I am trying to perform an HTTP POST request in swift that will send some data to my server using PHP file, but it crashes with the error
Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value
The token and selectedAreaNames (the error is in the first line) are just regular strings. What could be the problem?
let url = URL(string: "https://xxxxxxx.xxx/register.php/\(token)|\ (selectedAreaNames)")! //error is here...
var request = URLRequest(url: url)
request.httpMethod = "POST"
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
if let error = error {
print("error: \(error)")
} else {
if let response = response as? HTTPURLResponse {
print("statusCode: \(response.statusCode)")
}
if let data = data, let dataString = String(data: data, encoding: .utf8) {
print("data: \(dataString)")
}
}
}
task.resume()
Assuming that’s really how your URL must look, you can do:
let url = URL(string: "https://xxxxxxx.xxx/register.php")!
.appendingPathComponent(token + "|" + selectedAreasNames)
That will percent escape those portions of the URL (including the |).
That having been said, this is an exceedingly unusual format for a POST request, which usually has the data being posted inside the body of the request, not just added as another path component of the URL. And if this was a GET request, where the parameters are added to the URL, you’d generally see this after a ? in the URL, separating the path of the request from the query. And this structure of simply TOKEN|VALUES is an unusual query structure, too.
Related
I'm beginner in SwiftUI and I'm not familiar with variable management.
I'd like to send a very simple post request like this one with SwiftUI:
let full_path : String = "https://www.example.com/get_answer?my_message=current temperature"
I've tried with this piece of code but it didn't work.
if (URL(string: full_path) != nil) {
let url = URL(string: full_path)!
var request = URLRequest(url: url)
request.httpMethod = "POST"
var decodedAnswer = String("")
do {
let task = URLSession.shared.dataTask(with: url) { data, response, error in
print(response)
decodedAnswer = String(decoding: response, as: UTF8.self)
}
}
I have the following error:
Value of optional type 'URLResponse?' must be unwrapped to a value of
type 'URLResponse'
I don't know how to get the response.
How can I get the response from a simple Post request in SwiftUI?
Multiple issues here.
You are trying to decode the URLResponse object, but what you want is the data object in the decoder.
You seem to not know about optionals. I would refer you to the basic Apple tutorials about this topic. You can find it with your favorite search engine.
You are in an async context here. Everything inside the url datasession closure will be execute after your network request returns. The code in your function will be completed by that moment and your var decodedAnswer will be out of scope. So move it out of the function in to the class/struct.
You probably want something like this:
This should be defined in class scope or you won´t be able to use it:
var decodedAnswer: String = ""
This should be in a function:
let full_path: String = "https://www.example.com/get_answer?my_message=current temperature"
if let url = URL(string: full_path) {
var request = URLRequest(url: url)
request.httpMethod = "POST"
do {
let task = URLSession.shared.dataTask(with: url) { data, response, error in
//This converts the optionals in to non optionals that could be used further on
//Be aware this will just return when something goes wrong
guard let data = data, let response = response, error == nil else{
print("Something went wrong: error: \(error?.localizedDescription ?? "unkown error")")
return
}
print(response)
decodedAnswer = String(decoding: data, as: UTF8.self)
}
task.resume()
}
}
I am using an online swift playground to test http post and get request, the post aspect works fine, but when i add the get request,it gives the following error"error: extraneous '}' at top level.
The post code works fine.
// Post method
var url = URL(string: "http://196.46.20.80:8085/fideldesign")!
var request = URLRequest(url: url)
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
let postString = "email=oshinowo_sola#yahoo.ca&amount=15000&description=swift¤cy=566&fee=0&returnurl=http://www.oleronesoftwares.com&secretkey=2BC80A5EB5BB6A64A772F9806A7E9A0B16702043AB475DC4" // which is your parameters
request.httpBody = postString.data(using: .utf8)
//Getting response for POST Method
DispatchQueue.main.async {
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
return // check for fundamental networking error
}
// Getting values from JSON Response
let responseString = String(data: data, encoding: .utf8)
print("responseString = \(String(describing: responseString))")
do {
let jsonResponse = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions()) as? NSDictionary
}catch _ {
print ("OOps not good JSON formatted response")
}
}
task.resume()
}
The code is to post dynamic records from user input like email address,amount,description into an external url and then return the get request in json format.
