iTunes_search_URLSession.swift

import Cocoa
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true


struct iTunesRequestManager {
    
    static func getSearchResult(_ query: String, results: Int, langString: String, completionHandler: @escaping ([[String: AnyObject]], NSError?) -> Void){
        var urlComponents = URLComponents.init(string: "https://itunes.apple.com/search")
        let termQueryItem = URLQueryItem.init(name: "term", value: query)
        let limitQueryItem = URLQueryItem.init(name: "limit", value: "\(results)")
        let mediaQueryItem = URLQueryItem.init(name: "media", value: "music")
        urlComponents?.queryItems = [termQueryItem, mediaQueryItem, limitQueryItem]
        
        guard let url = urlComponents?.url else {
            return
        }
        
        let task = URLSession.shared.dataTask(with: url) { (data, response, error) -> Void in
            guard let data = data else {
                completionHandler([], nil)
                return
            }
            do {
                guard let itunesData = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: AnyObject] else {
                    completionHandler([], nil)
                    return
                }
                if let results = itunesData["results"] as? [[String: AnyObject]] {
                    completionHandler(results, nil)
                } else {
                    completionHandler([], nil)
                }
            } catch _ {
                completionHandler([], error as NSError?)
            }
            
        }
        task.resume()
    }
}

iTunesRequestManager.getSearchResult("周杰伦", results: 2, langString: "zh_cn") { (result, error) in
    dump(result)
}