I'd like to make multiple POST requests to a web server that I have got which inserts a new record in a table in my database. This will be repeated depending on the amount of exercises the user inputs.
I have a function for the POST request which is as follows.
func submitDetails(split_id:Int, day:String, name:String, set:String, rep:String)
{
var request = URLRequest(url: URL(string: "LINK OF WEB SERVICE")! as URL)
request.httpMethod = "POST"
let postString = "id=\(split_id)&day=\(day)&name=\(name)&sets=\(set)&reps=\(rep)"
print("Post string - \(postString)")
request.httpBody = postString.data(using: String.Encoding.utf8)
let task = URLSession.shared.dataTask(with: request as URLRequest)
{
data, response, error in
if error != nil
{
print("error=\(String(describing: error))")
return
}
print("response = \(String(describing: response))")
let responseString = String(data: data!, encoding: String.Encoding(rawValue: String.Encoding.utf8.rawValue))
print ("responseString =\(String(describing: responseString))")
}
task.resume()
}
This is called within a loop,
for x in 0...MainMenuViewController.myVariables.day1NoExercise - 1
{
self.submitDetails(split_id: MainMenuViewController.myVariables.new_split_id, day: self.dayName.text!, name: self.exerciseName[x].text!, set: self.exerciseSets[x].text!, rep: self.exerciseReps[x].text!)
}
Currently, only the first exercise that the user inputs data for is inserted into the database. It seems like it is executing all the code too fast. I hope someone understands this and can help me out!
for API Calls always run asynchronous request
use background thread to help your application remain responsive
use compilation block to display error
show progress bar or something like that to let the user know that you are doing something
add Extra function to your server to allow bulk posting "Reduce http sessions "
Read :
https://medium.com/#sdrzn/networking-and-persistence-with-json-in-swift-4-c400ecab402d
https://medium.com/#sdrzn/networking-and-persistence-with-json-in-swift-4-part-2-e4f35a606141
Advise :
it's look like you taking your first steps with Swift/IOS so Just use http library like Alamofire to avoid all headache Like Queuing,Threading,Complitions Block .
https://github.com/Alamofire/Alamofire
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).
My iOS application allows a user to submit a complaint to an online REST API with the following parameters:
Data Fields: such as name, phone number, ...
Voice: recorded from microphone
Image/Video: selected from photo gallery
1- how can i do that with swift?
2- how to get back an ID field from the server after submission?
3- how to manage an upload progress for the voice and media files?
Regards
After few weeks working hardly on it, here is my experience using Swift 3.1 which is run smoothly:
//use POSTMAN plugin in Chrome browser to get the read header for your API (optional):
let headers = [
"cache-control": "no-cache",
"postman-token": "00000000-1111-2222-3333-444444444"]
//this is the important part:
let strQuery: String = "mobileNo=" + txtMobileNB.text! + "&fullname=" + txtName.text!
let request = try? NSMutableURLRequest(url: NSURL(string: "http://service.website.com/apiname/?" + strQuery)! as URL,
cachePolicy: .useProtocolCachePolicy,
timeoutInterval: 10.0)
request?.httpMethod = "POST"
request?.allHTTPHeaderFields = headers
if request != nil {
let session = URLSession.shared
let dataTask = session.dataTask(with: request! as URLRequest) {data,response,error in
if let content = data
{
let responseData = String(data: content, encoding: String.Encoding.utf8)
//feedback from server:
print(responseData)
//call success function:
self.showDone()
} else {
//call error function:
self.showWrong()
}
}
dataTask.resume()
} else {
//call error function:
self.showWrong()
}
Regarding the other part "how to upload", i've found this framework is a good one (called rebekka) to start your upload project through iOS apps.
hope this helps someone :)
I've been trying to get data by Http "POST" method.In my php script i have a key call "categoryWise" which has a value called "flower".I put all the necessary codes but it doesn't work and says The data couldn’t be read because it isn’t in the correct format.Please help.
let values = "categoryWise= nature"
let parameter = values.data(using: .utf8)
let url = "https://mahadehasancom.000webhostapp.com/WallpaperApp/php_scripts/getImageByCategory.php"
var request = URLRequest(url: URL(string: url)!)
request.httpMethod = "POST"
request.httpBody = parameter
request.setValue("application/x-content-type-options", forHTTPHeaderField: "Content-Type")
request.setValue("application/x-content-type-options", forHTTPHeaderField: "Accept")
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
if (error != nil)
{
print(error!)
}
else
{
do
{
let fetchData = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary
//print(fetchData)
let actorArray = fetchData?["result"] as? NSArray
for actor in actorArray!
{
let nameDict = actor as? NSDictionary
let name = nameDict?["date"] as! String
let countryname = nameDict?["category"] as! String
let imageUrl = nameDict?["url"] as! String
//let pageUrl = nameDict?["url"] as! String
authorArray.append(name)
titleArray.append(countryname)
imageURL.append(imageUrl)
//urlArray.append(pageUrl)
}
DispatchQueue.main.async {
self.CountryNameTable.reloadData()
}
print(authorArray)
print(titleArray)
print(imageURL)
print(urlArray)
}
catch let Error2
{
print(Error2.localizedDescription)
if let string = String(data: data!, encoding: .utf8)
{
print(string)
print(response!)
}
}
}
}
task.resume()
A few observations:
You shared PHP that is using $_POST. That means it's expecting x-www-form-urlencoded request. So, in Swift, you should set Content-Type of the request to be application/x-www-form-urlencoded because that's what you're sending. Likewise, in Swift, the Accept of the request should be application/json because your code will "accept" (or expect) a JSON response.
The values string you've supplied has a space in it. There can be no spaces in the key-value pairs that you send in a x-www-form-urlencoded request. (Note, if you have any non-alphanumeric characters in your values key pairs, you should be percent encoding them.)
In your Swift error handler, in addition to printing the error, you might want to try converting the data to a String, and looking to see what it says, e.g.
if let string = String(data: data!, encoding: .utf8) {
print(string)
}
You might also want to look at response and see what statusCode it reported. Having done that, you subsequently told us that it reported a statusCode of 500.
Status code 500 means that there was some internal error in the web service. (The code is 200 if successful.) This is generally a result of some error with the request not being handled correctly. For example, if the request neglected to format the request correctly and the web service doesn't anticipate/catch that, or if there was some other internal error on the web server, you could get 500 error code. For list of status codes, see http://w3.org/Protocols/rfc2616/rfc2616-sec10.html.
If the text in the body of the response from your web service is not illuminating, you might want to turn on error reporting (see How to get useful error messages in PHP? or How do I catch a PHP Fatal Error) and then look at the body of the response again. For example, you might include the following in your PHP:
<?php
function __fatalHandler() {
$error = error_get_last();
//check if it's a core/fatal error, otherwise it's a normal shutdown
if ($error !== NULL && in_array($error['type'], array(E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING))) {
header("Content-Type: application/json");
$result = Array("success" => false, "error" => $error);
echo json_encode($result);
die;
}
}
register_shutdown_function('__fatalHandler');
// the rest of your PHP here
?>
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:
Why aren't any results being printed?
I have been searching all over for an answer. I've tried many different example blocks of code. The print statements never fires unless an error is produced. For example: If I change the URL to "http" only with nothing else, I naturally get an error and it prints the error. However, any valid URL produces no result in the print statement.
func post()
{
let request = NSMutableURLRequest(URL: NSURL(string: "http://www.thebeerstore.ca")!)
request.HTTPMethod = "POST"
let postString = "experiment"
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)")
let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
print("responseString = \(responseString!)")
}
task.resume()
}
Edit: It works if I use a playground, but only in a playground.
In your application's Info.plist file, add the property App Transport Security Settings and under that, add Allow Arbitrary Loads and assign YES for it.
With the above settings in your Info.plist, the app should be able to load your http:// URLs as well
Note: I would recommend not to use the above settings in your
production build, it could result in security issues.
There is no good explanation for this, but having finally stuck this same problem code into my primary project, it now works perfectly ok. What changed??? Arrrrg! How many hours wasted and I still don't really know why it wasn't working outside of my primary app. Thanks for your help everyone.
Final code:
I do hope I can send over 100MB through a post request to be interpreted on the server side and store to the database. Haven't done this before. I'm a newbie.
func post()
{
let request = NSMutableURLRequest(URL: NSURL(string: "http://bruceexpress.com/database.php")!)
request.HTTPMethod = "POST"
request.HTTPBody = try! NSJSONSerialization.dataWithJSONObject(stores, options: [])
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let task = NSURLSession.sharedSession().dataTaskWithRequest(request)
{
data, response, error in
if error != nil {
print("error=\(error)")
return
}
print("response = \(response)")
let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
print("responseString = \(responseString!)")
}
task.resume()
}
Edit: Yes, you can post a huge block of data. Is this the correct way to do it? ( Forgive my silly questions, but I am recovering programming skills left over from 2001. I am a very outdated individual. )
Basically, what I have done is read all of the data on http://www.thebeerstore.ca, extracted every beer and its info and prices, and extracted every store and its info. I interpreted this data, converted it into a large JSON block, and sent it to my server to be interpreted by a php script which will store this data to a database.
Sound like the right thing to do, or is there a better way to fill the database?