Making a GET request using NSURL not working - ios

I am trying to get a simple GET request to work for my api. But it doesnt seem to work, and I am not sure why.
My code is as follows
Edit, also tried NSURLCredential But that does not seem to work either
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
NSString *urlAsString = #"https://www.test.com/api/v1/user/logout/";
NSURL *url = [NSURL URLWithString:urlAsString];
NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url]; [urlRequest setTimeoutInterval:30.0f];
[urlRequest setHTTPMethod:#"GET"];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response,NSData *data, NSError *error) {
if ([data length] >0 && error == nil){
NSString *html = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"HTML = %#", html); }
else if ([data length] == 0 && error == nil){
NSLog(#"Nothing was downloaded."); }
else if (error != nil){
NSLog(#"Error happened = %#", error); }
}];
}
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace {
return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
[challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
[challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}
My API spits out json. So I should be getting a json object back that says
success: False
reason: 'Already Logged out'
But instead it gives me the following error
2013-03-07 16:24:44.038 test[8957:1d03] Error happened = Error Domain=NSURLErrorDomain Code=-1012 "The operation couldn’t be completed. (NSURLErrorDomain error -1012.)" UserInfo=0x715db20 {NSErrorFailingURLKey=https://www.test.com/api/v1/user/logout/, NSErrorFailingURLStringKey=https://www.test.com/api/v1/user/logout/, NSUnderlyingError=0x7181cb0 "The operation couldn’t be completed. (kCFErrorDomainCFNetwork error -1012.)"}
Method 2
after some reseach, I found another way of sending get requests, and this method seems to work fine
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
NSError *error = nil;
NSURL *url = [NSURL URLWithString:#"https://www.test.com/api/v1/user/logout/"];
NSString *json = [NSString stringWithContentsOfURL:url
encoding:NSASCIIStringEncoding
error:&error];
if(!error) {
NSData *jsonData = [json dataUsingEncoding:NSASCIIStringEncoding];
NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:jsonData
options:kNilOptions
error:&error];
BOOL success = [[jsonDict objectForKey:#"success"] boolValue];
if (!success) {
NSString *reason = [jsonDict objectForKey:#"reason"];
NSLog(#"Cannot log out, as user %#", reason);
}
//NSLog(#"JSON: %#", jsonDict);
}else{
NSLog(#"\nJSON: %# \n Error: %#", json, error);
}
});

The solution to the problem was in the API itself. The API was supposed to send HTTPUnauthorized signal if the user is already logged out. And since that was the case, iOS was showing all these exceptions. when I dropped that and just sent back a simple json response, everything got fixed.

Related

error 401 when i request to get all contacts using GDATA

i am using Gdata and already suceessfully login gmail and call below method
- (void)viewController:(GTMOAuth2ViewControllerTouch *)viewController
finishedWithAuth:(GTMOAuth2Authentication *)auth{
if (error != nil) {
}
else{
// i got successful login here
self.auth=auth;
}
}
in above method i got Authentifacation token and etc.
Now
NSString *urlStr = #"https://www.google.com/m8/feeds/contacts/default/full";
NSURL *url = [NSURL URLWithString:urlStr];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[self.auth authorizeRequest:request
completionHandler:^(NSError *error) {
NSString *output = nil;
if (error) {
output = [error description];
} else {
// Synchronous fetches like this are a really bad idea in Cocoa applications
//
// For a very easy async alternative, we could use GTMHTTPFetcher
NSURLResponse *response = nil;
NSData *data = [NSURLConnection sendSynchronousRequest:request
returningResponse:&response
error:&error];
if (data) {
// API fetch succeeded
output = [[[NSString alloc] initWithData:data
encoding:NSUTF8StringEncoding] autorelease];
} else {
// fetch failed
output = [error description];
}
}
}];
but i got error 401
please helpful me

