JSON Processing in iOS: Removing newlines - ios

Question

I am trying to decode json being sent to my application from Twitter's Streaming API.
Twitter will send my client data which has the following structure:
The body of a streaming API response consists of a series of newline-delimited messages, where "newline" is considered to be \r\n (in hex, 0x0D 0x0A) and "message" is a JSON encoded data structure or a blank line.
They basically separate tweets with \r\n. Sometimes they send you one tweet, sometimes they send you many at once.
Decoding the 'many' case is problematic for me. I use NSJSONSerialization class built into iOS. The problem is that it reads the first tweet and then see's the \r\n and considers this as garbage and returns an empty array and accompanying error.
To get around this problem, I use the following code to basically remove the newlines.
// json is the received json data
NSString* responseString = [[NSString alloc] initWithData:json encoding:NSASCIIStringEncoding];
NSMutableArray* responseMutableArray = [[responseString componentsSeparatedByString:#"\r\n"] mutableCopy];
[responseMutableArray removeLastObject];
NSArray* responseArray = [NSArray arrayWithArray:responseMutableArray];
[responseMutableArray removeAllObjects];
NSError* error;
for(NSString* tweetString in responseArray)
{
NSDictionary* dict = [NSJSONSerialization JSONObjectWithData:[tweetString dataUsingEncoding:NSUTF8StringEncoding] options: NSJSONReadingAllowFragments|NSJSONReadingMutableContainers error:&error];
[responseMutableArray addObject:dict];
}
//responseMutableArray contains the parsed tweets
The approach is, convert the data into a NSString, NSString into an array (by spliting by \r\n), array back into data and then parse the JSON into a dictionary. Its a messy process and I wonder if there is something more efficient way that I can do this.
Thanks very much
Vb

Answer 1

Disclaimer: I actually got here by encountering this issue myself.
I think the simplest solution would be a revision of #Elmundo 's answer that removes the newlines completely. It worked for me.
Note: this is Swift version 3.something
guard var string = String(data: data, encoding: .utf8) else {
return
}
string = string.stringByReplacingOccurrencesOfString("\r\n", withString: "")
guard let data = string.data(using: .utf8) else {
return false
}
do {
let json = try NSJSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.allowFragments) as! [String:Any]
}catch let e as NSError {
print(e.description)
}

Answer 2

Try this:
NSString *string = [[NSString alloc] initWithData:json encoding:NSASCIIStringEncoding]:
string = [NSString stringWithFormat:#"[%#]", [string stringByReplacingOccurrencesOfString:#"\\r\\n" withString:#","]];
NSArray *array= [NSJSONSerialization JSONObjectWithData:[string dataUsingEncoding:NSUTF8StringEncoding] options:NSJSONReadingAllowFragments|NSJSONReadingMutableContainers error:&error];

Answer 3

Touch this:
let stringData = String(data: data, encoding: NSUTF8StringEncoding)
if let strData = stringData {
let newString = strData.stringByReplacingOccurrencesOfString("\r\n", withString: "\\r\\n")
if let newString = newString {
do {
let dict:[AnyObject] = try NSJSONSerialization.JSONObjectWithData(newString.dataUsingEncoding(NSUTF8StringEncoding)!, options: [.AllowFragments, .MutableContainers]) as! [AnyObject]
}catch let e as NSError {
print(e.description)
}
}
}