Fast Enumeration in parse - json

I'm new to iOS and I'm trying to parse out JSON data. Nothing will log from inside of the enumeration, though vehicleActivity logs "vehicle (null).I am interested in logging the "LineRef" data. I'm assuming it is in NSString, but I tried with id object and still nothing.
NSDictionary *jsonParse = [NSJSONSerialization JSONObjectWithData:webData options:0 error:nil];
NSArray * vehicleActivity = [jsonParse objectForKey:#"VechicleActivity"];
NSLog(#"vehicle %#",vehicleActivity);
for (NSDictionary *dictionary in vehicleActivity ) {
NSDictionary *monitoredVehJourney = [dictionary objectForKey:#"MonitoredVehicleJourney"];
NSString *line = [monitoredVehJourney objectForKey:#"LineRef"];
NSLog(#"Line # %#",line);
Here is the JSON through a viewer
Thanks

though vehicleActivity logs "vehicle (null)"
That's why. If vehicleActivity is NULL (i. e., nil), then the fast enumeration wouldn't even begin.
Furthermore, you seem not to have read the documentation of the NSDictionary class. It iterates through keys, not values. So your for loop should be
for (NSString *key in vehicleActivity ) {
NSDictionary *dictionary = [vehicleActivity objectForKey:key];
// etc.
}
instead.
Furthermore, I believe you have a typo in your code regarding the key VehicleActivity. You wrote it as VechicleActivity.

Related

NSJSONSerialization not handling negative integers

I’m trying to parse an JSON file into an NSArray and it all works well for positive numbers. However all the negative integers in that JSON file produce high numbers like “[11] __NSCFNumber * (long)72057594037927933”. How can i get that to work?
Here is my JSON file:
[0,1,2,3,4,5,6,7,8,9,10,-2,-3,-4,-5,-6,-7,-8,-9,-10,-11]
and here the code:
NSError* error;
NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:#"https://some/json/file.json"]];
NSMutableArray* array = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
Xcode doesn't always print nice values into the Debug area of the Xcode (where live values for the context appear).
I dropped your code into my own project and when I step through each line, I do see the "eachNumber __NSCFNumber * (long)72057594037927934 {0xbfffffffffffffe3} bits, but if I try print out the values of the array into the console, you'll see the correct "-2" result.
Try it yourself. I added in these lines right after yours:
NSMutableArray* array = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
NSLog(#"array is %#", array);
for(id eachNumber in array)
{
NSLog(#"eachNumber is %#", eachNumber);
}

Converting NSString to NSData for use in XCODE

I am getting data from the Yummly API and I would like to use it as though it were serialized JSON data. However, it is currently a string, and I cannot figure out how to turn it to data correctly. The code is as following:
NSString *searchParameters = #"basil"; //should be from text box
//NSError *error1 = nil;
NSString *searchURLName = [#"http://api.yummly.com/v1/api/recipes?_app_id=myAPIId&_app_key=myAPIkey&" stringByAppendingString:searchParameters];
NSURL *searchURL = [NSURL URLWithString:searchURLName];
NSString *searchResults = [NSString stringWithContentsOfURL:searchURL encoding:NSUTF8StringEncoding error:nil];
// Here, the search results are formatted just like a normal JSON file,
// For example:
/* [
"totalMatchCount":777306,
"facetCounts":{}
]
*/
// however it is a string, so I tried to convert it to data
NSData *URLData = [searchResults dataUsingEncoding:NSUTF8StringEncoding];
URLData = [URLData subdataWithRange:NSMakeRange(0, [URLData length] - 1)];
_searchArray = [NSJSONSerialization JSONObjectWithData:URLData options:NSJSONReadingMutableContainers error:nil];
Somewhere over the last four lines, it didn't do what it was supposed to and there is no data in the data object. Any advice or quick hints in the right direction are much appreciated! Thank you1
Look at the error being returned from the NSJSONSerialization object like
NSError *error;
_searchArray = [NSJSONSerialization JSONObjectWithData:URLData options:NSJSONReadingMutableContainers error:&error];
NSLog(#"%#", error);
This might give you a hint of what's wrong. This should work though.
And why exactly are you doing URLData = [URLData subdataWithRange:NSMakeRange(0, [URLData length] - 1)];? You don't need to copy the data, if that's why you're doing that.
Plus, it seems like you're assuming to get an array as the top level object (judging by
/* [
"totalMatchCount":777306,
"facetCounts":{}
]
*/
but this is a dictionary. Basically you probably want a dictionary, not array. This it should be
/* {
"totalMatchCount":777306,
"facetCounts":{}
}
*/
But the error getting returned will tell you that.
It looks like you're over-complicating things a bit. You do not need to bring in this data as an NSString at all. Instead, just bring it in as NSData and hand that to the parser.
Try:
NSString *searchParameters = #"basil"; //should be from text box
NSString *searchURLName = [#"http://api.yummly.com/v1/api/recipes?_app_id=myAPIId&_app_key=myAPIkey&" stringByAppendingString:searchParameters];
NSURL *searchURL = [NSURL URLWithString:searchURLName];
NSData *URLData = [NSData dataWithContentsOfURL:searchURL];
_searchArray = [NSJSONSerialization JSONObjectWithData:URLData options:NSJSONReadingMutableContainers error:nil];
Note that you'll want to verify that the parsed JSON object is indeed an array as expected, and is not/does not contain [NSNull null].

