XML answer problem - iphone

I tried to read the response data from google weather api, but german umlauts aren't shown correctly. Instead of "ö" I get "^".
I think the problem are those two lines of code:
CXMLElement *resultElement = [nodes objectAtIndex:0];
description = [[[[resultElement attributeForName:#"data"] stringValue] copy] autorelease];
How can i get data out of resultElement without stringValue?
PS: I use TouchXML to parse xml

You must be using an NSURLConnection to get your data I suppose. When you receive the data you can convert it to an NSString using appropriate encoding. E.g.
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
if(xmlResponse == nil){
xmlResponse = [[NSMutableString alloc] initWithData:data encoding:NSISOLatin1StringEncoding];
}
else{
NSMutableString *temp = [[NSMutableString alloc] initWithData:data encoding:NSISOLatin1StringEncoding];
[xmlResponse appendString:temp];
[temp release];
}
}
Here xmlResponse is the NSMutableString that you can pass to your parser. I have used NSISOLatin1 encoding. You can check other kinds of encoding and see what gives you the characters correctly (NSUTF8StringEncoding should do it I suppose).You can check the API doc for a list of supported encodings.

Related

How to Convert NSData to NSString

I know this has been asked quite before, and I already followed couple of approaches, but they don't work.
Following is what I already tried:
NSString *newStr = [NSString stringWithUTF8String:[responseData bytes]];
NSString *newStr = [NSString stringWithFormat:#"%.*s", [responseData length], [responseData bytes]];
None of them works. In 1st case, it fills newStr with null. In 2nd, it fills with junk characters. I know from debugger log (po responseData) that I get valid response which is like bbbbbb 00 bbbbbb. [server sends them as byte array]
What to do?
EDIT:
I am receiving this data from http request response - using ASIHTTPRequest library, in case anybody can help on that line.
Try this,
NSData *responseData; [Initialize it]
NSString *receivedDataString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(#"%#",receivedDataString);
Please try following code
NSString *string = [[[NSString alloc] initWithData: responseData.bytes encoding:NSUTF8StringEncoding] autorelease];
You can use this code lines
NSString *str=[[NSString alloc] initWithBytes:data1.bytes length:data1.length encoding:NSUTF8StringEncoding];
I am posting this for records sake because I found a duplicate and voting to close this down.
Actually what I am receiving is a stream of bytes represented as hex, and all the answers indicated do not work. Only [NSData description] gave me true data, which is something I can't use because it is intended for debugging.
Finally I tried the solution given here, and I get what I want.
Thanks to all for trying to help out.
NSString *image1Data = [[NSData dataWithData:myData] encodeBase64ForData];
But for this, you have to use NSData+Base64Additions class.
Use following way
NSString *dC_Str = [[NSString alloc] initWithData:decryPtd_data encoding:NSASCIIStringEncoding] ;

iphone with sbjson framework cant parse json array

Im facing some problem with json and objective c. Atm i am using sbJson framework (i can change framework if some tell me do it!) and im not being able to parse a json array.
this is the json i want to parse,
{"JsonEventosResult":
[
{"nombre":"Venta de Reposición N°13","id":34,"fecha":"16/09/2011"},
{"nombre":"evento rose","id":37,"fecha":"04/10/2011"},
{"nombre":"Prueba PhoneGap","id":40,"fecha":"23/11/2011"}
]
}
this is my code on iphone:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
[connection release];
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[responseData release];
NSError *error;
SBJSON *json = [[SBJSON new] autorelease];
NSArray *luckyNumbers = [json objectWithString:responseString error:&error];
[responseString release];
if (luckyNumbers == nil)
label.text = [NSString stringWithFormat:#"JSON parsing failed: %#", [error localizedDescription]];
else {
NSMutableString *text = [NSMutableString stringWithString:#"Lucky numbers:\n"];
for (int i = 0; i < [luckyNumbers count]; i++)
[text appendFormat:#"%#\n", [luckyNumbers objectAtIndex:i]];
label.text = text;
}
}
the error i get is that luckyNumbers is an array with 0 object.
the sample i got if from http://mobileorchard.com/tutorial-json-over-http-on-the-iphone/ .
so where is the problem? the json i get form service or the framework ?
thx
You're handling it wrong. It's not an array, it's a dictionary, the value for key #"JsonEventosResult" is the array. So In your JSON objectwithstring line, make that an nsdictionary and then point to that key
OR remove the {"JsonEventosResult": and final } so that it already is an array
Oh, and I think you'll have to Unicode escape your accented characters and degree symbol (test your JSON at jsonlint.org to make sure it's valid)

