Saving JSON file to iPhone - ios

Question

I want save json file from server each time, when user have internet connection to use it when iPhone doesnt have internet connection. But it doesn't working. Here is my code:
- (void)writeJsonToFile
{
//applications Documents dirctory path
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//live json data url
NSString *stringURL = #"http://volodko.info/ic/json.php";
NSURL *url = [NSURL URLWithString:stringURL];
NSData *urlData = [NSData dataWithContentsOfURL:url];
//attempt to download live data
if (urlData)
{
NSString *filePath = [NSString stringWithFormat:#"%#/%#", documentsDirectory,#"data.json"];
[urlData writeToFile:filePath atomically:YES];
}
//copy data from initial package into the applications Documents folder
else
{
//file to write to
NSString *filePath = [NSString stringWithFormat:#"%#/%#", documentsDirectory,#"data.json"];
//file to copy from
NSString *json = [ [NSBundle mainBundle] pathForResource:#"data" ofType:#"json" inDirectory:#"html/data" ];
NSData *jsonData = [NSData dataWithContentsOfFile:json options:kNilOptions error:nil];
//write file to device
[jsonData writeToFile:filePath atomically:YES];
}
}

Answer 1

try this . . .
- (void)writeJsonToFile
{
//applications Documents dirctory path
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//live json data url
NSString *stringURL = #"http://volodko.info/ic/json.php";
NSURL *url = [NSURL URLWithString:stringURL];
NSData *urlData = [NSData dataWithContentsOfURL:url];
//attempt to download live data
if (urlData)
{
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"data.json"];
[urlData writeToFile:filePath atomically:YES];
}
//copy data from initial package into the applications Documents folder
else
{
//file to write to
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"data.json"];;
//file to copy from
NSString *json = [ [NSBundle mainBundle] pathForResource:#"data" ofType:#"json" inDirectory:#"html/data" ];
NSData *jsonData = [NSData dataWithContentsOfFile:json options:kNilOptions error:nil];
//write file to device
[jsonData writeToFile:filePath atomically:YES];
}
}

Answer 2

This works for me. Read the AFJSONRequestOperation guide. The code also checks if the json-file already have been cached.
NSString *path = #"http://volodko.info/ic/json.php";
NSURL *url = [[NSURL alloc] initWithString:path];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
id cachedJson = [[NSUserDefaults standardUserDefaults] valueForKey:path];
if (cachedJson) {
[self didUpdateJSON:cachedJson];
} else {
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
[self didUpdateJSON:JSON];
dispatch_async(dispatch_get_main_queue(), ^{
[[NSUserDefaults standardUserDefaults] setObject:JSON forKey:path];
[[NSUserDefaults standardUserDefaults] synchronize];
});
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
NSLog(#"Request Failed with Error: %#, %#", error, error.userInfo);
}];
[operation start];
}

Answer 3

Fetch data from JSON parser and store it in an array. After that you can add it to a SQLite database.

Answer 4

You should create path in proper way
replace this
NSString *filePath = [NSString stringWithFormat:#"%#/%#", documentsDirectory,#"data.json"];
with
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"data.json"];

Answer 5

Anton , fetch the json data and store in the nsmutable array at the first time you Array hold the data when u run again ur array not a nil but replay the data to the second time ... and another way to store the data in local database...if u r needed to store the data..
but ur problem is solve for first one..ok best of luck..

Answer 6

Try using NSUserDefaults instead of writing this small JSON text to a file
- (void)writeJsonToFile
{
NSString *jsonString;
NSString *stringURL = #"http://volodko.info/ic/json.php";
NSURL *url = [NSURL URLWithString:stringURL];
NSData *urlData = [NSData dataWithContentsOfURL:url];
if (urlData)
{
// JSON successfully downloaded, store it to user defaults
jsonString = [[NSString alloc] initWithData:urlData encoding:NSUTF8StringEncoding];
[[NSUserDefaults standardUserDefaults] setValue:jsonString forKey:#"jsonString"];
}
else
{
// no urlData, using stored JSON
jsonString = [[NSUserDefaults standardUserDefaults] valueForKey:#"jsonString"];
}
}
possibly even better:
- (NSString *)getJSON
{
<the code above>
return jsonString;
}
and then use it in other functions as:
NSString *jsonString = [self getJSON];