I have created a screen with a text field called customer_number text field and another screen with a text field called password text field. I want to integrate my app with an existing API made by the backend developers. I am new to IOS Development and I don't know how to go about it. How do I make a get request and pass the login credentials for the user to login?
I want to get the customer number from the API and pass it to the app and enable the customer to log in.
I think this question is too big and complex to be replied exhaustively. You didn't tell us about the API. What kind of input does it take? What kind of response?
Supposing the simplest case. You API expects JSON objects as input and respond with another JSON object containing the information you request.
I usually do tasks like this using the NSURLRequest.
let js = ["Username":username, "Password":password]
let session = URLSession.init(configuration: .default)
let url = URL(...)
var req = URLRequest.init(url: url, cachePolicy: .reloadIgnoringLocalAndRemoteCacheData, timeoutInterval: 10)
req.httpMethod = "POST"
// Add some header key-value pairs
req.addValue(..., forHTTPHeaderField: ...)
...
let task = session.dataTask(with: request) { (data, response, error) in
guard error == nil else { return }
guard let responseData = data else { return }
let code = (response as! HTTPURLResponse).statusCode
// Checking for code == 200 states for authorised user. Generally log-in APIs should return some 4xx code if not allowed or non-authorised user.
if code == 200 {
// Now we try to convert returned data as a JSON object
do {
let json = try JSONSerialization.jsonObject(with: responseData, options: [])
// use your json object here, for example checking if contains the user number...
} catch {
// handle errors
}
}
}
task.resume()
I coded this very quickly, please check the correctness of al mechanism!
Related
When attempting an http request to my rest api, I continually get a 401 error when using the following code. I don not get this error making any other type of request. I have provided the function that makes the request below.
func deleteEvent(id: Int){
eventUrl.append(String(id))
let request = NSMutableURLRequest(url: NSURL(string: eventUrl)! as URL)
request.httpMethod = "DELETE"
print(eventUrl)
eventUrl.removeLast()
print(self.token!)
request.allHTTPHeaderFields = ["Authorization": "Token \(self.token)"]
let task = URLSession.shared.dataTask(with: request as URLRequest) { data, response, error in
if error != nil {
print("error=\(String(describing: error))")
//put variable that triggers error try again view here
return
}
print("response = \(String(describing: response))")
}
task.resume()
}
When sending the delete request with postman, the rest api just returns the data I want to delete but does not delete it. For reference I have posted the view and permissions classes associated with this request Any help understanding why this may be resulting in an error is greatly appreciated!
Views.py
class UserProfileFeedViewSet(viewsets.ModelViewSet):
"""Handles creating, reading and updating profile feed items"""
authentication_classes = (TokenAuthentication,)
serializer_class = serializers.ProfileFeedItemSerializer
queryset = models.ProfileFeedItem.objects.all()
permission_classes = (permissions.UpdateOwnStatus, IsAuthenticated)
def perform_create(self, serializer):
"""Sets the user profile to the logged in user"""
#
serializer.save(user_profile=self.request.user)
Permissions.py
class UpdateOwnStatus(permissions.BasePermission):
"""Allow users to update their own status"""
def has_object_permission(self, request, view, obj):
"""Check the user is trying to update their own status"""
if request.method in permissions.SAFE_METHODS:
return True
return obj.user_profile.id == request.user.id
HEADER SENT WITH DELETE REQUEST VIA POSTMAN
Preface: You leave out too much relevant information from the question for it to be properly answered. Your Swift code looks, and please don't be offended, a bit beginner-ish or as if it had been migrated from Objective-C without much experience.
I don't know why POSTMAN fails, but I see some red flags in the Swift code you might want to look into to figure out why your iOS app fails.
I first noticed that eventUrl seems to be a String property of the type that contains the deleteEvent function. You mutate it by appending the event id, construct a URL from it (weirdly, see below), then mutate it back again. While this in itself is not necessarily wrong, it might open the doors for racing conditions depending how your app works overall.
More importantly: Does your eventUrl end in a "/"? I assume your DELETE endpoint is of the form https://somedomain.com/some/path/<id>, right? Now if eventUrl just contains https://somedomain.com/some/path your code constructs https://somedomain.com/some/path<id>. The last dash is missing, which definitely throws your backend off (how I cannot say, as that depends how the path is resolved in your server app).