Try closing the project and opening it again.
I was getting this same error and also when I tried pressing Enter (typing newline character) on the line that was problematic (It was the last line in the file for me), Xcode would insert the characters
ker;")
into my editor.
I was getting this error, until I closed and reopened the project, in which these errors went away and the random characters stopped appearing also.
What worked for me was replacing the file.
Create new file, different name than current buggy file.
Copy/paste code into this new file.
Go ahead and delete that file with the error.
..For some reason using the same name transferred over the error, even if I deleted the other file.
My question is simple: how do you call a HTTP GET Request in Swift?
I am trying to retrieve specific data from server (I have the URL string), the problem is that the previous answers I saw, doesn't explain thoroughly how to request an HTTP Get and save the retrieved information in a variable to be used later? Thanks in advance!
Here's what I have so far:
let myURL = NSURL(string:"https://api.thingspeak.com/channels/CHANNEL_ID/last_entry
_id.txt");
let request = NSMutableURLRequest(url:myURL! as URL);
request.httpMethod = "GET"
Not sure what do following requesting the GET.
In your post you are missing the part that does the actual getting to of the data.
Your code should look something like this to get the value out of the text file.
var lastID: String?
let myURL = NSURL(string:"https://api.thingspeak.com/channels/1417/last_entry_id.txt");
let request = NSMutableURLRequest(url:myURL! as URL);
//request.httpMethod = "GET" // This line is not need
// Excute HTTP Request
let task = URLSession.shared.dataTask(with: request as URLRequest) {
data, response, error in
// Check for error
if error != nil
{
print("error=\(error)")
return
}
// Print out response string
let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
print("responseString = \(responseString!)")
lastID = "\(responseString!)" // Sets some variable or text field. Not that its unwrapped because its an optional.
}
task.resume()
I'm trying to do a PUT request using Swift. In a REST client, when I try to do a REST request the following way:
In Body- x-www-form-urlencoded, I add vote=1 and with id being taken in the param for example: /user/:id, it works!
I try to do the same in Swift code, it does not work and I get responseString = Optional(502 Bad Gateway: Registered endpoint failed to handle the request.
Here is my code:
var baseURL = "http://<domain>/user"
let putURL = baseURL + "/\(id)"
print(putURL)
let request = NSMutableURLRequest(URL: NSURL(string: putURL)!)
request.HTTPMethod = "PUT"
let putString = "vote=1"
request.HTTPBody = putString.dataUsingEncoding(NSUTF8StringEncoding)
request.timeoutInterval = 1500
let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
data, response, error in
guard error == nil && data != nil else {
print("error=\(error)")
return
}
let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
print("responseString = \(responseString)")
}
task.resume()
You forgot to set the content type, e.g.
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
Without that, the server won't know what to do with the blob of random data that you just sent it.
I'm not saying that this is necessarily the only problem, but it is definitely a problem, and one big enough to cause the error you're seeing.
My url Request is like "http://www.heriam.com/gms.setvalue%20dim100%"
and i use Alamofire for the Request
Tha APP chrashed with fatal error: unexpextendly found nil while unwrapping an Optional Value
Alamofire.request(.GET, "http://www.heriam.com/gms.setvalue%20dim100%")
.authenticate(usingCredential: credential)
.response {(request, response,string, error) in
println(response)
}
The problem is the last %! If i leave it all is fine an the Request works.
do you have an idea sending a Request ending with an %???
You have to prepare your link before converting it to url using stringByAddingPercentEscapesUsingEncoding. Besides that NSURL method might return nil so you should use if let to unwrap the optional result as follow:
let link = "http://www.heriam.com/gms.setvalue%20dim100%"
if let linkWithPercentEscape = link.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding) {
if let url = NSURL(string: linkWithPercentEscape) {
println(url)
}
}