Is there any way in Swift to find out if data from a request returns in gzip?
I want to write a test method to check if Content-Encoding returns gzip file:
You can get this info from the header fields in the HTTPURLResponse:
URLSession.shared.dataTask(with: url) { (data, response, error) in
if let response = response as? HTTPURLResponse {
if let encoding = response.allHeaderFields["Content-Encoding"] as? String {
print(encoding)
print(encoding == "gzip")
}
}
}.resume()
Note that this downloads the headers and the data.
If you want to only get the headers without downloading the data, a better solution is to use an URLRequest set to "HEAD" like this:
var request = URLRequest(url: url)
request.httpMethod = "HEAD"
URLSession.shared.dataTask(with: request) { (_, response, _) in
if let response = response as? HTTPURLResponse {
if let enc = response.allHeaderFields["Content-Encoding"] as? String {
print(enc)
print(enc == "gzip")
}
}
}.resume()
This way, only the headers are downloaded.
If you read the first 4 bytes of the file, you should get a Magic Number
So you should be able to do something like:
var magicNumber = [UInt](count: 4, repeatedValue: 0)
data.getBytes(&magicNumber, length: 4 * sizeof(UInt))
If it's GZipped, it will have a Magic Number of 1f 8b, so check for that.
Related
I am using a asp.net back end with a login end point but no matter what I DO in the swift version of this code I get a 415 when I use it in .net and sharp the api works am not sure what am doing wrong here.
And yes I have enabled transport protocol but its not decoding the jwt token correctly for me in swift
Basically the end point returns the jet token used for accessing the api in an object
let jwtAccessToken: String = ""
let urlString = "http://url.com/login" *** hidden for security
purposes but is correct ****
func CallWebApi()
{
// create the url with URL
let url = URL(string: urlString)! // change server url accordingly
let parameters: [String: Any] = [ "username":
"user1#domain.com", "password": "pass1"]
var request = URLRequest(url: url)
request.setValue("application/x-www-form-urlencoded",
forHTTPHeaderField: "Content-Type")
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpMethod = "Post"
do {
request.httpBody = try
JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
} catch let error {
print(error.localizedDescription)
return
}
let task = URLSession.shared.dataTask(with: request) {
data, response, error in
guard
let data = data,
let response = response as? HTTPURLResponse,
error == nil
else {
// check for fundamental networking error
print("error", error ?? URLError(.badServerResponse))
return
}
guard (200 ... 299) ~= response.statusCode else {
// check for http errors
print("statusCode should be 2xx, but is \(response.statusCode)")
print("response = \(response)")
return
}
// do whatever you want with the `data`, e.g.:
do {
let responseObject = data
print(responseObject)
} catch {
print(error)
// parsing error
if let responseString = String(data: data, encoding: .utf8) {
print("responseString = \(responseString)")
} else {
print("unable to parse response as string")
}
}
}
task.resume()
}
MyModel is basically a string
import Foundation
class AuthenticationResponse: ObservableObject {
#Published var jwtToken: String
init(jwtToken: String) {
self.jwtToken = jwtToken
}
}
I think 20 years of c sharp in not helping and am doing things it way and not the swift way if someone could advice be great.
Also in csharp we were told its not great in keeping alive the http client as can degrade performance is this the same for swift and if any library's you can recommend makes the code a bit neater the api has swagger docs enabled.
Edit 3
Example response expected back
{
"id": "b181104e-ba3e-4dba-b124-4bb4a3873b17",
"firstName": "user1",
"lastName": "lastname",
"username": "user1lastname#domainname.com",
"playerId": 0,
"jwtToken": "token in is here",//hidden for security
"error": {
"eventName": null,
"errorMessage": null,
"errorDate": null,
"statusCode": null,
"json": null
},
"refreshToken": null
}
I typically send this to the end point from C sharp
{
"username": "user1#domain.com",
"password": "pass1"
}
What I found I had to do was this
let decoder = JSONDecoder()
let responseObject = try
decoder.decode(AuthenticationResponse.self, from: data)
print(responseObject)
And change my class to be off this
import Foundation
struct AuthenticationResponse: Codable {
var jwtToken: String
}
After I done that I got the expected string back but my question is how does one get this to run correctly its completing before I think I need await but also where is it best to stored the jwttoken?