Cast JSON object (NSCFDictionary) to string and parse it

I'm working with facebook connect and trying to handle the JSON object that i'm receiving.
I invoked the requstWithGraphPath method and need to get back a JSON object,
tried to parse it and getting an error:
SBJSON *parser = [[SBJSON new] autorelease];
NSData *data = [[NSData alloc] initWithData:result];
NSString *jsonString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]; -> in this line - "[__NSCFDictionary length]: unrecognized selector sent to instance"
NSArray *events = [parser objectWithString:jsonString];
What's the problem?
Can I get the string in an other way or parse the object differently?
Thanks.
If you are working with the delegate callback
- (void)request:(FBRequest *)request didLoad:(id)result;
the parsing work has been done for you. Traverse the NSDictionary or NSArray to find the data you are looking for. If you are working with the delegate callback
- (void)request:(FBRequest *)request didLoadRawResponse:(NSData *)data;
you should initialize an NSString with the data, and use the category method that SBJSON adds to NSString for creating an id. That is assuming the data is data that constructs a string.
NSString *jsonString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
id result = [jsonString JSONValue];
Are you sure the error happens on that line, or does it happen on the line above?
If result is an NSDictionary (or CFDictionary, same thing), then it is already parsed and you do not need to do that yourself — and it could cause that error message too, on the line above.
The line:
data = [[NSData alloc] initWithData:result];
is almost certainly not what you want to do, as it is equivalent to
data = [result copy];
assuming that result is an NSData object (or NSMutableData), which I'm guessing it isn't.

iPhone encoding of non latin characters

I am trying to parse a JSON response of a GET request. When the characters, are latin no problem.
However when they are not latin the message doesn't come out correctly. I tried greek and instead of "πανος" i get "& pi; & alpha; & nu; & omicron; & sigmaf;"
The code I use for parsing the response is:
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(#"response %#", responseString);
// array from the JSON string
NSArray *results = [responseString JSONValue];
When I try to read the response from a website using ajax, everything is fine. The same applies when trying to send a GET request to the application servers with data from iphone. So when i transmit data to the server and read it from the website everything is fine. When i try to show the same data in the app, "Houston we have a problem".
Any clues?
EDIT: To avoid misunderstandings, it's not an issue of HTML, I just point out that for some readon utf-8 characters here are encoded correctly and automatically eg. "&pi" will be converted to "π", however objective c doesn't seem to do this on its own
There is a confusion I think.
π is an HTML entity which is unrelated to text encoding like UTF8 / Latin.
Read wikipedia for details about...
You need a parser to decode these entities like the one previously mentioned by Chiefly Izzy:
NSString+HTML category and method stringByReplacingHTMLEntities
Look at Cocoanetics NSString+HTML category and method stringByReplacingHTMLEntities method. You can find it at:
https://github.com/Cocoanetics/NSAttributedString-Additions-for-HTML/blob/master/Classes/NSString%2BHTML.m
Here's a pretty decent list of lot of HTML entities and their corresponding unicode characters.
Try to use this snippet of code:
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSString *decodedString = [NSString stringWithUTF8String:[responseString cStringUsingEncoding:[NSString defaultCStringEncoding]]];
NSLog(#"response %#", decodedString);
// array from the JSON string
NSArray *results = [decodedString JSONValue];
I have faced the same problem, but I solved it by changing the JSON parser. I have started using the SBJSONParser, and now I am getting the appropriate results. This is the code snippet, I have used
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:#"POST"];
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
SBJSON *parser=[[SBJSON alloc]init];
NSArray *JSONData = (NSArray*)[parser objectWithString:returnString error:nil];

How to find why NSMutableData is invalid

I access a RESTFUL url and get back results. The results are in JSON. I turn the response into a string via:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *json = [[NSString alloc] initWithBytes:[self.receivedData mutableBytes] length:[self.receivedData length] encoding:NSUTF8StringEncoding];
The json variable has a value of 0x0. When I mouse over it, I see <Invalid CFStringRef>. How can I debug this to tell why it is invalid? I render the JSON given back through the browser in A JSON parser. That checks out fine.
Results are given back by entering an ID in the URL. Other IDs return results without issue. The result set is fairly large.
First I would use initWithData:encoding: to setup the NSString. Small difference, but that method is there for a reason.
Then, I would do a hexdump of self.receivedData to see what is actually in there. If that data is not properly UTF8 encoded then the initWithData:encoding: will fail.
(Google for NSData hex dump to find other people's utility functions to do this)
I have found that sometimes web services are sloppy with their encoding. So I usually implement a fallback like this:
NSString* html = [[NSString alloc] initWithData: data encoding: NSUTF8StringEncoding];
if (html == nil) {
html = [[NSString alloc] initWithData: data encoding: NSISOLatin1StringEncoding];
if (html == nil) {
html = [[NSString alloc] initWithData: data encoding: NSMacOSRomanStringEncoding];
}
}
It is kind of sad that this is required but many web services are not written or configured properly.
Use NSLog to look at the bytes.