Download PDF from API - swift

Question

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

Answer 1

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