A POST http request:
task.request = sessionManager?.request(url!, method: method, parameters: paramters, encoding: JSONEncoding.prettyPrinted, headers: nil).responseJSON { response in
task.handleResponse(response: response)
}
The response is a JSON string like this:
{\"Data\":{\"ArrayOfItems\":[{\"ActualQty\":\"5.0\",\"BatchManaged\":true,\"ArrayOfBatches\":[{\"BatchNumber\":1,\"Counted\":\"ADD\", \"Quantity\":10},{\"BatchNumber\":2,\"Counted\":\"ADD\", \"Quantity\":10}],\"LineNum\":\"1\",\"ItemCode\":\"M1001-L\",\"WarehouseCode\":\"Store\"}],\"Comments\":\"Ht\",\"DocEntry\":\"1\",\"Quantiry\":\"123\",\"Initials\":\"RT\"},\"PromptAnswerValue\":[]}
The Alamofire can not parse the response JSON string. Errors is flonwing:
responseSerializationFailed(reason: Alamofire.AFError.ResponseSerializationFailureReason.jsonSerializationFailed(error: Error Domain=NSCocoaErrorDomain Code=3840 "No string key for value in object around character 40." UserInfo={NSDebugDescription=No string key for value in object around character 40.}))
Debuged, the failed in 'let json = try JSONSerialization.jsonObject(with: validData, options: options)' line. See attached file flowing:
The validData is valuable. Why is this happening?
I write a demo and I can receving the response json string, the code like this:
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.setValue("\(jsonData.length)", forHTTPHeaderField: "Content-Length")
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpBody = jsonData as Data
let session = URLSession.shared
let task = session.dataTask(with: request as URLRequest) {(
data, response, error) in
guard let data = data, let _:URLResponse = response, error == nil else {
print("error")
return
}
let dataString = String(data: data, encoding: String.Encoding.utf8)
let dict = self.getDictionaryFromJSONString(jsonString: dataString!)
print(dict)
}
task.resume()
Used the URLSession can do this, but why the Alamofire can not? Is it the problem I use? Please advise.
Thanks.
The issues I had solved. This is caused by the invalid JSON string in response.
Debug as flowing:
Debug here and do this in the console
po String(data: validData, encoding: String.Encoding.utf8)
Check if the JSON string is valid.
Besides, note: Use JSONEncoding.prettyPrinted.
I don't feel like sharing the actual link as it may have some private information so don't be surprised if it doesn't work.
I have a link that looks like this: www.somelink.com/stuff/searchmembers?member=John
And some headers that I need to pass, like Login: Admin, Password: Admin
When I use this site everything seems to be working just fine, I put the link, make it GET and put headers in key:value format and as a result I get the list of all members, but how can I do the same with URLSession? Here's what I currently have and I don't get anything at all. What am I doing wrong there?
func getAllMembers(urlString: String) {
guard let url = URL(string: urlString) else { return }
var request = URLRequest(url: url)
request.httpMethod = "GET"
request.setValue("Admin", forHTTPHeaderField: "Login")
request.setValue("Admin", forHTTPHeaderField: "Password")
request.httpBody = "member=John".data(using: .utf8)!
URLSession.shared.dataTask(with: request) { (data, response, error) in
print(response)
print(data)
}.resume()
}
Here is What You're Doing Wrong:
Your member=John is actually a URL query parameter. In general, URL requests have query parameters as a part of the URL string itself and not the httpbody.
Quick and Dirty Solution:
You should be good to go if you remove
request.httpBody = "member=John".data(using: .utf8)!
and instead pass the whole "www.somelink.com/stuff/searchmembers?member=John" into your getAllMembers(urlString:) function.
A Better Solution:
Let's say John's username is j o h n. Your function wouldn't make it past that first guard because spaces aren't valid URL string characters.
I like to use URLComponents because it saves me the trouble of having to handle spaces and such.