Using sendAsynchronousRequest:queue:completionHandler: for URL request

I'm working on an update of an iOS app that another developer created. He was using ASIHTTPRequest to handle http requests. However, the version of the app I have to work with crashes. Since ASIHTTPRequest is not being updated anymore, I thought then that I should switch to using AFNetworking, but it's far too complicated for me to figure out.
So finally I thought I could just use NSURLConnection on its own.
Here is the original code that I'm trying to replace:
-(NSArray*)readUTF16LEFeed:(NSURL*) urlToRead{
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:urlToRead];
[request startSynchronous];
NSError *error = [request error];
if (!error) {
lastModified = [NSDate date];
NSData *response = [request responseData];//UTF-16LE
NSString* responseString = [[NSString alloc] initWithData:response encoding:NSUTF16LittleEndianStringEncoding];
DLog(#"string is: %#",responseString);
responseString = [responseString stringByReplacingOccurrencesOfString:#"ISO-8859-1" withString:#"UTF16-LE"];
NSData* data = [responseString dataUsingEncoding:NSUTF16LittleEndianStringEncoding];
return [self parseNamesFromXML:data];
}
return nil;
}
And here is what I'm trying to use instead:
-(NSArray*)readUTF16LEFeed:(NSURL*) urlToRead{
NSURLRequest *request = [NSURLRequest requestWithURL:urlToRead];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *error ) {
if ([data length] >0 && error == nil)
{
// DO YOUR WORK HERE
lastModified = [NSDate date];
// NSData *response = [request responseData];//UTF-16LE
NSString* responseString = [[NSString alloc] initWithData:data encoding: NSUTF16LittleEndianStringEncoding];
DLog(#"string is: %#",responseString);
responseString = [responseString stringByReplacingOccurrencesOfString:#"ISO-8859-1" withString:#"UTF16-LE"];
NSData* data = [responseString dataUsingEncoding:NSUTF16LittleEndianStringEncoding];
return [self parseNamesFromXML:data];
}
else if ([data length] == 0 && error == nil)
{
NSLog(#"Nothing was downloaded.");
}
else if (error != nil){
NSLog(#"Error = %#", error);
}
}];
return nil;
}
However, I'm getting the error "Incompatible block pointer types sending NSArray to parameter of type void. And also "Control may reach end of non-void block."
How can I get this to work?
Make return type of your method as void. Dont return anything. Just call [self parseNamesFromXML:data]; method.
-(void)readUTF16LEFeed:(NSURL*) urlToRead{
NSURLRequest *request = [NSURLRequest requestWithURL:urlToRead];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *error ) {
if ([data length] >0 && error == nil)
{
// DO YOUR WORK HERE
lastModified = [NSDate date];
// NSData *response = [request responseData];//UTF-16LE
NSString* responseString = [[NSString alloc] initWithData:data encoding: NSUTF16LittleEndianStringEncoding];
DLog(#"string is: %#",responseString);
responseString = [responseString stringByReplacingOccurrencesOfString:#"ISO-8859-1" withString:#"UTF16-LE"];
NSData* data = [responseString dataUsingEncoding:NSUTF16LittleEndianStringEncoding];
[self parseNamesFromXML:data];
}
else if ([data length] == 0 && error == nil)
{
NSLog(#"Nothing was downloaded.");
}
else if (error != nil){
NSLog(#"Error = %#", error);
}
}];
}
In parseNamesFromXML method, process your results and assign results array to a property. You can access it where ever you want.
-(void) parseNamesFromXML:(NSData *)xmlData
{
NSError *error;
//DLog(#"data is %#", [[NSString alloc] initWithData:xmlData encoding:NSUTF8StringEncoding ]);
GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithData:xmlData options:0 error:&error];
if (doc)
{
self.dataArray = [self parseXmlDoc:doc];
}
}
The completion block is called asynchronously, so by the time your code reaches return [self parseNamesFromXML:data]; the methods scope is already done (meaning the method returned nil.
Try using [NSURLConnection sendSynchronousRequest:returningResponse:error:] instead, since the original code is also synchronous.
Edit:
As Julian Król suggested, if you return something within a block, it will be counted as the return value of this block, not of the original method. But since the block does not have a return value, you'll get the compiler error.

