i have Used NSMutableData to merge byte arrays
NSMutableData *payload;
payload = [[NSMutableData alloc] init];
[payload appendBytes:CFBridgingRetain((cm.msgBytes)) length:[cm.msgBytes length]];
NSString *cmdata = [[NSString alloc] initWithData:[payload mutableBytes] encoding:NSUTF8StringEncoding];
i want to keep on adding to payload until done
cmdata is always nil
as initWithData takes NSData so i converted the bytes to NSData but the result is still same
NSData *bytesData = [NSData dataWithBytes:[payload mutableBytes] length:[payload length]];
NSString *cmdata = [[NSString alloc] initWithData:bytesData encoding:NSUTF8StringEncoding];
I think you're confusing things in several places. Where an API says "bytes", it's talking about a C array of bytes; where it says "data", it's talking about an NSData object.
Assuming cm.msgBytes is an NSData object, which it appears to be given that you retrieve its .length, a better version of this code would be:
NSMutableData *payload;
payload = [[NSMutableData alloc] init];
[payload appendData:cm.msgBytes];
NSString *cmdata = [[NSString alloc] initWithData:payload encoding:NSUTF8StringEncoding];
If you wrote the class cm belongs to, you should probably rename msgBytes to msgData (or even messageData), to match the APIs better.
initWithData takes an NSData not bytes itself
NSString *cmdata = [[NSString alloc] initWithData:payload encoding:NSUTF8StringEncoding];
Related
I'm trying to make an xcode plugin that needs to write something to the .h file from the .m file. I haven't been able to find a stackoverflow post with an answer on how to do this. I've tried this code
NSData *data = [NSData dataWithContentsOfFile:filePath];
NSString *contents = [[NSString alloc] initWithBytes:[data bytes] length:[data length] encoding:NSUTF8StringEncoding];
I've also tried using the StringWithContentsOfFile method, however they both return nil. Is it because you can't read an .h file with this code or is it something else I'm missing.
filePath is this and it's a correct filepath, my ftp client can read it atleast file:///Users/myUserName/Documents/code/macOsDev/XcodePlugIns/XcoderPlugin/XcoderPlugin/XcoderPlugin.h
So my question is, how do I read and write to a .h file? Thanks in advance.
EDIT as requested, some more code however this is as far as I've gotten to the read/write part of my plugin.
NSString *filePath = path;
NSData *data = [NSData dataWithContentsOfFile:filePath];
NSString *contents = [[NSString alloc] initWithBytes:[data bytes] length:[data length] encoding:NSUTF8StringEncoding];
NSError *error;
NSString *contents1 = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:&error];
contents is #"" because data is nil
and contents1 is just nil;
error is error
NSError * domain: #"NSCocoaErrorDomain" - code: 260
in the debugger, but I'm not sure I'm using this error thing correctly.
Use "/Users/myUserName/Documents/code/macOsDev/XcodePlugIns/XcoderPlugin/XcoderPlugin/XcoderPlugin.h".
Dont use 'file://' prefix
Following is the code for reading and writing
NSString *path = #"your/path/tp/.h/file";
NSData *data = [NSData dataWithContentsOfFile:path];
//Get the contents of the file into the mutable string
NSMutableString *contents = [[NSMutableString alloc] initWithBytes:[data bytes] length:[data length] encoding:NSUTF8StringEncoding];
//Make changes to your mutable string
[contents appendString:#"abc"];
//Write it back to the file
[contents writeToFile:path atomically:YES encoding:NSUTF8StringEncoding error:nil];
I packed an object (NSObject) to (NSData) and then encoded it with (NSASCIIStringEncoding) for sending it to a SQLite database with this code:
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:canvasView.trazoYorch];
//convert NSData object to plain text for sending it to DB
NSData *data2 = [[NSString stringWithFormat:#"%#",data] dataUsingEncoding:NSASCIIStringEncoding];
NSString *dataStr = [[NSString alloc] initWithData:data2 encoding:NSASCIIStringEncoding];
everything works ok, but when I want to do the Inverse process NSString to NSData I got different results, this is my code for inverse process
NSString *FirmaString = [self traerFirmadeBD]; //returns the string content of DB
NSData *data2 = [FirmaString dataUsingEncoding:NSASCIIStringEncoding];
FirmaYorch *firmaCompleta = [NSKeyedUnarchiver unarchiveObjectWithData:data2];
Any help solving this I will appreciate
I found this method to convert an NSData to an NSString object.
NSData *data = //some data
NSString *string = [NSString stringWithFormat:#"%#", data];
How will the data be decoded? Is NSUTF8StringEncoding applied?
Thank you!
