The API I am using has 3 parameters year month and salaryType.

When I enter those parameters to my URL

if let url = URL(string: "https://rip.rtuk.gov.tr/workplacebackend/api/Employee/GetPayroll?yil=\(year)&ay=\(month)&maasturu=\(salaryType)")

URL becomes

"https://rip.rtuk.gov.tr/workplacebackend/api/Employee/GetPayroll?yil=2020&ay=2&maasturu=1"

When I enter this URL with Auth and Token it returns a pdf file. How should I modify my getPayroll so that I can download pdf after the request?

 func getPayroll(year: Int, month: Int, salaryType: Int, completion: @escaping (String) -> ()) {
    if let url = URL(string: "https://rip.rtuk.gov.tr/workplacebackend/api/Employee/GetPayroll?yil=\(year)&ay=\(month)&maasturu=\(salaryType)") {
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        request.addValue("Basic \(authToken)", forHTTPHeaderField: "Authorization")
        request.addValue(workingToken, forHTTPHeaderField: "token")
        let task = URLSession.shared.downloadTask(with: request) { (localURL, urlResponse, error) in
            if let localURL = localURL {
                if let string = try? String(contentsOf: localURL) {
                    completion(string)
                }
            }
        }
        task.resume()
    }
}

So when I tap on a cell I want to show an alert, download and then open pdf

 func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    switch cellType(rawValue: selected.title) {
    case .salary:
        selectedPayment = (payment?[indexPath.row])!
        RtukNetworkManager.shared.getPayroll(year: selectedPayment.year, month: selectedPayment.month, salaryType: selectedPayment.paymentType) { filePath in
             DispatchQueue.main.async {
                self.displayDownloadAlert(filePath)
            }
        }

 func downloadFile(path: String) {
    let donwloadManager = FileDownloadManager()
    donwloadManager.downloadFile(path: path, viewController: self)
}

When I tap on a cell getting an error as an alert

Error The document can not be shown

CodePudding user response：

this will save pdf file to url and also check if already downloaded

func getPayroll(year: Int, month: Int, salaryType: Int, completion: @escaping ((URL?) -> ())) {
            let documentsUrl =  FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
            
            let parameters: [String: Int] = ["yıl": year, "ay": month, "maasturru": salaryType]
            if let url = URL(string: "https://rip.rtuk.gov.tr/workplacebackend/api/Employee/GetPayroll?yil=\(year)&ay=\(month)&maasturu=\(salaryType)") {
                
                let destinationUrl = documentsUrl.appendingPathComponent(url.lastPathComponent)
                if FileManager().fileExists(atPath: destinationUrl.path) {
                    print("File already exists [\(destinationUrl.path)]")
                    completion(destinationUrl)
                }
                var request = URLRequest(url: url)
                request.httpMethod = "GET"
                request.addValue("Basic \(authToken)", forHTTPHeaderField: "Authorization")
                request.addValue(workingToken, forHTTPHeaderField: "token")
                let session = URLSession(configuration: .default)
                let task = session.dataTask(with: request) { (data, response, error) in
                    if error == nil {
                        if let response = response as? HTTPURLResponse  {
                            if response.statusCode == 200 {
                                if let data = data  {
                                    if let _ = try? data.write(to: destinationUrl, options: Data.WritingOptions.atomic)
                                    {
                                        completion(destinationUrl)
                                    }
                                    else
                                    {
                                        completion(destinationUrl)
                                    }
                                }
                            }
                        }
                    } else {
                        print(error?.localizedDescription)
                        completion(nil)
                    }
                }
                task.resume()
            }
        }

after that call your to download

RtukNetworkManager.shared.getPayroll(year: selectedPayment.year, month: selectedPayment.month, salaryType: selectedPayment.paymentType) { filePath in  
     if let url = filePath {
       self.displayDownloadAlert(url.lastPathComponent)
       showPdf(url:url)
     }
            
  }

to show pdf

 func showPdf(url:URL) {
                let pdfView = PDFView(frame: CGRect(x:100,y:100,width:200,height:200))
                let pdfDocument = PDFDocument(url: url)) 
     
                pdfView.autoresizesSubviews = true
                pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight, .flexibleTopMargin, .flexibleLeftMargin]
                pdfView.displayDirection = .vertical
                pdfView.autoScales = true
                pdfView.displayMode =  .singlePage 
                pdfView.displaysPageBreaks = true
                pdfView.document = pdfDocument
                pdfView.maxScaleFactor = 4.0
                pdfView.minScaleFactor =     pdfView.scaleFactorForSizeToFit
                pdfView.usePageViewController(true, withViewOptions: [:])
               view.addSubview(pdfView)

  }

also import PDFKit PDFView use for displaying pdf