iOS Parsing JSON Woes

I've been bashing my head against a wall for a bit.
I have a rails back-end that is returning JSON to my iOS app. I'm using rails' default return for rendering my object in JSON for me automatically. I'm having trouble with the errors it returns.
The JSON I get for errors is {"errors":{"email":["can't be blank"],"password":["can't be blank"]}}.
I use ASI for handling the request.
-(void) requestFinished:(ASIFormDataRequest *)request {
NSDictionary *data = [[request responseString] JSONValue];
Doing the above code make data become:
{
errors =
{
email = (
"can't be blank"
);
password = (
"can't be blank"
);
};
}
Now this gives me issues trying to parse it out. I'd like to be able to access each element of errors, and its associated value.
When I try to loop through the elements, I do something like:
for (NSDictionary *error in [data objectForKey:#"errors"])
This will give me email and password, but they are of type __NSCFString, not NSDictionary. I haven't been able to find a way to get the value for either email or password. Does anyone have an idea on how to parse this out?
Thanks!
This should work, note that response has the same structure than your 'data' NSDictionary.
NSDictionary *fields = [[NSDictionary alloc] initWithObjectsAndKeys: [[NSArray alloc] initWithObjects:#"one", #"two", nil],
#"A",
[[NSArray alloc] initWithObjects:#"three", #"four", nil],
#"B",
nil];
NSDictionary *response = [[NSDictionary alloc] initWithObjectsAndKeys:fields, #"errors", nil];
NSLog(#"Dictionary: %#", [response objectForKey:#"errors"]);
for (NSString *field in [response objectForKey:#"errors"])
for (NSString* error in [response valueForKeyPath:[NSString stringWithFormat:#"errors.%#", field]])
NSLog(#"%# %#", field, error);
The output will look like this:
Dictionary: {
A = (
one,
two
);
B = (
three,
four
);
}
A one
A two
B three
B four
Well i dont have Mac right now but i'm trying to help you if it doesnt work let me know i will correct it tomorrow.
-(void) requestFinished:(ASIFormDataRequest *)request
{
NSArray *data = [[request responseString] JSONValue];
NSDictionary *dict = [data objectAtIndex:0];
NSDictionary *dict2 = [dict valueForKey:#"errors"];
NSLog(#"email = %#, password = %#",[dict2 valueForKey:#"email"], [dict2 valueForKey:#"password"]);
}

I use JSON but there is exception [NSString objectForKey:]

i read information in my database i use JSON but there is exception
'NSInvalidArgumentException', reason: '-[NSCFString objectForKey:]: unrecognized selector sent to instance 0x603dfb0'
I think this part :
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *str = [[[NSString alloc] initWithData:buffer encoding:NSUTF8StringEncoding] autorelease];
NSArray *array = [str JSONValue];
if (!array)
return;
NSDateFormatter *fmt = [[[NSDateFormatter alloc] init] autorelease];
[fmt setDateFormat:#"yyyy-MM-dd"];
for (NSDictionary *dict in array) {
NSDate *d = [fmt dateFromString:[dict objectForKey:#"eve_date"]];
NSLog(#"%#",d);
[eventPHP addObject:[Events eventsNamed:[dict objectForKey:#"title_event"] description:[dict objectForKey:#"description"] date:d]];
}
}
"pass the linker a special flag, ‘-ObjC’. Adjusting the build settings of my project to include this flag in the ‘Other linker flags’"
according to:
http://beatworm.co.uk/blog/computers/using-categories-on-objective-c-classes-in-a-static-library/
EDIT:
Why it is terminating?
EDIT2:
OK, not exactly sure (as I've never done this type of coding), but given the json data:
{"event":[
{"eve_date":"2011-12-18","eve_time":"00:00:06","title_event":"Google event","description":"Google event for IT student"},
{"eve_date":"2011-12-29","eve_time":"00:00:08","title_event":"microsoft event","description":"microsoft event for IT student"}
]}
The first object is an array labeled "event" which might be throwing you off.
So, try replacing this:
for (NSDictionary *dict in array) {
NSDate *d = [fmt dateFromString:[dict objectForKey:#"eve_date"]];
NSLog(#"%#",d);
[eventPHP addObject:[Events eventsNamed:[dict objectForKey:#"title_event"] description:[dict objectForKey:#"description"] date:d]];
}
with:
NSArray *array2 = [array objectForKey:#"event"];
for (NSDictionary *dict in array2) {
NSDate *d = [fmt dateFromString:[dict objectForKey:#"eve_date"]];
NSLog(#"%#",d);
[eventPHP addObject:[Events eventsNamed:[dict objectForKey:#"title_event"] description:[dict objectForKey:#"description"] date:d]];
}
using: Problem getting JSON contents with JSONValue
Not sure if that will work, but if it does, it will make more sense to me.
I solve exception by change location files class of JSON but the event doesn't
display in calendar .
the calendr is display but didn't contain any event
hint: when i put url in browser the content of database display

How to extract app information from the Apple store?

I'm a newbie with Json, so I want to extract some app information from the app store, I found this question here :
How to get info from the Apple iTunes «App Store» and «Mac App Store»
It allows to get a Json file containing all the app information, but it would be nice if someone could show me how to get the price for example.
Thanks.
Where and how do you want to collect the results? Is this for an app or for some other kind of tool? In the reuslting JSON you have an array "results" where each element has a "currency" and a "price" value. Those can be queired rather simply. For example using the iOS 5 NSJSONSerialization (note this is an example, there has to be more error handling, handling of no / too many entries etc):
// assuming you have the downloaded data
NSError *error = nil;
NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:downloadedData options:nil error:&error];
if (error != nil)
{
// error handling
}
else
{
NSArray *results = [jsonData objectForKey:#"results"];
// assuming you have 1 valid entry
NSDictionary *result = [results objectAtIndex:0];
NSNumber *price = [result objectForKey:#"price"];
NSString *currency = [result objectForKey:#"currency"];
NSLog(#"Price is %# #%", price, currency);
}
Similar ways to access the data are avilable in other JSON frameworks, just grad the results array and every dictionary therein has a price and currency value.