NSURLConnection wrong order

I have a NSURLConnection (two of them), and they're running in the wrong order.
Here's my method:
- (void)loginToMistarWithPin:(NSString *)pin password:(NSString *)password {
NSURL *url = [NSURL URLWithString:#"https://mistar.oakland.k12.mi.us/novi/StudentPortal/Home/Login"];
//Create and send request
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
[request setHTTPMethod:#"POST"];
NSString *postString = [NSString stringWithFormat:#"Pin=%#&Password=%#",
[self percentEscapeString:pin],
[self percentEscapeString:password]];
NSData * postBody = [postString dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:postBody];
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
// do whatever with the data...and errors
if ([data length] > 0 && error == nil) {
NSError *parseError;
NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:data options:0 error:&parseError];
if (responseJSON) {
// the response was JSON and we successfully decoded it
NSLog(#"Response was = %#", responseJSON);
} else {
// the response was not JSON, so let's see what it was so we can diagnose the issue
NSString *loggedInPage = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"Response was not JSON (from login), it was = %#", loggedInPage);
}
}
else {
NSLog(#"error: %#", error);
}
}];
//Now redirect to assignments page
NSURL *homeURL = [NSURL URLWithString:#"https://mistar.oakland.k12.mi.us/novi/StudentPortal/Home/PortalMainPage"];
NSMutableURLRequest *requestHome = [[NSMutableURLRequest alloc] initWithURL:homeURL];
[request setHTTPMethod:#"POST"];
[NSURLConnection sendAsynchronousRequest:requestHome queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *homeResponse, NSData *homeData, NSError *homeError)
{
// do whatever with the data...and errors
if ([homeData length] > 0 && homeError == nil) {
NSError *parseError;
NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:homeData options:0 error:&parseError];
if (responseJSON) {
// the response was JSON and we successfully decoded it
NSLog(#"Response was = %#", responseJSON);
} else {
// the response was not JSON, so let's see what it was so we can diagnose the issue
NSString *homePage = [[NSString alloc] initWithData:homeData encoding:NSUTF8StringEncoding];
NSLog(#"Response was not JSON (from home), it was = %#", homePage);
}
}
else {
NSLog(#"error: %#", homeError);
}
}];
}
- (NSString *)percentEscapeString:(NSString *)string
{
NSString *result = CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
(CFStringRef)string,
(CFStringRef)#" ",
(CFStringRef)#":/?#!$&'()*+,;=",
kCFStringEncodingUTF8));
return [result stringByReplacingOccurrencesOfString:#" " withString:#"+"];
}
So, it's two NSURLConnection's that are added to the [NSOperationQueue mainQueue]. What my output is showing me is that the second NSURLConnection is running before the first one. So it tries to go to the page where I download data before I'm logged in, so it (obviously) returns a "You're not logged in" error.
How do I schedule them one after another?
The issue, as I suspect you have realized, is that you're doing asynchronous network requests (which is good; you don't want to block the main queue), so there's no assurance of the order they'll finish.
The quickest and easiest answer is to simply put the call to the second request inside the completion block of the first one, not after it. You don't want to be making that second one unless the first one succeeded anyway.
To keep your code from getting unwieldy, separate the login from the request for main page. And you can use the completion block pattern which is common with asynchronous methods. You add a parameter to loginToMistarWithPin that specifies what it should do when the request finishes. You might have one completion block handler for success, and one for failure:
- (void)loginToMistarWithPin:(NSString *)pin password:(NSString *)password success:(void (^)(void))successHandler failure:(void (^)(void))failureHandler {
NSURL *url = [NSURL URLWithString:#"https://mistar.oakland.k12.mi.us/novi/StudentPortal/Home/Login"];
//Create and send request
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
[request setHTTPMethod:#"POST"];
NSString *postString = [NSString stringWithFormat:#"Pin=%#&Password=%#",
[self percentEscapeString:pin],
[self percentEscapeString:password]];
NSData * postBody = [postString dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:postBody];
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
// do whatever with the data...and errors
if ([data length] > 0 && error == nil) {
NSError *parseError;
NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:data options:0 error:&parseError];
if (responseJSON) {
// the response was JSON and we successfully decoded it
NSLog(#"Response was = %#", responseJSON);
// assuming you validated that everything was successful, call the success block
if (successHandler)
successHandler();
} else {
// the response was not JSON, so let's see what it was so we can diagnose the issue
NSString *loggedInPage = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"Response was not JSON (from login), it was = %#", loggedInPage);
if (failureHandler)
failureHandler();
}
}
else {
NSLog(#"error: %#", error);
if (failureHandler)
failureHandler();
}
}];
}
- (void)requestMainPage {
//Now redirect to assignments page
NSURL *homeURL = [NSURL URLWithString:#"https://mistar.oakland.k12.mi.us/novi/StudentPortal/Home/PortalMainPage"];
NSMutableURLRequest *requestHome = [[NSMutableURLRequest alloc] initWithURL:homeURL];
[requestHome setHTTPMethod:#"GET"]; // this looks like GET request, not POST
[NSURLConnection sendAsynchronousRequest:requestHome queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *homeResponse, NSData *homeData, NSError *homeError)
{
// do whatever with the data...and errors
if ([homeData length] > 0 && homeError == nil) {
NSError *parseError;
NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:homeData options:0 error:&parseError];
if (responseJSON) {
// the response was JSON and we successfully decoded it
NSLog(#"Response was = %#", responseJSON);
} else {
// the response was not JSON, so let's see what it was so we can diagnose the issue
NSString *homePage = [[NSString alloc] initWithData:homeData encoding:NSUTF8StringEncoding];
NSLog(#"Response was not JSON (from home), it was = %#", homePage);
}
}
else {
NSLog(#"error: %#", homeError);
}
}];
}
Then, when you want to login, you can do something like:
[self loginToMistarWithPin:#"1234" password:#"pass" success:^{
[self requestMainPage];
} failure:^{
NSLog(#"login failed");
}];
Now, change those successHandler and failureHandler block parameters to include whatever data you need to pass back, but hopefully it illustrates the idea. Keep your methods short and tight, and use completion block parameters to specify what an asynchronous method should do when it's done.
Can you check the below link. It is about forcing one operation to wait for another.
NSOperation - Forcing an operation to wait others dynamically
Hope this helps.

