retriving JSON from a url using objective C [closed] - ios

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I am new to objectiveC,
I have a problem in retrieving JSON type from a url, the url represent a web service which had built to return both JSON and XML, when I tried to consume the web service from the url the result was XML,
what I need is to determine the type of returning data to be JSON in the request.
by the way I am sure that the web service return both XML and JSON.
and here is my code where I get XML:
NSURL *url = [[NSURL alloc] initWithString:#"http://192.168.1.1:8080/test2/eattel/restaurants"];
NSString *result=[[NSString alloc] initWithContentsOfURL:url];
NSLog(#"%#",result);
the result is :
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<restaurantImpls>
<Resstaurant Name="Abo Alshamat" PhoneNumber="0991992994" MobileNumber="0991992993" LastName="Shame" ID="1" FirstName="Samer"/>
<Resstaurant Name="AL-Kamal" PhoneNumber="0992993995" MobileNumber="0992993994" LastName="Ali" ID="2" FirstName="Ahmad"/>
<Resstaurant Name="Abo-MAhmoud" MobileNumber="0993377800" ID="12"/>
<Resstaurant Name="Four Season" PhoneNumber="0993994996" MobileNumber="0993994995" LastName="Ammar" ID="3" FirstName="William"/>
<Resstaurant Name="uuuuu" MobileNumber="0999555777" LastName="William" ID="20" FirstName="Ammar"/>
<Resstaurant Name="NewOneFromI2" MobileNumber="0999888777" ID="18"/>
<Resstaurant Name="JOURY" PhoneNumber="0999999998" MobileNumber="0999998997" ID="4"/>
<Resstaurant Name="TestTestRestaurant,Ammar,Hamed" MobileNumber="202020" ID="19"/>
</restaurantImpls>
thank you for your time.

We couldnt set the response data type from our request. Response is set from the server. From your description(web service return both XML and JSON), my guess is you need to post a status variable which showing the return status like isXML. It's only my guess. You need to contact server side programmers about the implementation of this request.
EDIT
Try below code
responseData = [[NSMutableData alloc]init];
NSURL *url = [[NSURL alloc] initWithString:#"http://192.168.1.1:8080/test2/eattel/restaurants"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setValue:#"application/json" forHTTPHeaderField:#"accept"];
[request setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
(void)[NSURLConnection connectionWithRequest:req delegate:self];
Then You need to implement NSURLConnection Delegates.
#pragma mark - NSURLConnection Delegates
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[NSString alloc]initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(#"%#",responseString);
}