It's hard to say what else is going from from the iOS app, but other than this potential pitfall I'd really recommend using proper Swift types where possible. Here's a cleaned up version of your method, hopefully that helps you a bit when debugging:
func deleteEvent(id: Int) {
guard let baseUrl = URL(string: eventUrl), let token = token else {
// add more error handling code here and/or put a breakpoint here to inspect
print("Could not create proper eventUrl or token is nil!")
return
}
let deletionUrl = baseUrl.appendingPathComponent("\(id)")
print("Deletion URL with appended id: \(deletionUrl.absoluteString)")
var request = URLRequest(url: deletionUrl)
request.httpMethod = "DELETE"
print(token) // ensure this is correct
request.allHTTPHeaderFields = ["Authorization": "Token \(token)"]
let task = URLSession.shared.dataTask(with: request) { data, response, error in
if let error = error {
print("Encountered network error: \(error)")
return
}
if let httpResponse = response as? HTTPURLResponse {
// this is basically also debugging code
print("Endpoint responded with status: \(httpResponse.statusCode)")
print(" with headers:\n\(httpResponse.allHeaderFields)")
}
// Debug output of the data:
if let data = data {
let payloadAsSimpleString = String(data: data, encoding: .utf8) ?? "(can't parse payload)"
print("Response contains payload\n\(payloadAsSimpleString)")
}
}
task.resume()
}
This is obviously still limited in terms of error handling, etc., but a little more swifty and contains more console output that will hopefully be helpful.
The last important thing is that you have to ensure iOS does not simply block your request due to Apple Transport Security: Make sure your plist has the expected entries if needed (see also here for a quick intro).
Trying to figure this one out, I'm stumped. When making a REST call to get json data back from a response (GET or POST, each should return data) I get back 0 bytes.
This is pre-serialization. The POST successfully creates a message on the backend, and the backend shows a response being sent; with charles proxy on, I've confirmed that there is a response with valid JSON data.
Any ideas why this would be failing ONLY in iOS? Postman/Charles proxy (from the iOS calls!) shows valid data in the response, but the debugger picks up nothing.
Thanks in advance for anything thoughts.
let components = URLComponents(string: "mysuperValidURL.com")
guard let url = components?.url else {
return
}
var request = URLRequest(url: url)
request.httpMethod = "POST"
setUrlRequestToken(request: &request)
let message = ChatMessage(content: message, group: group, userId: userId)
let jsonEncoder = JSONEncoder()
guard let data = try? jsonEncoder.encode(message) else {
return
}
URLSession.shared.uploadTask(with: request, from: data) { (data, response, error) in
// Here there be 0 bytes
}.resume()
}
Data will sometimes come back as 0 bytes in the debugger; add a print with debug description to ensure you're getting data. In this case it was a failure of the debugger mixed with a later serialization error that caused it to appear to be broken.
TLDR; don't trust the realtime debugger, use some prints to sanity check.
Below is my code for HTTP request for getting and post. What I wanted to know is how to do HTTP request for delete and put. I have made it possible for get and post to work. I want to know how on the part of delete and put based on my code below. what to change in my postcode when I want to change it to delete? what is lacking? I wanted to delete using ID
like for example "id": 16,
let parameters = ["name": "test", "desc": "test" , "reward":"1.00" , "sched":"2018-04-05T11:49:51+08:00", "occurrence":["name": "once"]
, "status": "created", "created_by": "test#gmail.com","created_for": "test.com"] as [String : Any]
guard let url = URL(string: "http://test.tesst.eu:8000/api/v1/test/") else { return }
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
guard let httpBody = try? JSONSerialization.data(withJSONObject: parameters, options: []) else { return }
request.httpBody = httpBody
let session = URLSession.shared
session.dataTask(with: request) { (data, response, error) in
if let response = response {
print(response)
}
if let data = data {
do {
let json = try JSONSerialization.jsonObject(with: data, options: [])
print(json)
} catch {
print(error)
}
}
}.resume()
get
guard let url = URL(string: "http://test.test:8000/api/v1/test") else { return }
let session = URLSession.shared
session.dataTask(with: url) { (data, response, error) in
if let response = response {
print(response)
}
if let data = data {
print(data)
do {
let json = try JSONSerialization.jsonObject(with: data, options: [])
print(json)
} catch {
print(error)
}
}
}.resume()
The only one that differs is GET with the parameters are in the url itself , POST & DELETE & PUT are work the same way , just change the httpMethod parameter and specify httpBody if you wanted to , meaning
DELETE : means delete a resource from a specific url
PUT : place a resource in to a web server
//
let parameters = ["ID": "16"] as [String : Any]
guard let url = URL(string: "http://test.tesst.eu:8000/api/v1/test/") else { return }
var request = URLRequest(url: url)
request.httpMethod = "DELETE"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
guard let httpBody = try? JSONSerialization.data(withJSONObject:parameters, options: []) else { return }
request.httpBody = httpBody
You should go through difference between each method types. It will help you, what should you do and when.