issue with getting data from url

Here is the code I wrote
NSString *str = [NSString stringWithFormat:#"https://graph.facebook.com/me?access_token=CAADbwxRRgq8BANULcGGn3d4NPZB4LlP3tCL9YjYH3Nd0fD2XvgjG0qTECEmOsFhNhcu4NCdgYzQK3lYaATiedLRP4ZAIRgf8FBtDBYd22z5BrMabHlex12nZAbm8UfJTrPVRw5rjN8abi9"];
NSURL* url = [NSURL URLWithString:[str stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSError* error = nil;
NSData* data = [NSData dataWithContentsOfURL:url options:NSDataReadingUncached error:&error];
if (error) {
NSLog(#"%#", [error localizedDescription]);
} else {
NSLog(#"Data has loaded successfully.");
}
I got the error
Error Domain=NSCocoaErrorDomain Code=256 "The operation couldn’t be
completed. (Cocoa error 256.)" UserInfo=0x218446a0
{NSURL=https://graph.facebook.com/me?access_token=CAADbwxRRgq8BANULcGGn3d4NPZB4LlP3tCL9YjYH3Nd0fD2XvgjG0qTECEmOsFhNhcu4NCdgYzQK3lYaATiedLRP4ZAIRgf8FBtDBYd22z5BrMabHlex12nZAbm8UfJTrPVRw5rjN8abi9ZBoVD1DYVZCo8hcZC0n2CnMyk3ryeCQntRpdZCc2e}
Try:
NSString *str = [NSString stringWithFormat:#"https://graph.facebook.com/me?access_token=CAADbwxRRgq8BANULcGGn3d4NPZB4LlP3tCL9YjYH3Nd0fD2XvgjG0qTECEmOsFhNhcu4NCdgYzQK3lYaATiedLRP4ZAIRgf8FBtDBYd22z5BrMabHlex12nZAbm8UfJTrPVRw5rjN8abi9"];
NSURL* url = [NSURL URLWithString:[str stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSError* error = nil;
NSData* data = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:30] returningResponse:nil error:&error];
if (error) {
NSLog(#"%#", [error localizedDescription]);
} else {
NSLog(#"Data has loaded successfully.");
}
Albeit, I have no idea why your other request fails. Error code 256 isn't very descriptive.
Here is a nice explanation of why NSCocoaErrorDomain occurs.
NSData dataWithContentsOfURL: not returning data for URL that shows in browser
Read it and see if any of the suggestions in that answer might be useful to you.