Here's how I'd write your function:
func getJohnMember(urlString: String) {
//URLComponents to the rescue!
var urlBuilder = URLComponents(string: urlString)
urlBuilder?.queryItems = [
URLQueryItem(name: "member", value: "j o h n")
]
guard let url = urlBuilder?.url else { return }
var request = URLRequest(url: url)
request.httpMethod = "GET"
request.setValue("Admin", forHTTPHeaderField: "Login")
request.setValue("Admin", forHTTPHeaderField: "Password")
URLSession.shared.dataTask(with: request) { (data, response, error) in
print(response)
print(String(data: data, encoding: .utf8)) //Try this too!
}.resume()
}
Just to be clear, I would pass just "www.somelink.com/stuff/searchmembers" into the first parameter.
Now if I were to print(url) after the guard let, I'd get
www.somelink.com/stuff/searchmembers?member=j%20o%20h%20n
Much easier this way, no?
That member=John is a URL-query parameter, not part of the request body. So you need to add it to the URL itself.
func getAllMembers(urlString: String) {
guard let url = URL(string: "\(urlString)?member=John") else { return }
var request = URLRequest(url: url)
request.httpMethod = "GET"
request.setValue("Admin", forHTTPHeaderField: "Login")
request.setValue("Admin", forHTTPHeaderField: "Password")
URLSession.shared.dataTask(with: request) { (data, response, error) in
print(response)
print(data)
}.resume()
}
I can easily issue a GET request and it returns (as expected) JSON data that is decoded to myDataModel object:
class func getData(completionHandler: #escaping (myDataModel?, Error?) -> Void)
{
let url = "https://example.com/api/someResource?ws_key=ABC...XYZ"
if let myUrl = URL(string: url)
{
URLSession.shared.dataTask(with: myUrl)
{
(data, response, err) in
if let data = data
{
do
{
let result = try JSONDecoder().decode(myDataModel.self, from: data)
completionHandler(result, nil)
}
catch let JSONerr
{
completionHandler(nil, JSONerr)
}
}
}.resume()
}
}
This work fine, so GET is no problem. (PS. the above has been simplified and modified.)
Likewise, I can issue a POST request and it returns (as expected) JSON data, when I use parameters like key1=value1&key2=value2. (I read that the default POST Content-Type is application/x-www-form-urlencoded.)
However, in another application I need to POST a piece of XML. After many tries and getting many errors, the approach I'm using is to: Set the header Content-Type to text/xml; charset=utf-8; Have no parameters and send the XML as the request body. I use a refined method:
PostHTTP(url: "https://example.com/api/someResource?ws_key=ABC...XYZ",
parameters: nil,
headers: ["Content-Type": "text/xml; charset=utf-8", "Content-Length": "\(xml.count)"],
body: "\(xml)") { (result) in ... }
(I image that you can determine what happens behind the scenes.)
For the POST request, to send a piece of XML:
Do I need to set the Content-Length or is this automatic?
Can I send parameters with the XML?
What headers (like Content-Type) do I require?
What structure (eg. xml=<?xml...) and encoding (eg. addingPercentEncoding) do I require?
Also I need to PUT data and I have similar method. The response from my attempt has the error
String could not be parsed as XML, XML length: 0
For a PUT request:
What headers (like Content-Type) do I require?
What structure (eg. xml=<?xml...) and encoding (eg. addingPercentEncoding) do I require?
Since I have tried many ways, an example of both PUT and POST would be ideal.
If you want to send data of XML you can do this in both PUT and POST
It does not have to be determined Content-Length
But you must add Content-Type
let req = NSMutableURLRequest(url: URL(string:"myUrl")!)
req.httpMethod = "POST"
req.setValue("application/xml;charset=utf-8;", forHTTPHeaderField: "Content-Type")
req.setValue("application/xml;", forHTTPHeaderField: "Accept")
var postBody = Data()
if let anEncoding = ("<?xml version='1.0' encoding='UTF-8'?>").data(using: .utf8) {
postBody.append(anEncoding)
}
if let anEncoding = "<Request>".data(using: .utf8) {
postBody.append(anEncoding)
}
if let anEncoding = "<test>\(123)</test>".data(using: .utf8) {
postBody.append(anEncoding)
}
if let anEncoding = "</Request>".data(using: .utf8) {
postBody.append(anEncoding)
}
req.httpBody = postBody
req.setValue("\(postBody.count)", forHTTPHeaderField: "Content-Length")
URLSession.shared.dataTask(with: req as URLRequest) { (data, urlreq, error) in
}
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()