This is not the recommended approach. Instead use:
NSString *newString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
This will ensure you have a specified encoding for the data.
In this case, the stringWithFormat: method will send NSData object the description message, get the result, and use that for the content of the newly created string. Essentially, the result is identical to
NSString *string = [data description];
According to NSData's documentation, description returns
An NSString object that contains a hexadecimal representation of the receiver’s contents in NSData property list format.
You probably should be using NSString *string = [[NSString alloc] initWithData: data encoding:SomeFormOfEncoding];
You can view the method details here.
The forms of encoding can be seen here.
I am trying to extract an NSString from the NSKeyedArchiver as follows:
NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *coder = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[coder encodeInt:1 forKey:#"myField"];
[coder finishEncoding];
NSString *myString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"%#", myString);
The problem is that myString is nil (NSLog prints '(null)'). What is wrong with the above code?
Other posts I've read mention that this is usually due to the encoding being wrong (i.e. the NSMutableData is using a different encoding than UTF-8). I've tried all the different types of encoding though, still no luck.
I don't see where you are encoding a string. Normally you would encode an NSString with the NSKeyedArchiver and then unarchive it using an NSKeyedUnarchiver. It doesn't look like you understand how this all works. I recommend reading about archiving using Obj-C.
So far I've discovered in JSON that everything enclosed in { } are objects (objC : NSDictionary) and anything enclosed in [ ] is an array (objC : NSArray).
I've read and re-read this article about the subject>
How to parse JSON into Objective C - SBJSON
I have a .json file with the data modeled like this:
http://elbee101.com/dummySchedule.json
...and now for the code:
SBJSON *parser = [[SBJSON alloc] init];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"http://elbee101.com/dummySchedule.json"]];
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *json_string = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
NSDictionary *schedule = [parser objectWithString:json_string error:nil];
NSDictionary *day = [schedule objectForKey:#"day"];
NSArray *myList = [day objectForKey:#"name"];
NSLog(#"myList %#", myList);
NSArray *numLaps = [myList objectAtIndex:0];
NSLog(#"numlaps%# ", numLaps);
I'm getting "myList (null)" and "numlaps (null)" from the above code?!#
The question: Can somebody please set me straight on the ordering of objects and arrays with respect to my json data? I want to drill down the tree so that I can access the 'day name', 'session starttime/endtime/sessionname', 'numlaps' & 'class' but I can't seem to get past the 'day' object/array(?)
What you're referring to as schedule is the object enclosed in the outermost {}. Try this:
NSDictionary *json = [parser objectWithString:json_string error:nil];
NSDictionary *schedule = [json objectForKey:#"schedule"];
Then continue as before.
Also, if you're on iOS 5 you can use the NSJSONSerialization class -- using it is pretty much the same, you might get better performance, and you don't have to worry about the hassles of using a third-party library.
call this where ever u need to parse
NSMutableArray *arr=[[NSMutableArray alloc] init];
arr=[[Headparse getArrayFromUrl:#"http://elbee101.com/dummySchedule.json"] retain];
NSLog(#"%#",[arr description]);
[arr release];
write this method as custom class use when ever you need
+(NSMutableArray *) getArrayFromUrl: (NSString *)actionType
{
NSMutableData *responseData1= [NSMutableData data] ;
responseData1 = [NSMutableData dataWithContentsOfURL:[NSURL URLWithString:actionType]];
// NSLog(#"%#",responseData1);
NSString *responseString1 = [[NSString alloc] initWithData:responseData1 encoding:NSUTF8StringEncoding];
//NSLog(#"REs:-->%#",responseString1);
//[responseData1 release];
responseData1 = nil;
NSMutableArray *responseArray = [[NSMutableArray alloc]init];
responseArray = (NSMutableArray *)[responseString1 JSONValue];
// NSLog(#"ghfchfvghv%#",responseArray);
[responseString1 release];
return responseArray;
}
This is how i use NSJsonSerialization for parsing the json object.
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:#"http://elbee101.com/dummySchedule.json"]];
NSError *err;
NSDictionary* json = [NSJSONSerialization
JSONObjectWithData:data
options:kNilOptions
error:&err]; //
NSDictionary *schedule_dict = [json objectForKey:#"schedule"];
NSArray *days = [schedule_dict objectForKey:#"day"];//Days Array from day Object
NSDictionary *dayOne = [days objectAtIndex:0];
NSDictionary *dayTwo = [days objectAtIndex:1];
NSLog(#"THE DAY ONE : %#",dayOne);
NSLog(#"THE DAY TWO : %#",dayTwo);
Hope this may help you ....Note : If you don't want to go with NSJsonSerailization(consider reading of this) ,but still the parsing of json data like above will applicable in your case too.