objectFromJSONString in JSONKit.h returns null in iOS

Please do the following to reproduce the problem
NSString *url = #"http://qdreams.com/laura/index.php?request=EventWeekListings&year=2012&month=10&day=22";
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
NSString *json = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"%#" , json);
NSDictionary *deserializedData = [json objectFromJSONString];
deserializedData would contain nil. Expected behavior is to return proper dictionary.
Is that because total number of JSON dictionary elements exceed a certain threshold?
I would appreciate any help in this matter.
Why not just use the NSJSONSerialization method JSONObjectWithData:options:error: it worked fine for me.
NSString *url = #"http://qdreams.com/laura/index.php?request=EventWeekListings&year=2012&month=10&day=22";
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
NSArray *arr = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
NSLog(#"%#",arr);
After Edit: I ran the code again this morning, and like you I got null. The problem with dataWithContentsOfURL. is that you have no control and no way to know what happened if something went wrong. So, I retested with the code below:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
[self loadData];
}
-(void) loadData {
NSLog(#"loadData...");
self.receivedData = [[NSMutableData alloc] init];
NSURL *url = [NSURL URLWithString:#"http://qdreams.com/laura/index.php?request=EventWeekListings&year=2012&month=10&day=22"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL: url cachePolicy: NSURLRequestUseProtocolCachePolicy timeoutInterval: 10.0];
[NSURLConnection connectionWithRequest:request delegate:self];
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
NSLog(#"didReceiveResponse...");
[self.receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
NSLog(#"didReceiveData...");
NSLog(#"Succeeded! Received %ld bytes of data",[data length]);
[self.receivedData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
NSLog(#"didFailWithError...");
NSLog(#"Connection failed! Error - %# %#",[error localizedDescription],[[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
//lblError.text = [NSString stringWithFormat:#"Connection failed! Error - %#",[error localizedDescription]];
self.receivedData = nil;
}
-(void) connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"connectionDidFinishLoading...");
NSError *error = nil;
id result = [NSJSONSerialization JSONObjectWithData:self.receivedData options:kNilOptions error:&error];
if (error) {
NSLog(#"%#",error.localizedDescription);
NSLog(#"%#",[[NSString alloc] initWithData:self.receivedData encoding:NSUTF8StringEncoding]);
}else{
NSLog(#"Finished...Download/Parsing successful");
if ([result isKindOfClass:[NSArray class]])
NSLog(#"%#",result);
}
}
There was an error, and the log of error.localizesDescription was: "The data couldn’t be read because it has been corrupted". So, it appears that there is something wrong with what's coming back from the server which prevents the JSON parser from working correctly. I also printed out the string along with the error message. Maybe you can look at it carefully and try to figure out what's wrong with the data.
looking at your json you start with the array value (using square brackets) without a name. try reformatting you response with something like this:
{"results":[...the rest of your response..]}

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