How to debug JSONDecoder when no errors show? - ios

Question

I'm building a Swift app and testing in an Xcode Playground. Calling the NYTimes Search API and trying to store its response in a struct. The code executes cleanly and no errors appear (I am using a do, try, catch), but I cannot print any properties from the resulting object (print(json.status)).
My hunch is that something is fishy with this line but I'm not sure what since no errors are printing from the catch statement
let task = URLSession.shared.dataTask(with: URL(string: url)!, completionHandler: { data, response, error in
Form the URL endpoint to make the API call:
func APICall() {
let APIKey = "MY_API_KEY_GOES_HERE_BUT_IT'S_A_SECRET"
let searchTerm = "A Super Bowl Sideshow: See the Ageless Man!"
// Remove the spaces and convert them to percents
guard let encodedSearchTerm = searchTerm.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)
else {
print("Error encoding search term in URL")
return
}
let url = "https://api.nytimes.com/svc/search/v2/articlesearch.json?q=" + encodedSearchTerm + "&api-key=" + APIKey
getData(from: url)
}
Data Task:
func getData(from url: String) {
//I believe something is wrong with the following line but I'm not sure what it is
let task = URLSession.shared.dataTask(with: URL(string: url)!, completionHandler: { data, response, error in
guard let data = data, error == nil else {
print("Error loading data")
return
}
var result: NYTSearchResponse?
do {
result = try JSONDecoder().decode(NYTSearchResponse.self, from: data)
} catch {
print(error)
}
guard let json = result else {
print("Error assigning result to json")
return
}
//Try to print these from the resulting object but these commands do not print
print(json.status)
print(json.response.docs[0].abstract)
})
task.resume()
}
My NYTSearchResponse struct which mirrors the NYT API JSON response. It's pretty complicated, but I pasted the json response into https://app.quicktype.io/ to build the struct.
// MARK: - Welcome
struct NYTSearchResponse: Codable {
let status, copyright: String
let response: Response
}
// MARK: - Response
struct Response: Codable {
let docs: [Doc]
let meta: Meta
}
// MARK: - Doc
struct Doc: Codable {
let abstract: String
let webURL: String
let snippet, leadParagraph, printSection, printPage: String
let source: String
let multimedia: [Multimedia]
let headline: Headline
let keywords: [Keyword]
let pubDate: Date
let documentType, newsDesk, sectionName, subsectionName: String
let byline: Byline
let typeOfMaterial, id: String
let wordCount: Int
let uri: String
enum CodingKeys: String, CodingKey {
case abstract
case webURL = "web_url"
case snippet
case leadParagraph = "lead_paragraph"
case printSection = "print_section"
case printPage = "print_page"
case source, multimedia, headline, keywords
case pubDate = "pub_date"
case documentType = "document_type"
case newsDesk = "news_desk"
case sectionName = "section_name"
case subsectionName = "subsection_name"
case byline
case typeOfMaterial = "type_of_material"
case id = "_id"
case wordCount = "word_count"
case uri
}
}
// MARK: - Byline
struct Byline: Codable {
let original: String
let person: [Person]
let organization: String?
}
// MARK: - Person
struct Person: Codable {
let firstname: String
let middlename: String?
let lastname: String
let qualifier, title: String?
let role, organization: String
let rank: Int
}
// MARK: - Headline
struct Headline: Codable {
let main: String
let kicker, contentKicker: String?
let printHeadline: String
let name, seo, sub: String?
enum CodingKeys: String, CodingKey {
case main, kicker
case contentKicker = "content_kicker"
case printHeadline = "print_headline"
case name, seo, sub
}
}
// MARK: - Keyword
struct Keyword: Codable {
let name, value: String
let rank: Int
let major: String
}
// MARK: - Multimedia
struct Multimedia: Codable {
let rank: Int
let subtype: String
let caption, credit: String?
let type, url: String
let height, width: Int
let legacy: Legacy
let subType, cropName: String
enum CodingKeys: String, CodingKey {
case rank, subtype, caption, credit, type, url, height, width, legacy, subType
case cropName = "crop_name"
}
}
// MARK: - Legacy
struct Legacy: Codable {
let xlarge: String?
let xlargewidth, xlargeheight: Int?
}
// MARK: - Meta
struct Meta: Codable {
let hits, offset, time: Int
}

Answer 1

I moved the code out of the playground and it works.