There are, for example, 100 JSON files and appropriate 100 images on my ftp server.
1.With loading JSON where are no bug (I hope)
NSString *recipesPath = #"ftp://.../recipes/";
NSString *recipeFileName = [NSString stringWithFormat:#"00001.json", recipeCode];
NSString *recipeFileFullPath = [recipesPath stringByAppendingString:recipeFileName];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:recipeFileFullPath]];
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSError *error = nil;
NSDictionary *recipeDictionary = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
2.But images can not be loaded
NSString *recipeImageName = #"recipeImages/00001-1.jpg";
NSString *recipeImageFullPath = [recipesPath stringByAppendingString:recipeImageName];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:recipeImageFullPath]];
if (request) {
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
if (responseData) {
UIImage *image = [UIImage imageWithData:responseData];
}
}
responseData nearly always is nil.
May be there is the other method?
All this code is in MyMethod which I execute in NSOperationQueue:
operation = [[NSInvocationOperation alloc] initWithTarget:self selector:#selector(MyMethod) object:nil];
[operationQueue addOperation:operation];
EDIT: image sizes are not big - from 50 to 100 kbyte
EDIT: can image file extension affect to downloading process?
You can try this:
NSURL *url = [NSURL URLWithString:recipeImageFullPath];
NSData *data = [NSData alloc] initWithContentsOfURL:url];
Please try to test it:
NSError *requestError;
NSURLResponse *urlResponse = nil;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&requestError];
/* Return Value
The downloaded data for the URL request. Returns nil if a connection could not be created or if the download fails.
*/
if (responseData == nil) {
// Check for problems
if (requestError != nil) {
...
}
}
else {
// Data was received.. continue processing
}
Related
I'm new to Objective-C, just wondering how to use NSArray object outside from JSON.
For example:
NSURL *url = [NSURL URLWithString:#"http://acumen-locdef.elasticbeanstalk.com/service/countries"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSMutableArray *myFinalListArray = [[NSMutableArray alloc] init];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response,
NSData *data, NSError *connectionError)
{
if (data.length > 0 && connectionError == nil)
{
NSMutableArray *greeting = [NSJSONSerialization JSONObjectWithData:data
options:0
error:NULL];
for (NSDictionary *countryList in greeting) {
[myFinalListArray addObject:countryList[#"name"]];
}
}
NSLog(#"%#",myFinalListArray); //(This one showing all results..)
}];
NSLog(#"%#",myFinalListArray); //(This one giving empty result)
I have defined myFinalListArray and added objects in for loop.
If you use NSLog inside the loop or outside the loop it will show you results. But if I use this after }]; (after the code is ending.),
it's giving me empty array.
If you are accessing myFinalListArray in tableview then you can reload tableview inside the block after fetching data.
Or if you are accessing this array in some other task then you have to make notification call (have to add observer) and then post notification that will call some other method and access your array there and do your further stuff.
The block of code associated with sendAsynchronousRequest isn't executed until the network fetch has completed; this takes some time. While the network fetch is happening your code continues to execute, starting with the line immediately after sendAsynchronousRequest which is NSLog(#"%#",myFinalListArray); - but because the network operation hasn't completed you get an empty array.
In the block you need to include the code that you need to process the array, update your user interface or whatever (If you update UI make sure you dispatch the operation on the main thread)
This will work. You can try with this.
- (void)viewDidLoad {
[super viewDidLoad];
NSMutableArray *myFinalListArray = [[NSMutableArray alloc] init];
//Pass here the reference the a array. It will return you the array of you county when downloaded complete.