PUT
Store an entity at a URI. PUT can create a new entity or update an existing one. A PUT request is idempotent. Idempotency is the main difference between the expectations of PUT versus a POST request.
The PUT method requests that the enclosed entity be stored under the supplied Request-URI. If the Request-URI refers to an already existing resource, the enclosed entity SHOULD be considered as a modified version of the one residing on the origin server. If the Request-URI does not point to an existing resource, and that URI is capable of being defined as a new resource by the requesting user agent, the origin server can create the resource with that URI. If a new resource is created, the origin server MUST inform the user agent via the 201 (Created) response. If an existing resource is modified, either the 200 (OK) or 204 (No Content) response codes SHOULD be sent to indicate successful completion of the request. If the resource could not be created or modified with the Request-URI, an appropriate error response SHOULD be given that reflects the nature of the problem. The recipient of the entity MUST NOT ignore any Content-* (e.g. Content-Range) headers that it does not understand or implement and MUST return a 501 (Not Implemented) response in such cases.
Modify the address with an ID of 1:
PUT /addresses/1
Note: PUT replaces an existing entity. If only a subset of data elements are provided, the rest will be replaced with empty or null.
urlRequestInstance.httpMethod = "PUT"
DELETE
Request that a resource be removed; however, the resource does not have to be removed immediately. It could be an asynchronous or long-running request.
The DELETE method requests that the origin server delete the resource identified by the Request-URI. This method MAY be overridden by human intervention (or other means) on the origin server. The client cannot be guaranteed that the operation has been carried out, even if the status code returned from the origin server indicates that the action has been completed successfully. However, the server SHOULD NOT indicate success unless, at the time the response is given, it intends to delete the resource or move it to an inaccessible location.
A successful response SHOULD be 200 (OK) if the response includes an entity describing the status, 202 (Accepted) if the action has not yet been enacted, or 204 (No Content) if the action has been enacted but the response does not include an entity.
Delete an address with an ID of 1:
DELETE /addresses/1
urlRequestInstance.httpMethod = "DELETE"
Here are nice tutorial references for you:
Understanding REST
REST Methods
What is the usefulness of PUT and DELETE HTTP request methods?
Now you can try a sample code, answered by Sh_Khan
How to translate my login user URLSession code into Siesta framework code? My current attempt isn't working.
I've looked at the example in the GithubBrowser but the API I have doesn't work like that.
The issue is that the user structure is kind of split by how the endpoint in the API I'm consuming works. The endpoint is http://server.com/api/key. Yes, it really is called key and not user or login. Its called that by the authors because you post a user/pass pair and get a key back. So it takes in (via post) a json struct like:
{"name": "bob", "password": "s3krit"}
and returns as a response:
{"token":"AEWasBDasd...AAsdga"}
I have a SessionUser struct:
struct SessionUser: Codable
{
let name: String
let password: String
let token: String
}
...which encapsulates the state (the "S" in REST) for the user. The trouble is name & password get posted and token is the response.
When this state changes I do my:
service.invalidateConfiguration() // So requests get config change
service.wipeResources() // Scrub all unauthenticated data
An instance is stored in a singleton, which is picked up by the configure block so that the token from the API is put in the header for all other API requests:
configure("**") {
// This block ^ is run AGAIN when the configuration is invalidated
// even if loadManifest is not called again.
if let haveToken = SessionManager.shared.currentUser?.token
{
$0.headers["Authorization"] = haveToken
}
}
That token injection part is already working well, by the way. Yay, Siesta!
