.self, from: data)
                completion(result)
            } catch {
                print("failed to convert \(error) ")
                completion(nil)
            }
        }
        task.resume()
    }
}
    
}

Answer 2

您需要访问数组项才能获得页面或标题，如下所示：

print(json.query.geosearch?[0].title ?? "")

因为json返回一个数组

{
  "batchcomplete": "",
  "query": {
    "geosearch": [
      {
        "pageid": 18618509,
        "ns": 0,
        "title": "Wikimedia Foundation",
        "lat": 37.78916666666667,
        "lon": -122.40333333333334,
        "dist": 2.5,
        "primary": ""
      },
      {
        "pageid": 42936625,
        "ns": 0,
        "title": "Foxcroft Building",
        "lat": 37.78916666666667,
        "lon": -122.40333333333334,
        "dist": 2.5,
        "primary": ""
      }
    ]
  }
}

Answer 3

print(json.query.geosearch.self) //This will store the repsone in the let geosearch: [Geosearch]?


//You can check the individual result for the 1st and 2nd object 
print(json.query.geosearch[0].pageid)//18618509
print(json.query.geosearch[0].title) //"Wikimedia Foundation"

print(json.query.geosearch[1].pageid)//42936625
print(json.query.geosearch[1].title) //"Foxcroft Building"