[self getURLResponse:&myFinalListArray];
NSLog(#"countryArray:%#",myFinalListArray);
}
-(void)getURLResponse:(NSMutableArray**)countryArray{
NSURL *url = [NSURL URLWithString:#"http://acumen-locdef.elasticbeanstalk.com/service/countries"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSMutableArray *myFinalListArray = [[NSMutableArray alloc] init];
NSURLResponse *response;
NSError *error = nil;
NSData *data = [NSURLConnection sendSynchronousRequest:
request returningResponse:&response error:&error];
NSMutableArray *greeting = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
for (NSDictionary *countryList in greeting) {
[myFinalListArray addObject:countryList[#"name"]];
}
*countryArray = [[NSMutableArray alloc]initWithArray:myFinalListArray copyItems:YES];
}
-(void)sendRequest
{
NSURL *url = [NSURL URLWithString:#"http://acumen-locdef.elasticbeanstalk.com/service/countries"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSMutableArray *myFinalListArray = [[NSMutableArray alloc] init];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response,
NSData *data, NSError *connectionError) {
if (data.length > 0 && connectionError == nil)
{
NSMutableArray *greeting = [NSJSONSerialization JSONObjectWithData:data
options:0
error:NULL];
if( !myFinalListArray )
{
myFinalListArray=[[NSMutableArray alloc]init];
}
for (NSDictionary *countryList in greeting) {
[myFinalListArray addObject:countryList[#"name"]];
}
}
[self printArray];
}];
}
//create method that will execute after response
-(void) printArray
{
NSLog(#"%#",myFinalListArray); //(This one showing all results..)
}
Use
__block NSMutableArray *myFinalListArray = [[NSMutableArray alloc] init];
This should work.
Happy Coding.
sendAsynchronousRequest runs asynchronously, meaning that the code below is already performed while the request is still running, so the NSLog is logging the empty array.
Only when the request finishes, the array is filled up but your outer NSLog was already performed.
NSString *urlString=[NSString stringWithFormat:#"http://192.168.178.1/iBus/appService/_getMarker.php"];
NSURL *url = [NSURL URLWithString:urlString];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSError *error = [[NSError alloc] init];
NSHTTPURLResponse *responseCode = nil;
NSData *dataConnect;
dataConnect = [NSURLConnection sendSynchronousRequest:request returningResponse:&responseCode error:&error];//connect todata
NSDictionary * jsonObj;
if (responseCode) {//if connect(response)
NSLog(#"%#",dataConnect);//here is return data
NSLog(#"%#",[NSJSONSerialization JSONObjectWithData:dataConnect options:kNilOptions error:nil]);//here is return NULL!!!
}
Its return NSData but not encode to JSON
Here is slog console
2014-12-18 13:14:00.997 iBus[2689:58536] (null)
Here is my json output : http://notes.io/Zd3
According to the documentation, if JSONObjectWithData returns nil, that means an error occurs. You can read the error message by passing a reference to an NSError object to the error: argument.
As Kampai mentioned, this is likely caused by invalid JSON.
**In this code When add breakpoint from viewdidload( ) function then i got greetingArray.count zero but when i add breakpoint at the for loop then it works properly and i got the results 3 as the values of the greetingArray. What is the possible reason that no getting the data from server.There is no problem with server side.I already check for it.
