I'm trying to test a NSJSONSerialization with this URL ; the link works, and the app runs, but when I log the serialization, I get a null result.
Can anyone tell me what I'm doing wrong? Code:
#implementation ViewController
- ( void )viewDidLoad
{
[super viewDidLoad];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:#"https:franciscocosta.net/lisbon-spots"]];
NSURLSessionDataTask *task = [[self getURLSession] dataTaskWithRequest:request completionHandler:^( NSData *data, NSURLResponse *response, NSError *error )
{dispatch_async( dispatch_get_main_queue(),
^{
NSError *jsonError;
NSArray *parsedJSONArray = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&jsonError];
NSLog( #"%#", parsedJSONArray );
} );
}];
[task resume];
}
- ( NSURLSession * )getURLSession
{
static NSURLSession *session = nil;
static dispatch_once_t onceToken;
dispatch_once( &onceToken,
^{
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
session = [NSURLSession sessionWithConfiguration:configuration];
} );
return session;
}
It looks like your JSON is not well-formed.
If type your link into Safari, then copy the resulting JSON and paste it into a JSON verifier like JSONLint, it shows an error on line 25. It looks like there is closing bracket (]) that doesn't belong there. It appears that that JSON contains 2 root array objects, which I don't think is valid.
If you refactor it to contain a single array of dictionaries, it passes the JSONLint test as valid JSON.
Related
I am new to Objective C and iOS development in general. I am trying to create an app that would make an http request and display the contents on a label.
When I started testing I noticed that the label was blank even though my logs showed that I had data back. Apparently this happens because the the response is not ready when the label text gets updated.
I put a loop on the top to fix this but I am almost sure there's got to be a better way to deal with this.
ViewController.m
- (IBAction)buttonSearch:(id)sender {
HttpRequest *http = [[HttpRequest alloc] init];
[http sendRequestFromURL: #"https://en.wiktionary.org/wiki/incredible"];
//I put this here to give some time for the url session to comeback.
int count;
while (http.responseText ==nil) {
self.outputLabel.text = [NSString stringWithFormat: #"Getting data %i ", count];
}
self.outputLabel.text = http.responseText;
}
HttpRequest.h
#import <Foundation/Foundation.h>
#interface HttpRequest : NSObject
#property (strong, nonatomic) NSString *responseText;
- (void) sendRequestFromURL: (NSString *) url;
- (NSString *) getElementBetweenText: (NSString *) start andText: (NSString *) end;
#end
HttpRequest.m
#implementation HttpRequest
- (void) sendRequestFromURL: (NSString *) url {
NSURL *myURL = [NSURL URLWithString: url];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL: myURL];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *task = [session dataTaskWithRequest: request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
self.responseText = [[NSString alloc] initWithData: data
encoding: NSUTF8StringEncoding];
}];
[task resume];
}
Thanks a lot for the help :)
Update
After reading a lot for the very useful comments here I realized that I was missing the whole point. So technically the NSURLSessionDataTask will add task to a queue that will make the call asynchronously and then I have to provide that call with a block of code I want to execute when the thread generated by the task has been completed.
Duncan thanks a lot for the response and the comments in the code. That helped me a lot to understand.
So I rewrote my procedures using the information provided. Note that they are a little verbose but, I wanted it like that understand the whole concept for now. (I am declaring a code block rather than nesting them)
HttpRequest.m
- (void) sendRequestFromURL: (NSString *) url
completion:(void (^)(NSString *, NSError *))completionBlock {
NSURL *myURL = [NSURL URLWithString: url];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL: myURL];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *task = [session dataTaskWithRequest: request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
//Create a block to handle the background thread in the dispatch method.
void (^runAfterCompletion)(void) = ^void (void) {
if (error) {
completionBlock (nil, error);
} else {
NSString *dataText = [[NSString alloc] initWithData: data encoding: NSUTF8StringEncoding];
completionBlock(dataText, error);
}
};
//Dispatch the queue
dispatch_async(dispatch_get_main_queue(), runAfterCompletion);
}];
[task resume];
}
ViewController.m
- (IBAction)buttonSearch:(id)sender {
NSString *const myURL = #"https://en.wiktionary.org/wiki/incredible";
HttpRequest *http = [[HttpRequest alloc] init];
[http sendRequestFromURL: myURL
completion: ^(NSString *str, NSError *error) {
if (error) {
self.outputText.text = [error localizedDescription];
} else {
self.outputText.text = str;
}
}];
}
Please feel free to comment on my new code. Style, incorrect usage, incorrect flow; feedback is very important in this stage of learning so I can become a better developer :)
Again thanks a lot for the replies.
