Bad Request: there is no photo in the request - api

Question

I'm trying to send an image from my application to telegram bot like here
https://newfivefour.com/swift-form-data-multipart-upload-URLRequest.html
Here is the code
let BotToken = "12345"
let ChatID = "123"
func SendToTelegram()
{
var request = URLRequest(url: URL(string: "https://api.telegram.org/bot"+BotToken+"/sendPhoto")!)
request.httpMethod = "POST"
let boundary = "Boundary-\(UUID().uuidString)"
request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
let params = [:] as [String: String]
UIGraphicsBeginImageContextWithOptions(ScreenImage.bounds.size, true, 0.0)
ScreenImage.image?.draw(in: CGRect(x: 0, y: 0, width: ScreenImage.frame.size.width, height: ScreenImage.frame.size.height))
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
request.httpBody = createBody(parameters: params,
boundary: boundary,
data: UIImageJPEGRepresentation(image!, 0.7)!,
mimeType: "image/jpg",
filename: "hello.jpg")
print(request.httpBody!)
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else { // check for fundamental networking error
return
}
do {
let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? AnyObject
if let parseJSON = json {
print("resp :\(parseJSON)")
}
} catch let error as NSError {
print("error : \(error)")
}
}
task.resume()
}
and get an error
Bad Request: there is no photo in the request";
"error_code" = 400;
ok = 0;
Where do i make a mistake? I'm new in SWIFT and sorry for my English

Answer 1

I know this question is old but the link provided pushed me in the right direction. This is my solution for server side Swift not iOS but you should be able to use it with minimal changes. Remember if you're using iOS, perform none of these operations on the main thread.
class NetworkManager {
func sendTelegramPhoto(_ photo: Data) {
let url = "https://api.telegram.org/bot\(Constants.Telegram.token)/sendPhoto"
let params: [String: Any] = [
"chat_id": Constants.Telegram.uid,
"photo": photo
]
let _ = sendMultiTypePostRequest(url, parameters: params)
}
private func sendMultiTypePostRequest(_ url: String, parameters: [String:String]) -> NetworkResponse {
var networkResponse = NetworkResponse()
let semaphore = DispatchSemaphore(value: 0)
guard let url = URL(string: url) else {
return networkResponse
}
var urlRequest = URLRequest(url: url)
urlRequest.httpMethod = "POST"
let boundary = "Boundary-\(UUID().uuidString)"
urlRequest.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
let httpBody = createBody(parameters: parameters,
boundary: boundary,
mimeType: "image/jpeg",
filename: "snapshot.jpg")
let config = URLSessionConfiguration.default
config.requestCachePolicy = .reloadIgnoringLocalCacheData
let session = URLSession(configuration: config)
let task = session.uploadTask(with: urlRequest, from: httpBody) { (data, response, error) in
networkResponse.data = data
networkResponse.response = response
networkResponse.error = error
semaphore.signal()
}
task.resume()
_ = semaphore.wait(timeout: .distantFuture)
return networkResponse
}
private func createBody(parameters: [String: String],
boundary: String,
mimeType: String,
filename: String) -> Data {
var body = Data()
let boundaryPrefix = "--\(boundary)\r\n"
for (key, value) in parameters {
if let data = value as? Data {
body.appendString(boundaryPrefix)
body.appendString("Content-Disposition: form-data; name=\"\(key)\"; filename=\"\(filename)\"\r\n")
body.appendString("Content-Type: \(mimeType)\r\n\r\n")
body.append(data)
body.appendString("\r\n")
} else if let string = value as? String {
body.appendString(boundaryPrefix)
body.appendString("Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n")
body.appendString("\(string)\r\n")
}
}
body.appendString("--".appending(boundary.appending("--")))
return body
}
}
private extension Data {
mutating func appendString(_ string: String) {
let data = string.data(using: String.Encoding.utf8, allowLossyConversion: false)
append(data!)
}
}