Related

iOS 9 ATS blocking HTTPS request to server with Self-Signed Certficate

This issue is all over Stack Overflow and I have spent the past 2 days trying countless combinations of ATP configurations and getting my app to work. I'm going to be thorough with my problem as it appears the tiniest thing can affect how to resolve this.
I have just recently set up an Ubuntu 14 server with SSL and TLS 1.2 enabled. On my server are my server-side scripts which my app depends on. In my app I use a NSMutableURLRequest to request my API from the server like so:
NSString * noteDataString = [NSString stringWithFormat:#"email=%#&password=%#&type=%#", companyEmail, companyPassword, #"login"];
NSData * postData = [noteDataString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString * postLength = [NSString stringWithFormat:#"%lu", (unsigned long)[postData length]];
NSMutableURLRequest * request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:#"https://mydomain.me:443/path/to/file.php"]];
[request setHTTPMethod:#"POST"];
[request setValue:postLength forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
NSHTTPURLResponse * urlResponse = nil;
NSError * error = nil;
NSData * responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&error];
NSString * result = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(#"Response Code: %ld", (long)[urlResponse statusCode]);
When I copy the url into Chrome the correct PHP return is shown. When requesting from Xcode 7 on iOS 9 I get this error:
NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9813)
I have used countless info.plist settings as seen across similar issues. I have tried disabling the need for forward secrecy, I have tried enabling arbitrary loads, I have tried using the exception domain mydomain.me and its subdomains. The only progress I achieve is an error code -9813 switching to -9802.
I am aware of adding delegate methods for NSURLRequest but these are never called and assumed redundant for solving this problem.
I built a lot of the app off a MAMP server using localhost and http and the requests worked when I enabled arbitrary loads then, so nothing wrong with my plist.
It's mind-boggling onto why I have a special case, and I knew Stack Overflow was the place for such situations!
Thanks, and I hope that this helps many more developers beyond me when solved.
Solution. Thank you everybody in the comments for pointing me in the right direction. The solution was to create an NSObject that handled NSURLRequests for this special case.
Credit to: https://www.cocoanetics.com/2010/12/nsurlconnection-with-self-signed-certificates/
The following is almost a direct copy from the tutorial in the link, but I figured it'd be easier to stay here.
So,
I had to create a new NSObject class with the following code:
BWWebService.h
#import <Foundation/Foundation.h>
#interface BWWebService : NSObject{
NSMutableData *receivedData;
NSURLConnection *connection;
NSStringEncoding encoding;
}
- (id)initWithURL:(NSURL *)url;
#end
BWWebService.m
#import "BWWebService.h"
#implementation BWWebService
- (id)initWithURL:(NSURL *)url{
if (self = [super init]){
NSURLRequest * request = [NSURLRequest requestWithURL:url];
connection = [NSURLConnection connectionWithRequest:request delegate:self];
[connection start];
}
return self;
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
// Every response could mean a redirect
receivedData = nil;
CFStringEncoding cfEncoding = CFStringConvertIANACharSetNameToEncoding((CFStringRef)
[response textEncodingName]);
encoding = CFStringConvertEncodingToNSStringEncoding(cfEncoding);
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
if (!receivedData){
// No store yet, make one
receivedData = [[NSMutableData alloc] initWithData:data];
}else{
// Append to previous chunks
[receivedData appendData:data];
}
}
// All worked
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSString * xml = [[NSString alloc] initWithData:receivedData encoding:encoding];
NSLog(#"%#", xml);
}
// And error occurred
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
NSLog(#"Error retrieving data, %#", [error localizedDescription]);
}
// To deal with self-signed certificates
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace{
return [protectionSpace.authenticationMethod
isEqualToString:NSURLAuthenticationMethodServerTrust];
}
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge{
if ([challenge.protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust]){
// we only trust our own domain
if ([challenge.protectionSpace.host isEqualToString:#"myuntrusteddomain.me"]){
NSURLCredential * credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];
[challenge.sender useCredential:credential forAuthenticationChallenge:challenge];
}
}
[challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}
#end
And if that wasn't enough, to make the request I used the following in replacement of my original request:
NSURL * url = [NSURL URLWithString:#"https://myuntrusteddomain.me:443/path/to/script.php"];
BWWebService * webService;
webService = [[BWWebService alloc] initWithURL:url];
I know that this does not POST data like the original, but that comes later. I am sure it will be a matter of handling the POST in initWithURL.
Thanks everyone.
Edit: It appears this application of the solution only works with Allows Arbitrary Loads set to YES.
Open Xcode, Command-Shift-2, enter 9813, and you immediately find -9813 = errSSLNoRootCert, which was to be expected since your self signed certificate has no root certificate, while -9802 = errSSLFatalAlert (you really buggered it up).
The problem seems to be that for security reasons, some software doesn't like self signed certificates. This can often be fixed by creating and installing your own root certificate, and having a certificate signed by your own root certificate.

HTTP(S) POST : connectionDidFinishLoading gets called with empty data, possible trust issue