You know what, use AFNetworking to save your life.
Or just modify your HttpRequest's sendRequestFromURL:
- (void)sendRequestFromURL:(NSString *)url completion:(void(^)(NSString *str, NSError *error))completionBlock {
NSURL *myURL = [NSURL URLWithString: url];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL: myURL];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *task = [session dataTaskWithRequest: request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
dispatch_async(dispatch_get_main_queue(), ^{
if (error) {
completionBlock(nil, error);
} else {
completionBlock([[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding], error);
}
});
}];
[task resume];
}
and invoke like this
[http sendRequestFromURL:#"https://en.wiktionary.org/wiki/incredible" completion:^(NSString *str, NSError *error) {
if (!error) {
self.outputLabel.text = str;
}
}];
Rewrite your sendRequestFromURL function to take a completion block:
- (void) sendRequestFromURL: (NSString *) url
completion: (void (^)(void)) completion
{
NSURL *myURL = [NSURL URLWithString: url];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL: myURL];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *task = [session dataTaskWithRequest: request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
{
self.responseText = [[NSString alloc] initWithData: data
encoding: NSUTF8StringEncoding];
if (completion != nil)
{
//The data task's completion block runs on a background thread
//by default, so invoke the completion handler on the main thread
//for safety
dispatch_async(dispatch_get_main_queue(), completion);
}
}];
[task resume];
}
Then, when you call sendRequestFromURL, pass in the code you want to run when the request is ready as the completion block:
[self.sendRequestFromURL: #"http://www.someURL.com&blahblahblah",
completion: ^
{
//The code that you want to run when the data task is complete, using
//self.responseText
}];
//Do NOT expect the result to be ready here. It won't be.
The code above uses a completion block with no parameters because your code saved the response text to an instance variable. It would be more typical to pass the response data and the NSError as parameters to the completion block. See #Yahoho's answer for a version of sendRequestFromURL that takes a completion block with a result string and an NSError parameter).
(Note: I wrote the code above in the SO post editor. It probably has a few syntax errors, but it's intended as a guide, not code you can copy/paste into place. Objective-C block syntax is kinda nasty and I usually get it wrong the first time at least half the time.)
If you want easy way then Don't make separate class for call webservice. Just make meethod in viewController.m instead. I mean write sendRequestFromURL in your viewController.m and update your label's text in completion handler something like,
- (void) sendRequestFromURL: (NSString *) url {
NSURL *myURL = [NSURL URLWithString: url];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL: myURL];
NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *task = [session dataTaskWithRequest: request
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
dispatch_async(dispatch_get_main_queue(), ^{
self.responseText = [[NSString alloc] initWithData: data
encoding: NSUTF8StringEncoding];
self.outputLabel.text = self.responseText;
})
}];
[task resume];
}
I have a singleton class where i have implemented a method to parse json data through URL. The code is as below
-(id)parseJsonDataWIthURL:(NSString *)url :(NSString*)datumm
{
NSMutableDictionary *arrrrr=[[NSMutableDictionary alloc]init];
NSMutableURLRequest *reqqq=[[NSMutableURLRequest alloc]initWithURL:[NSURL URLWithString:url]];
NSData *dataaa=[datumm dataUsingEncoding:NSUTF8StringEncoding];
[reqqq setHTTPMethod:#"POST"];
[reqqq setHTTPBody:dataaa];
NSURLSessionConfiguration *configg=[NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession*sessionn=[NSURLSession sessionWithConfiguration:configg delegate:nil delegateQueue:[NSOperationQueue mainQueue]];
NSURLSessionDataTask *taskk=[sessionn dataTaskWithRequest:reqqq completionHandler:^(NSData *data,NSURLResponse *responce,NSError *error){
if(error)
{
NSLog(#"%#", [error localizedDescription]);
}else{
NSMutableDictionary *d = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments|NSJSONReadingMutableContainers error:&error];
NSLog(#"data %#",d);
[arrrrr setDictionary:d];
}
}];
[taskk resume];
return arrrrr;
}
The method returns no values, it is because the blocks takes time to execute within that method returns the result. So is there any way to wait until block completes and return the value.
ragul ml,
Simplest solution I can suggest is to use blocks :)
Here is how you can achieve it :) modify -(id)parseJsonDataWIthURL:(NSString *)url :(NSString*)datumm to,
-(void)parseJsonDataWIthURL:(NSString *)url :(NSString*)datumm withCompletionBlock:(void(^)(NSMutableArray *))completionBlock
{
NSMutableDictionary *arrrrr=[[NSMutableDictionary alloc]init];
NSMutableURLRequest *reqqq=[[NSMutableURLRequest alloc]initWithURL:[NSURL URLWithString:url]];
NSData *dataaa=[datumm dataUsingEncoding:NSUTF8StringEncoding];
[reqqq setHTTPMethod:#"POST"];
[reqqq setHTTPBody:dataaa];
NSURLSessionConfiguration *configg=[NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession*sessionn=[NSURLSession sessionWithConfiguration:configg delegate:nil delegateQueue:[NSOperationQueue mainQueue]];
NSURLSessionDataTask *taskk=[sessionn dataTaskWithRequest:reqqq completionHandler:^(NSData *data,NSURLResponse *responce,NSError *error){
if(error)
{
NSLog(#"%#", [error localizedDescription]);
completionBlock(nil)
}else{
NSMutableDictionary *d = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments|NSJSONReadingMutableContainers error:&error];
NSLog(#"data %#",d);
[arrrrr setDictionary:d];
if (completionBlock) {
completionBlock(arrrrr);
}
}
}];
[taskk resume];
}
finally modify your call as,
[[YourSingletonClass sharedInstance] parseJsonDataWIthURL:your_url :datumm withCompletionBlock:^(NSMutableArray *array) {
if (array){
//web service is successful
}
}];
Good day.Im requesting to some server and defiantly I'm having some JSON data there so I'm trying to parse it.Im stuck at the point where I'm actually parsing it.So i have method called parseJson which requires NSDictionry as parameter so here how it looks
-(void)parseJson:(NSDictionary*)jsonData{
[jsonData valueForKey:#"email"];
}
as you can see not much here but I'm getting exeption when the code reaches at
[jsonData valueForKey:#"email"];
I have pretty much started developing for iOS from yesterday and the exception is hell as weird for me which is the next.
this class is not key value coding-compliant for the key email.'
So by googling i found nothing...and pretty much in every JSON PARSING tutorial this one line code is written so I'm very much confused what does this exception means....Please help,what am i doing wrong?
FULL REQUEST CODE
-(void) makeRequest{
// Create the request.
__block NSString *returnResponse = #"hello";
NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *defaultSession = [NSURLSession sessionWithConfiguration: defaultConfigObject delegate: nil delegateQueue: [NSOperationQueue mainQueue ]];
//Create an URLRequest
NSURL *url = [NSURL URLWithString:#"http://jsonplaceholder.typicode.com/posts"];
NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:url];
//Create POST Params and add it to HTTPBody
NSString *params = #"api_key=APIKEY&email=example#example.com&password=password";
[urlRequest setHTTPMethod:#"POST"];
[urlRequest setHTTPBody:[params dataUsingEncoding:NSUTF8StringEncoding]];
//Create task
NSURLSessionDataTask * dataTask =[defaultSession dataTaskWithRequest: urlRequest completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
if(response!=NULL){
returnResponse =[NSString stringWithFormat:#"%#",response];
}else{
returnResponse = [NSString stringWithFormat:#"%#",error.description];
}
[self hideSpinner];
NSString* jsonString = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
[self parseJson:jsonString];
}];
[dataTask resume];
}
Ok i have changed the method now to
-(void)parseJson:(NSString*)jsonData{
NSDictionary * dictionary = [[NSDictionary alloc] initWithContentsOfFile:jsonData];
NSLog(#"%#",jsonData);
NSString* mystring = [dictionary valueForKey:#"email"];
NSLog(#"%#",mystring);
}
and here is the output i get when logging the strings
2016-01-22 00:25:48.690 testproject[627:83537] {
"api_key": "APIKEY",
"email": "example#example.com",
"password": "password",
"id": 101
}
2016-01-22 00:25:48.690 testproject[627:83537] (null)
As you can see the exception problem gone,but now i get NULL value..but you can see that just a one line above i got my son with email key string....so i have fully no clue whats going on.
valueForObject:method has nothing to do with NSDictionary. It is used by KVO which stands for Key-Value Observing. You can retrieve object from NSDictionary by using [] or objectForKey: method. Here are the examples:
dictionary[#"email"]
//or
[dictionary objectForKey:#"email"]
//EDITED
Instead of converting NSObject to NSString and trying accessing properties with KVO or dictionary methods/syntax please try to parse NSData using the code below:
NSDictionary *JSONDictionary =[NSJSONSerialization JSONObjectWithData:data options:0 error:nil]
NSString *email = JSONDictionary[#"email"];
You should be able to retrieve objects from the JSONDictionary using methods/syntax mentioned by me in the first version of the answer.
I need to use NSURLSession to make network calls. On the basis of certain things, after I receive the response, I need to return an NSError object.
I am using semaphores to make the asynchronous call behave synchronously.
The problem is, the err is set properly inside call, but as soon as semaphore ends (after
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
), the err becomes nil.
Please help
Code:
-(NSError*)loginWithEmail:(NSString*)email Password:(NSString*)password
{
NSError __block *err = NULL;
// preparing the URL of login
NSURL *Url = [NSURL URLWithString:urlString];
NSData *PostData = [Post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
// preparing the request object
NSMutableURLRequest *Request = [[NSMutableURLRequest alloc] init];
[Request setURL:Url];
[Request setHTTPMethod:#"POST"];
[Request setValue:postLength forHTTPHeaderField:#"Content-Length"];
[Request setHTTPBody:PostData];
NSMutableDictionary __block *parsedData = NULL; // holds the data after it is parsed
dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
config.TLSMinimumSupportedProtocol = kTLSProtocol11;
NSURLSession *session = [NSURLSession sessionWithConfiguration:config delegate:nil delegateQueue:nil];
NSURLSessionDataTask *task = [session dataTaskWithRequest:Request completionHandler:^(NSData *data, NSURLResponse *response1, NSError *err){
if(!data)
{
err = [NSError errorWithDomain:#"Connection Timeout" code:200 userInfo:nil];
}
else
{
NSString *formattedData = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"%#", formattedData);
if([formattedData rangeOfString:#"<!DOCTYPE"].location != NSNotFound || [formattedData rangeOfString:#"<html"].location != NSNotFound)
{
loginSuccessful = NO;
//*errorr = [NSError errorWithDomain:#"Server Issue" code:201 userInfo:nil];
err = [NSError errorWithDomain:#"Server Issue" code:201 userInfo:nil];
}
else
{
parsedData = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&err];
NSMutableDictionary *dict = [parsedData objectForKey:#"User"];
loginSuccessful = YES;
}
dispatch_semaphore_signal(semaphore);
}];
[task resume];
// but have the thread wait until the task is done
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
return err;
}
Rob's answer tells you how to do it right, but not what mistake you made:
You have two variables named err, which are totally unrelated. It seems that you haven't turned on some important warnings, otherwise your code wouldn't even have compiled.
The parameter err that is passed to your completion block is the error from the URL request. You replace it without thinking with a timeout error - so the true error is now lost. Consider that timeout is not the only error.
But all the errors that you set only set the local variable err which was passed to you in the completion block; they never touch the variable err in the caller at all.
PS. Several serious errors in your JSON handling. JSON can come in UTF-16 or UTF-32, in which case formattedData will be nil and you incorrectly print "Server Issue". If the data isn't JSON there is no guarantee that it contains DOCTYPE or html, that test is absolute rubbish. Your user with the nickname JoeSmith will hate you.
Passing NSJSONReadingAllowFragments to NSJSONSerialization is nonsense. dict is not mutable; if you try to modify it your app will crash. You don't check that the parser returned a dictionary, you don't check that there is a value for the key "User", and you don't check that the value is a dictionary. That's lots of ways how your app can crash.
I would suggest cutting the Gordian knot: You should not use semaphores to make an asynchronous method behave synchronously. Adopt asynchronous patterns, e.g. use a completion handler:
- (void)loginWithEmail:(NSString *)email password:(NSString*)password completionHandler:(void (^ __nonnull)(NSDictionary *userDictionary, NSError *error))completionHandler
{
NSString *post = ...; // build your `post` here, making sure to percent-escape userid and password if this is x-www-form-urlencoded request
NSURL *url = [NSURL URLWithString:urlString];
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:#"POST"];
// [request setValue:postLength forHTTPHeaderField:#"Content-Length"]; // not needed to set length ... this is done for you
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"]; // but it is best practice to set the `Content-Type`; use whatever `Content-Type` appropriate for your request
[request setValue:#"text/json" forHTTPHeaderField:#"Accept"]; // and it's also best practice to also inform server of what sort of response you'll accept
[request setHTTPBody:postData];
NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
config.TLSMinimumSupportedProtocol = kTLSProtocol11;
NSURLSession *session = [NSURLSession sessionWithConfiguration:config delegate:nil delegateQueue:nil];
NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *err) {
if (!data) {
dispatch_async(dispatch_get_main_queue(), ^{
completionHandler(nil, [NSError errorWithDomain:#"Connection Timeout" code:200 userInfo:nil]);
});
} else {
NSError *parseError;
NSDictionary *parsedData = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&parseError];
dispatch_async(dispatch_get_main_queue(), ^{
if (parsedData) {
NSDictionary *dict = parsedData[#"User"];
completionHandler(dict, nil);
} else {
completionHandler(nil, [NSError errorWithDomain:#"Server Issue" code:201 userInfo:nil]);
}
});
}
}];
[task resume];
}
And then call it like so:
[self loginWithEmail:userid password:password completionHandler:^(NSDictionary *userDictionary, NSError *error) {
if (error) {
// do whatever you want on error here
} else {
// successful, use `userDictionary` here
}
}];
// but don't do anything reliant on successful login here; put it inside the block above
Note:
I know you're going to object to restoring this back to asynchronous method, but it's a really bad idea to make this synchronous. First it's a horrible UX (the app will freeze and the user won't know if it's really doing something or whether it's dead) and if you're on a slow network you can have all sorts of problems (e.g. the watchdog process can kill your app if you do this at the wrong time).
So, keep this asynchronous. Ideally, show UIActivityIndicatorView before starting asynchronous login, and turn it off in the completionHandler. The completionHandler would also initiate the next step in the process (e.g. performSegueWithIdentifier).
I don't bother testing for HTML content; it is easier to just attempt parse JSON and see if it succeeds or not. You'll also capture a broader array of errors this way.
Personally, I wouldn't return my own error objects. I'd just go ahead and return the error objects the OS gave to me. That way, if the caller had to differentiate between different error codes (e.g. no connection vs server error), you could.
And if you use your own error codes, I'd suggest not varying the domain. The domain should cover a whole category of errors (e.g. perhaps one custom domain for all of your app's own internal errors), not vary from one error to another. It's not good practice to use the domain field for something like error messages. If you want something more descriptive in your NSError object, put the text of the error message inside the userInfo dictionary.
I might suggest method/variable names to conform to Cocoa naming conventions (e.g. classes start with uppercase letter, variables and method names and parameters start with lowercase letter).
There's no need to set Content-Length (that's done for you), but it is good practice to set Content-Type and Accept (though not necessary).
You need to let the compiler know that you will be modifying err. It needs some special handling to preserve that beyond the life of the block. Declare it with __block:
__block NSError *err = NULL;
See Blocks and Variables in Blocks Programming Topics for more details.
I am retrieving JSON information for an API and it says on the API that it is in JSON but I noticed it is in JSONP or "json with padding" as some call it. I tired to look everywhere to find how to parse this but no luck. The information I am trying to receive is this:
({"book":[{"book_name":"James","book_nr":"59","chapter_nr":"3","chapter":
{"16":{"verse_nr":"16","verse":"For where envying and strife is, there is confusion and
every evil work."}}}],"direction":"LTR","type":"verse"});
The link to the data is https://getbible.net/json?p=James3:16, so you can look at it directly.
This is the code I am using to try to retrieve the JSON Data and parse it into a NSMutableDictionary.
-(void)fetchJson {
NSString *currentURL = [NSString stringWithFormat:#"https://getbible.net/json?p=James"];
NSURL *url = [NSURL URLWithString:currentURL];
NSData *data = [[NSData alloc]initWithContentsOfURL:url];
NSURLRequest *theRequest = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60];
NSMutableData *receivedData = [[NSMutableData alloc] initWithLength:0];
NSURLConnection * connection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self startImmediately:YES];
[receivedData setLength:0];
NSURLResponse *response = [[NSURLResponse alloc] initWithURL:url MIMEType:#".json" expectedContentLength:-1 textEncodingName:nil];
expectedTotalSize = [response expectedContentLength];
if ([data length] !=0) {
NSLog(#"appendingData");
[receivedData appendData:data];
if(connection){
NSLog(#"Succeeded! Received %lu bytes of data",(unsigned long)[receivedData length]);
}
NSError *error;
NSDictionary *jsonResponse = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
if(jsonResponse){
NSArray *responseArr = [jsonResponse mutableCopy];
NSLog(#"%lu",(unsigned long)[responseArr count]);
}else if (!jsonResponse){
//do internet connection error response
}
}
}
The results I am getting back from putting a breakpoint in the code is:
jsonResponse returns NULL
NSError NSCocoaErrorDomain code - 3840
but my NSData *data is returning 15640 bytes.
My console is displaying this from the NSLogs I used for debugging:
2014-04-20 01:27:31.877 appendingData
2014-04-20 01:27:31.879 Succeeded! Received 15640 bytes of data
I am receiving the data correctly but I am not parsing it correctly I know the error is because the JSON is in JSONP format. If anyone could please help with this I would appreciate it so much. I have tired to give as much detail on this question as I can but if you need more information just let me know so I can add it and make this as clear as possible.
Your code has at least two separate attempts to download the data. Neither is really correct. The code also only works with JSON, not JSONP.
Try this:
NSURL *url = [NSURL URLWithString:#"https://getbible.net/json?p=James"];
NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60];
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
if (data) {
NSString *jsonString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSRange range = [jsonString rangeOfString:#"("];
range.location++;
range.length = [jsonString length] - range.location - 2; // removes parens and trailing semicolon
jsonString = [jsonString substringWithRange:range];
NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSError *jsonError = nil;
NSDictionary *jsonResponse = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&jsonError];
if (jsonResponse) {
// process jsonResponse as needed
} else {
NSLog(#"Unable to parse JSON data: %#", jsonError);
}
} else {
NSLog(#"Error loading data: %#", error);
}
}];
One problem is that the data you're downloading has extraneous information at the beginning and end. The JSON being delivered by your URL is:
({"book":[{"book_name":"James","book_nr":"59","chapter_nr":"3","chapter":{"16":{"verse_nr":"16","verse":"For where envying and strife is, there is confusion and every evil work."}}}],"direction":"LTR","type":"verse"});
As the error message you're seeing indicates: you need to remove the initial ( from the beginning of the string and the ); from the end so that your JSON will start with the dictionary that your code expects. You can do this by calling subdataWithRange: on your NSData object:
NSData* jsonData = [data subdataWithRange:NSMakeRange(1, data.length-3)];
NSDictionary* jsonResponse = [NSJSONSerialization JSONObjectWithData:jsonData
options:0
error:&error];
Just to update everyone, the NSURLRequest has been deprecated in iOS9. I tried the answer by #rmaddy, and I didn't receive anything either (just like what #lostAtSeaJoshua was encountering I guess). I have updated rmaddy's answer to reflect the NSURLSession implementation that has (I think) replaced NSURLRequest:
NSURLSession *session = [NSURLSession sharedSession];
NSURL *url = [NSURL URLWithString:#"http://somerandomwebsite.com/get.php?anotherRandomParameter=5"];
[[session dataTaskWithURL:url
completionHandler:^(NSData *data,
NSURLResponse *response,
NSError *error) {
// handle response
if (data) {
NSString *jsonString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"stringJSONed: %#",jsonString);
//Do something with the received jsonString, just like in # rmaddy's reply
} else {
NSLog(#"Error loading data: %#", error);
}
}] resume];
Just a heads up notice, when I first ran it, it gave me the security error. What you need to do (if you are using http) is to add this to your plist:
<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>
I have to mention that after the NSAllowArbitraryLoads key, there are most probably other keys and values, such as NSExceptionDomain. But they're not really relevant to this answer I think. If you need to look further, let me know and I will dig deeper :)