- (void)viewDidLoad
{
[super viewDidLoad];
greetingArray = [[NSMutableArray alloc] init];
greetingDictionary = [[NSMutableDictionary alloc] init];
NSString *connectionString;
connectionString=[NSString stringWithFormat:#"http://xxx.xxx.x.xx/TestMgt/api/%#",self.fieldName];
NSURL *url = [NSURL URLWithString:connectionString];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response,
NSData *data, NSError *connectionError)
{
if (data.length > 0 && connectionError == nil)
{
NSLog(#"----------------------------------------------------");
NSLog(#"Data length is = %d",data.length);
greetingMArray = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
NSLog(#"%#",greetingMArray);
for(int i = 0 ; i< greetingMArray.count; i++)
{
greetingDictionary = (NSMutableDictionary *)[greetingMArray objectAtIndex:i];
NSLog(#"%#",greetingDictionary);
ConnectionOvertime *overtime = [[ConnectionOvertime alloc] init];
overtime.entryDate=[greetingDictionary valueForKey:#"EntryDate"];
[greetingArray addObject:overtime];
NSLog(#"%d",greetingArray.count);
}
}
}];
}
if you don't get any answer try jsonFramework library and import sbjsonParser.h
for Example try below code
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
self.ChapterID=[[NSMutableArray alloc]init];
self.ChapterName=[[NSMutableArray alloc]init];
NSURL *url=[NSURL URLWithString:#"https://www.coursekart.com/webservice/load-subjects.php?api_key=68410920GHJFLAC878&standard_id=2&format=json"];
NSURLRequest *request=[[NSURLRequest alloc]initWithURL:url];
NSError *error;
NSURLResponse *response;
NSData *data=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if(data!=nil)
{
NSString *content=[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
if(content.length!=0)
{
SBJsonParser *parser=[[SBJsonParser alloc]init];
NSArray *dir=[[parser objectWithString:content]objectForKey:#"SubjectList"];
for(int i=0;i<dir.count;i++)
{
NSDictionary *array=[dir objectAtIndex:i];
NSArray *data=[array objectForKey:#"Data"];
NSDictionary *dat=(NSDictionary *)data;
NSString *idCh=[dat objectForKey:#"id"];
NSString *slug=[dat objectForKey:#"slug"];
[ChapterID addObject:idCh];
[ChapterName addObject:slug];
// NSLog(#"%#",[ChapterID objectAtIndex:0]);
//NSLog(#"%#",[ChapterName objectAtIndex:0]);
}
}
}
}
I'm working on an iPad app that requests data from a server, changes and submits it, and then re-requests the data from the server, displaying it to the user. The app updates the data just fine (the equivalent web app sees the update happening), but the data that the iPad app gets back is the old data. I thought maybe it was the caching flag on the NSURLRequest, but it doesn't look like it.
Here is my sequence of calls:
NSString* currentStuff = self.fCurrentIndex.currentStuff;
NSError* err = nil;
[self.fCurrentIndex approve:currentStuff withUsername:username andPassword:password error:&err];
if (err == nil)
{
// rebuild the case list (grab the data from the URL again first)
[self getCaseListViaURL]; // grab the updated data
[self setupUIPanel]; // display it
}
Here's the code that grabs the data (the 'getCaseListViaURL' call):
NSURLResponse* response;
NSError* err = nil;
NSMutableDictionary * jsonObject = nil;
NSString * urlRequestString;
urlRequestString = [method to get the URL string];
NSURL * url = [NSURL URLWithString:urlRequestString];
NSURLRequest * request = [NSURLRequest requestWithURL:url
cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
timeoutInterval:60];
NSData * data = [NSURLConnection sendSynchronousRequest:request
returningResponse:&response
error:&err];
if (err == nil)
{
jsonObject = [NSJSONSerialization JSONObjectWithData:data
options:NSJSONReadingMutableContainers
error:&err];
}
if (err && error) {
*error = err;
}
return jsonObject;
Is there any way to force the server to serve up the updated data?
Thanks in advance.
EDIT: Per comments, I'm adding the sequence of update to the server and subsequent pull:
This does the push to the server:
NSString* currentStuff = self.fCurrentIndex.currentStuff;
NSError* err = nil;
[self.fCurrentPatient approveStuff:currentStuff withUsername:username andPassword:password error:&err];
Where 'approveStuff' eventually calls:
__block NSData * jsonData;
__autoreleasing NSError * localError = nil;
if (!error) {
error = &localError;
}
// Serialize the dictionary into JSON
jsonData = [NSJSONSerialization dataWithJSONObject:data
options:NSJSONWritingPrettyPrinted
error:error];
if (*error) return nil;
NSURLResponse* response;
NSString * urlRequestString;
urlRequestString = [self urlStringForRelativeURL:relativeURL
withQueryParams:params];
NSURL * url = [NSURL URLWithString:urlRequestString];
NSMutableURLRequest * request;
request = [NSMutableURLRequest requestWithURL:url
cachePolicy:self.cachePolicy
timeoutInterval:self.timeOutInterval];
[request setHTTPMethod:#"POST"];
[request setHTTPBody:jsonData];
[request setValue:#"application/json;charset=UTF-8" forHTTPHeaderField:#"Content-Type"];
jsonData = [NSURLConnection sendSynchronousRequest:request
returningResponse:&response
error:&localError];
NSMutableDictionary * jsonObject;
if (localError == nil)
{
jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData
options:NSJSONReadingMutableContainers
error:&localError];
}
if (error && localError) {
*error = localError;
}
return jsonObject;
Right after this, I call the aforementioned get call and rebuild the UI. Now, if I stick a breakpoint when I do the get, and check on the web server if the data is updated after the push, I see the data is there. However, when I let the get operation continue, it gives me the old data.