URLSession version
This is bloated compared to Siesta, and I'm now not using this but here is what it used to be:
func login(user: SessionUser, endpoint: URL)
{
DDLogInfo("Logging in: \(user.name) with \(user.password)")
let json: [String: Any] = ["name": user.name, "password": user.password]
let jsonData = try? JSONSerialization.data(withJSONObject: json)
var request = URLRequest(url: endpoint)
request.httpMethod = "POST"
request.httpBody = jsonData
_currentStatus = .Unknown
weak var welf = self
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data else {
handleLogin(error: error, message: "No data from login attempt")
return
}
let jsonData:Any
do {
jsonData = try JSONSerialization.jsonObject(with: data, options: [])
}
catch let jsonDecodeError {
handleLogin(error: jsonDecodeError, message: "Could not get JSON from login response data")
return
}
guard let jsonDecoded = jsonData as? [String: Any] else {
handleLogin(error: error, message: "Could not decode JSON as dictionary")
return
}
guard let token = jsonDecoded["token"] as? String else {
handleLogin(error: error, message: "No auth token in login response")
return
}
let newUser = SessionUser(name: user.name, password: "", token: token)
welf?.currentUser = newUser
welf?.saveCurrentSession()
welf?._currentStatus = .LoggedIn
DDLogInfo("User \(newUser.name) logged in")
loginUpdate(user: newUser, status: .LoggedIn, message: nil, error: nil)
}
task.resume()
}
Siesta Version
Here is my attempt right now:
func login(user: String, pass: String, status: #escaping (String?) -> ())
{
let json = [ "name": user, "password": pass]
let req = ManifestCloud.shared.keys.request(.post, json: json)
req.onSuccess { (tokenInfo) in
if let token = tokenInfo.jsonDict["token"] as? String
{
let newUser = SessionUser(name: user, password: pass, token: token)
self.currentUser = newUser
}
status("success")
}
req.onFailure { (error) in
status(error.userMessage)
}
req.onCompletion { (response) in
status(nil)
}
}
Its sort of working, but the log in credentials are not saved by Siesta and I've had to rig up a new notification system for login state which I'd hoped Siesta would do for me.
I want to use Siesta's caching so that the SessionUser object is cached locally and I can use it to get a new token, if required, using the cached credentials. At the moment I have a jury-rigged system using UserDefaults.
Any help appreciated!
The basic problem here is that you are requesting but not loading the resource. Siesta draws a distinction between those two things: the first is essentially a fancied-up URLSession request; the second means that Siesta hangs on to some state and notifies observers about it.
Funny thing, I just answered a different but related question about this a few minutes ago! You might find that answer a helpful starting point.
In your case, the problem is here:
let req = ManifestCloud.shared.keys.request(.post, json: json)
That .request(…) means that only your request hooks (onSuccess etc.) receive a notification when your POST request finishes, and Siesta doesn’t keep the state around for others to observe.
You would normally accomplish that by using .load(); however, that creates a GET request and you need a POST. You probably want to promote your POST to be a full-fledge load request like this:
let keysResource = ManifestCloud.shared.keys
let req = keysResource.load(using:
keysResource.request(.post, json: json))
This will take whatever that POST request returns and make it the (observable) latestData of ManifestCloud.shared.keys, which should give you the “notification system for login state” that you’re looking for.
I am trying to pull my school grades from the website which stores all my grades, but I am having trouble logging in using HTTP requests, and pulling the information of the next page. Any help is appreciated :)
override func viewDidLoad() {
super.viewDidLoad()
let myUrl = NSURL(string: "https://homeaccess.katyisd.org/HomeAccess/Account/LogOn?ReturnUrl=%2fhomeaccess%2f")
let request = NSMutableURLRequest(URL: myUrl!)
request.HTTPMethod = "POST"
let postString = "User_Name=**hidden**&Password=**hidden**"
request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
let task = NSURLSession.sharedSession().dataTaskWithRequest(request){
data,response,error in
if(error != nil){
print("error=\(error)")
return
}
print("response = \(response)")
// Print out response body
let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
print("responseString = \(responseString)")
//Let’s convert response sent from a server side script to a NSDictionary object:
do{
var myJSON = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableLeaves) as? NSDictionary
if let parseJSON = myJSON {
// Now we can access value of First Name by its key
var firstNameValue = parseJSON["User_Name"] as? String
print("firstNameValue: \(firstNameValue)")
}
}catch{
print(error)
}
}
}
First, you need task.resume() after defining the task in order to start the connection loading, otherwise the object will be created and nothing will actually happen.
According to this error you posted, there's an SSL verification error on the site you are trying to access. The most secure option is to fix the SSL on the site, but I presume that is beyond your control in this case. The easier fix is to bypass the SSL error by adding "App Transport Security Settings" > "Allow Arbitrary Loads" = YES in your info.plist, as #André suggested. Or, if you are only using the one domain, bypass the particular domain in the NSExceptionDomains. See this question for more info.
According to this error you posted, a JSON parsing error is occurring. It is currently being caught and printed by your catch block, so the data is not actually processed. In your case, this is occurring because the response from Home Access Center is HTML, not JSON, so the JSON parser is failing. You are probably looking for an HTML parser. Swift does not have one built-in; look at this question for some example open-source options.
I have actually created a program that interfaces with Home Access Center. Sadly, there is no public API available -- APIs typically return JSON, which is easier to work with. Instead, you will need to use an HTML parser to analyze the page that is meant for human users and cookies to fake that a human user is logging on.
add task.resume() at the end of your code. also add the following to your info.plist file: