JSON objects from URL connection displayed in tableview - objective-c

#pragma mark -
#pragma mark Fetch loans from internet
-(void)loadData
{
self.responseData = [NSMutableData data];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:
#"http://192.168.1.104:8080/Test/ItemGroup.jsp"]];
[[NSURLConnection alloc] initWithRequest:request delegate:self];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
[connection release];
self.responseData = nil;
}
#pragma mark -
#pragma mark Process loan data
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
[connection release];
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
self.responseData = nil;
array=[responseString JSONValue];
NSMutableString *text=[NSMutableString stringWithString:#"Values:\n"];
for (int i=0; i <[array count]; i++) {
[text appendFormat:#"%#\n",[array objectAtIndex:i]];
// NSLog(#"Values:""%#\n",array);
}
}

You can use RestKit (a Cocoa RESTful web services framework) to fetch the data and use the object mapping feature to map returned data to an array of objects.
The example given in the RESTKit Object Mapping wiki maps a JSON doc into an array of Article instances: https://github.com/RestKit/RestKit/wiki/Object-mapping

Related

Set UISwitches by JSON data?

I want to set some UISwitches to values pulled in by a HTTP GET request. The request is working. However, since I'm fairly new to iOS programming I don't know how to go from having some JSON data to pulling it apart like in PHP.
This is what I currently have:
- (void)viewDidLoad
{
[super viewDidLoad];
NSLog(#"viewdidload");
self.responseData = [NSMutableData data];
NSURLRequest *request = [NSURLRequest requestWithURL:
[NSURL URLWithString:#"http://www.test.api/setings"]];
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[mutableRequest addValue:_xAuthToken forHTTPHeaderField:#"X-Auth-Token"];
request = [mutableRequest copy];
[[NSURLConnection alloc] initWithRequest:request delegate:self];
[switch1 setOn:1 animated:NO];
[switch2 setOn:1 animated:NO];
[switch3 setOn:1 animated:NO];
[switch4 setOn:1 animated:NO];
[switch5 setOn:1 animated:NO];
[switch6 setOn:1 animated:NO];
[switch7 setOn:0 animated:NO];
[switch8 setOn:1 animated:NO];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
NSLog(#"didReceiveResponse");
[self.responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[self.responseData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
NSLog(#"didFailWithError");
NSLog([NSString stringWithFormat:#"Connection failed: %#", [error description]]);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"connectionDidFinishLoading");
NSLog(#"Succeeded! Received %d bytes of data",[self.responseData length]);
// convert to JSON
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:self.responseData options:NSJSONReadingMutableLeaves error:&myError];
// show all values
for(id key in res) {
id value = [res objectForKey:key];
NSString *keyAsString = (NSString *)key;
NSString *valueAsString = (NSString *)value;
NSLog(#"key: %#", keyAsString);
NSLog(#"value: %#", valueAsString);
}
// extract specific value...
NSArray *results = [res objectForKey:#"results"];
for (NSDictionary *result in results) {
NSString *icon = [result objectForKey:#"icon"];
NSLog(#"icon: %#", icon);
}
}
- (void)viewDidUnload {
[super viewDidUnload];
}
And this is what it's getting back from the server:
{"data":
{"setting1":"1",
"setting2":"1",
"setting3":"0",
"setting4":"0",
"setting5":"0",
"setting6":"0",
"setting7":"0",
"setting8":"0"}
}
Just convert the 1 or 0 number string to bool value and then set the switch state using it
//Declare this array of switches in your class header file
property(strong,nonatomic)NSArray *switches;
and initialize it in ViewDidLoad method
switches=[NSArray arrayWithObjects:switch1,switch2,switch3,switch4,switch5,switch6,switch7,switch8,nil];
// and in your - (void)connectionDidFinishLoading:(NSURLConnection *)connection method
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:self.responseData options:NSJSONReadingMutableLeaves error:&myError];
//get the array of settings and values from the data Object in your json
NSDictionary *switchValues=[res objectForKey:#"data"];
// show all values
NSUInteger *switchIndex=0;
//iterate and convert the value to bool and set the switch state using that value
for(id key in switchValues) {
id value = [switchValues objectForKey:key];
NSString *keyAsString = (NSString *)key;
NSString *valueAsString = (NSString *)value;
[[switches objectAtIndex:switchIndex] setOn:[valueAsString boolValue] animated:NO];
NSLog(#"key: %#", keyAsString);
NSLog(#"value: %#", valueAsString);
switchIndex++;
}

Accessing FTP server from iPad using Objective C

I have this code that is trying to access an FTP using the URL. But I cant get access because it's username and password protected. How do I implement that so I can get into the server? Here is my code:
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[receivedData appendData:data];
}
- (void)connection:(NSURLConnection *)connection
didFailWithError:(NSError *)error
{
NSLog(#"Connection failed! Error - %# %#",
[error localizedDescription],
[[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// do something with the data
// receivedData is declared as a method instance elsewhere
NSLog(#"Succeeded! Received %d bytes of data",[receivedData length]);
// release the connection, and the data object
//[connection release];
//[receivedData release];
}
-(IBAction)getURL:(id)sender {
NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:#"ftp://10.0.1.***/App_Data/text.txt"]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if (theConnection) {
// Create the NSMutableData to hold the received data.
// receivedData is an instance variable declared elsewhere.
receivedData = [NSMutableData data];
} else {
// Inform the user that the connection failed.
NSLog(#"connection failed");
}}
The user id and password can be embedded in the URL:
ftp://userid:password#10.0.1.***/App_Data/text.txt

How can I receive the data by NSURLConnection in other thread in Objective-C

I write iPhone application. In this app, I use Twitter framework. In this framework, call back function made in desynchronization is in other thread.
In my view controller,
ViewController.m
[accountStore requestAccessToAccountsWithType:accountType
withCompletionHandler:^(BOOL granted, NSError *error) {
if (granted) {
if (account == nil) {
NSArray *accountArray = [accountStore accountsWithAccountType:accountType];
account = [accountArray objectAtIndex:2];
}
if (account != nil){
NSURL *url = [NSURL URLWithString:#"http://api.twitter.com/1/statuses/user_timeline.json"];
NSMutableDictionary *params = [[NSMutableDictionary alloc] init];
[params setObject:#"1" forKey:#"count"];
TWRequest *request = [[TWRequest alloc] initWithURL:url
parameters:params
requestMethod:TWRequestMethodGET];
[request setAccount:account];
[request performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
if (responseData) {
//Throw response data to other Web API
[self otherAPI:responseData];
[[NSRunLoop currentRunLoop] run];
}
}];
}
}
}];
And I write these method in this class.
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;
- (void)connectionDidFinishLoading:(NSURLConnection *)connection;
But I cannot receive full data from other API. I can receive only first data. I think there are some problems in conducting multi thread.
Therefore I'd like to let me know what's wrong in this code.
I think I see your problem. -connection:didReceiveData: is called multiple times, you need build up a NSMutableData object which will contain the whole message.
Note: This only works for a single download per instance at one time.
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
self.responseData = [[NSMutableData dataWithCapacity:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// self.responseData has all the data.
}

HTTPS request with Cocoa/objective-C

I need to make an HTTPS request from my application in order to fetch some data. I used to be able to do it using this method here
-(void)Authenticate
{
self.responseData = [NSMutableData data];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"https://10.84.4.2:8444/fish-mobile/GetPIN.jsp?MSISDN=12345"]];
//NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[[NSURLConnection alloc] initWithRequest:request delegate:self];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[responseData setLength:0];
}
- (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];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
self.responseData = nil;
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(#"%#", responseString);
}
However this is not working since I upgraded my code, my old application that has this code still works, but if I create a new application and poste this code in I get an error around
[responseData setLength:0];
and
[responseData appendData:data];
It says no visible #interface for NSString declares setLength or appenddata.
Could someone tell me why this is not working?
Thanks in advance
Shorted it to this
-(void) testme: (NSString *) link{
NSURL * url = [NSURL URLWithString:link];
NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:url];
[request addValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
[request setHTTPMethod:#"GET"];
[[NSURLConnection alloc]initWithRequest:request delegate:self startImmediately:YES];
}
And the methods are
- (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];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
NSString *s = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"%#", s);
}
Works fine
Sounds to me like your responseData instance variable is being somehow typecasted to NSString. How is the responseData ivar defined, and are you doing any other operations on it, except for the delegate ones you just posted?

How to return data directly which was loaded by NSURLConnection if delegate functions are needed?

A short explanation what I want to do: I'm using NSURLConnection to connect to a SSL webpage which is my API. The servers certificate is a self signed one so you have to accept it, for example in a web browser. I've found a solution on Stack Overflow how to do the trick (How to use NSURLConnection to connect with SSL for an untrusted cert?)
So I've added the NSURLConnection delegate to use methods like "didReceiveAuthenticationChallenge". As a result of that I cannot use this:
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:&error];
because there is no possibility to use the delegate functions in this case. My question is the following: I need a function which looks like this:
- (NSDictionary *)getData : (NSArray *)parameter {
[...|
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
[...]
return myDictionary;
}
how can I return a NSDictionary by using this? As far as you know the delegate function of NSURLConnection are called now and the response isn't available at this point. The problem is that the view controller depends on this response so I need to return the dictionary directly... Does anybody know a solution for this? What about a callback function?
okay, I've found a solution for that. A very good thing is to use blocks in objective-c.
First of all you have to add some methods to NSURLRequest and NSURL:
#implementation NSURLRequest (URLFetcher)
- (void)fetchDataWithResponseBlock:(void (^)(FetchResponse *response))block {
FetchResponse *response = [[FetchResponse alloc] initWithBlock:block];
[[NSURLConnection connectionWithRequest:self delegate:response] start];
[response release];
}
#end
#implementation NSURL (URLFetcher)
- (void)fetchDataWithResponseBlock:(void (^)(FetchResponse *response))block {
[[NSURLRequest requestWithURL:self] fetchDataWithResponseBlock:block];
}
#end
And than just implement the follwing class:
#implementation FetchResponse
- (id)initWithBlock:(void(^)(FetchResponse *response))block {
if ((self = [super init])) {
_block = [block copy];
}
return self;
}
- (NSData *)data {
return _data;
}
- (NSURLResponse *)response {
return _response;
}
- (NSError *)error {
return _error;
}
- (NSInteger)statusCode {
if ([_response isKindOfClass:[NSHTTPURLResponse class]]) return [(NSHTTPURLResponse *)_response statusCode];
return 0;
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
_response = response;
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
if (!_data) _data = [[NSMutableData alloc] init];
[_data appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
_block(self);
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
_error = error;
_block(self);
}
Now you can do the follwing, some kind of callback function:
NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"http://..."];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setValue:#"application/json" forHTTPHeaderField:#"accept"];
[request fetchDataWithResponseBlock:^(FetchResponse *response) {
if (response.error || response.statusCode != 200)
NSLog(#"Error: %#", response.error);
else {
//use response.data
}
}];
Here you can find the orginal german solution by ICNH: Asynchrones I/O mit Bloecken
Thank you very much for this!
My suggestion would be to use some other delegate methods for NSURLConnection like connection:didReceiveResponse: or connection:didReceiveData:. You should probably keep a use a set up like so:
#interface MyClass : NSObject {
…
NSMutableData *responseData;
}
…
#end
- (void)startConnection {
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:request delegate:self];
if (theConnection) {
responseData = [[NSMutableData data] retain];
} else {
// connection failed
}
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
// connection could have been redirected, reset the data
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
// connection is done, do what you want
………
// don't leak the connection or the response when you are done with them
[connection release];
[responseData release];
}
// for your authentication challenge
- (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])
if ([trustedHosts containsObject:challenge.protectionSpace.host])
[challenge.sender useCredential:[NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust] forAuthenticationChallenge:challenge];
[challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge];
}