So it looks like the issue was on the server. There were some data structures on the server side that weren't being refreshed when the data was being posted.
Where JSON_CATEGORY_DATA_URL_STRING is my feed URL, which returns fine as:
[
{
"group":"For Sale",
"code":"SSSS"
},
{
"group":"For Sale",
"category":"Wanted",
"code":"SWNT"
}
]
I cannot seem to get a nice NSDictionary (or NSArray) out of the following code:
+ (NSDictionary *)downloadJSON
{
NSDictionary *json_string;
NSString *dataURL = [NSString stringWithFormat:#"%#", JSON_CATEGORY_DATA_URL_STRING];
NSLog(#"%#",dataURL);
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:dataURL]];
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
json_string = [[[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding]autorelease];
NSDictionary *json_dict = (NSDictionary *)json_string;
NSLog(#"json_dict\n%#",json_dict);
NSLog(#"json_string\n%#",json_string);
return json_string;
}
I've read many posts on this, but am not getting it.
With IOS5 you can use NSJSONSerialization for serializing the JSON.
NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
You can't just cast a string as a dictionary and expect it to parse the JSON. You must use a JSON parsing library to take that string and convert it into a dictionary.
I made a class that makes this task easier. It uses iOS 5's NSJSONSerialization. Clone it from github here.
You need to use JSON parser. here is the edited code
+ (NSDictionary *)downloadJSON
{
NSDictionary *json_string;
NSString *dataURL = [NSString stringWithFormat:#"%#", JSON_CATEGORY_DATA_URL_STRING];
NSLog(#"%#",dataURL);
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:dataURL]];
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
json_string = [[[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding]autorelease];
//JSONValue is a function that will return the appropriate object like dictionary or array depending on your json string.
NSDictionary *json_dict = [json_string JSONValue];
NSLog(#"json_dict\n%#",json_dict);
NSLog(#"json_string\n%#",json_string);
return json_dict;
}
this should be the code to get the NSDictionary. but you json string is an array so instead use .
+ (NSArray *)downloadJSON
{
NSDictionary *json_string;
NSString *dataURL = [NSString stringWithFormat:#"%#", JSON_CATEGORY_DATA_URL_STRING];
NSLog(#"%#",dataURL);
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:dataURL]];
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
json_string = [[[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding]autorelease];
NSArray *json_dict = [json_string JSONValue];
NSLog(#"json_dict\n%#",json_dict);
NSLog(#"json_string\n%#",json_string);
return json_dict;
}
Edit:
you need to use JSON.framework to call JSONValue method.
also you need to return json_dict instead of json_string as json_string is of NSString type and not NSDictionary or NSArray.
and dont autorelease it, as it is your class variable
create method to fetchjson data.Pass your url in urlwithstring.
-(void)fetchjsondata
{
NSString *login= [[NSString stringWithFormat:#"your url string"]stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(#"----%#", login);
NSURL *url = [NSURL URLWithString:[login stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
//-- Get request and response though URL
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
dispatch_async(dispatch_get_main_queue(), ^{
if (data) {
dic_property= [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
NSLog(#"%#", dic_property);
NSLog(#"counts=%d",[[dic_property objectForKey:#"Data"]count]);
}
else {
NSLog(#"network error, %#", [error localizedFailureReason]);
}
});
}];
}
call fetchjsonmethod in anywhere.
[NSThread detachNewThreadSelector:#selector(fetchdata) toTarget:self withObject:nil];