I am trying to communicate with TSYS payment gateway which has an https server from my iOS application. My original code is given below.
-(void)postRequest:(NSString *)jsonBody{
NSData *requestData = [NSData dataWithBytes:[jsonBody UTF8String]
length:[jsonBody length]];
NSURL *url = [NSURL URLWithString:TSYS_URL];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url];
[request setHTTPMethod:#"POST"];
[request setValue:[NSString stringWithFormat:#"%d",[requestData length]]
forHTTPHeaderField:#"Content-Length"];
[request setValue:#"*/*" forHTTPHeaderField:#"Accept"];
[request setHTTPBody:requestData];
[[NSURLConnection alloc]initCustomURLWithRequest:request delegate:self ];
}
- (void)connection:(NSURLConnection *)connection
didReceiveResponse:(NSURLResponse *)response{
NSHTTPURLResponse* httpResponse = (NSHTTPURLResponse*)response;
int code = [httpResponse statusCode];
NSLog(#"http error code : %d", code);
[self.receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection
didReceiveData:(NSData *)data {
[self.receivedData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"receivedData.length : %d", [self.receivedData length]);
connection = nil;
}
- (void)connection:(NSURLConnection *)connection
didFailWithError:(NSError *)error {
connection = nil;
}
The payment gateway url is
#define TSYS_URL #"https://stagegw.transnox.com/servlets/TransNox_API_Server"
And I get this in console
http error code : 404
receivedData.length : 0
When I saw the log, the first port of call was about HTTPS SSL authentication, so I wrote a android project that do POST by trusting all certificate (not ideal, I know), and hurray I was getting correct response. But when I removed the part that enables HttpClient to trust all certificates, I got empty response(in Android).
To make iOS trust all certificate, I added below code
- (BOOL)connection:(NSURLConnection *)connection
canAuthenticateAgainstProtectionSpace:
(NSURLProtectionSpace *)protectionSpace {
//This always returns true
return [protectionSpace.authenticationMethod
isEqualToString:NSURLAuthenticationMethodServerTrust];
}
- (void)connection:(NSURLConnection *)connection
didReceiveAuthenticationChallenge:
(NSURLAuthenticationChallenge *)challenge {
if([challenge.protectionSpace.authenticationMethod
isEqualToString:NSURLAuthenticationMethodServerTrust]){
NSURLCredential *credential = [NSURLCredential
credentialForTrust:challenge.protectionSpace.serverTrust];
[challenge.sender useCredential:credential
forAuthenticationChallenge:challenge];
}
[challenge.sender
continueWithoutCredentialForAuthenticationChallenge:challenge];
}
Still I get the same error.
Ok my questions are
First and foremost, why is this not working? I need to get this
working , so that I can move forward with project. Since my project
is in beginning state, I don't mind if the solution is to trust all
certificates. I somehow need to get server talking.
The type of authentication challenge I am getting is
NSURLAuthenticationMethodServerTrust. Ideally I should get the
server issued certificate and make my NSURLConnection object trust
it. How could I get the certificate file from server?
I got it working at last. In the end, it was not an issue with authentication. Along with the all the code above, I had to pass a header field "User-Agent" with the request. When I passed it I started to get response from the server.

detect if website login failed objective-c?

Just a quick one how do i detect if a login failed here is my code:
- (IBAction)btnTimetable:(id)sender {
NSString *user = _txtUsername.text;
NSString *pass = _txtPassword.text;
NSString *content = [NSString stringWithFormat:#"username=%#&password=%#", user, pass];
NSData *data =[content dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *postlenght=[NSString stringWithFormat:#"%lu",(unsigned long)[data length]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:#"http://moodle.thomroth.ac.uk/login/index.php?mode=login"]];
[request setHTTPMethod:#"POST"];
[request setValue:postlenght forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Length"];
[request setHTTPBody:data];
//NSError *error=nil;
//NSURLResponse *response=nil;
//NSData *result=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
[_webView loadRequest:request];
[self performSelector:#selector(parseTimetable) withObject:nil afterDelay:3.0];
}
i dont even know where to start on this one is there a delegate method to detect such actions ?
As stated in the official Developer forums, UIWebView does not support authentication challenges in iOS. Please read here (requires developer account): UIWebView does not directly support authentication challenges
sendSynchronousRequest:returningResponse:error: should return nil and the status code of the returned response should equal 401 (Unauthorized):
[(NSHTTPURLRequest*)response statusCode] == 401
I would guess, the error parameter should be set to a corresponding error (please check this through printing it to the console).
If you use the delegate approach of NSURLConnection the situation is different:
When NSURLConnection receives a 401 (for example, the connection requires credentials for authentication, or a previous authentication attempt failed), it does invoke the delegate
- (void)connection:(NSURLConnection *)connection
willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;
if implemented, otherwise it invokes these (now considered obsolete methods):
- (BOOL)connection:(NSURLConnection *)connection
canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace;
- (void)connection:(NSURLConnection *)connection
didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;
- (BOOL)connectionShouldUseCredentialStorage:(NSURLConnection *)connection;
if implemented.
The official documentation provided more information: NSURLConnectionDelegate Protocol Reference.
You can cancel the authentication request, if you decide to do so. As a result, the connection can fail.
If the connection fails, connection:didFailWithError will be invoked.
If you really want to do it using UIWebView you could use it's delegate method and parse code answer of your website.
- (void)webViewDidFinishLoad:(UIWebView *)webView {
NSString *webSource = [_web stringByEvaluatingJavaScriptFromString:#"document.body.innerHTML"];
}

NSURLConnection GET REQUEST

I came across NSURLConnection, I used it before, simply on request, and getting data and parsing it. However this time web developer has developed GET and POST requests.
I want through many tutorials and stack question and tried to get desired result.
As I see there is sometime request, like this
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:#"URL"]
cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData
timeoutInterval:10];
[request setHTTPMethod: #"GET"];
NSError *requestError;
NSURLResponse *urlResponse = nil;
NSData *response1 = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&requestError];
also few others I have seen.
I looks easy but I am unable to find what is required for any POST and GET request.
The data which I have received from my web developer is
SOAP 1.2
POST /DEMOService/DEMO.asmx HTTP/1.1
Host: projects.demosite.com
Content-Type: application/soap+xml; charset=utf-8
Content-Length: length
and in return there will be GET and POST
The following is a sample HTTP GET request and response. The placeholders shown need to be replaced with actual values.
GET /DEMOService/DEMO.asmx/VerifyLogin?username=string&password=string&AuthenticationKey=string HTTP/1.1
Host: projects.demosite.com
I am well-aware of delegates of NSURLConnections, which are following..
#pragma mark NSURLConnection Delegate Methods
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
// A response has been received, this is where we initialize the instance var you created
// so that we can append data to it in the didReceiveData method
// Furthermore, this method is called each time there is a redirect so reinitializing it
// also serves to clear it
_responseData = [[NSMutableData alloc] init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
// Append the new data to the instance variable you declared
[_responseData appendData:data];
}
- (NSCachedURLResponse *)connection:(NSURLConnection *)connection
willCacheResponse:(NSCachedURLResponse*)cachedResponse {
// Return nil to indicate not necessary to store a cached response for this connection
return nil;
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
// The request is complete and data has been received
// You can parse the stuff in your instance variable now
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
// The request has failed for some reason!
// Check the error var
}
THE ONLY THING WHERE I AM STUCK IS
How to write request where I have pass arguments, in GET or POST request.
Thanks
If your arguments are being sent in the URL itself (e.g., as part of the URL path or query string), then you just need to include them in the NSURL argument. For instance, you might have the following:
NSString *urlString = [NSString stringWithFormat:#"https://hostname/DEMOService/DEMO.asmx/VerifyLogin?username=%#&password=%#&AuthenticationKey=%#",
username,
password,
authenticationKey];
NSURL *url = [NSURL URLWithString:urlString];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData
timeoutInterval:10];
where username, password, and authenticationKey are local variables you set elsewhere.
Your response from the server is stored by the data contained in the NSData instance returned by -[NSURLConnection sendSynchronousRequest:returningResponse:error:].
So in your example, your response above would be stored in the response1 variable. And you can convert this to a string and/or parse it as needed.

Finding whether a URL is valid and does it exists? [duplicate]

This question already has answers here:
URL Validation (Objective-C)
(4 answers)
Closed 9 years ago.
I want to find that whether the URL im giving is valid or not, and whether it exists in internet or not..
Is there any way to do that using objective-C?
You can see if a URL is valid or not by doing the following:
NSString *urlString = ... // some URL to check
NSURL *url = [NSURL URLWithString:urlString];
if (url) {
// valid URL (meaning it is the proper format)
}
To see if the URL exists in the Internet, you need to perform a HEAD request and check the result. This is more efficient than loading all of the data for the URL.
NSMutableURLRequest request = [NSMutableURLRequest requestWithURL:inURL];
[request setHTTPMethod:#"HEAD"];
NSURLConnection connection = [NSURLConnection connectionWithRequest:request delegate:self];
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
if ([(NSHTTPURLResponse *)response statusCode] == 200) {
// url exists
}
}

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