Trimming NSString with multiple conditions - iphone

Question

I'm having a hard time with trimming some characters from a NSString. Given an existing text view with text in it, the requirements are:
Trim leading spaces and newlines (Basically ignore any leading whitespace and newlines)
Copy up to max of 48 chars into the new string OR until a newline is encountered.
I have found that I could do the first requirement from another SO question here with the code:
NSRange range = [textView.text rangeOfString:#"^\\s*" options:NSRegularExpressionSearch];
NSString *result = [textView.text stringByReplacingCharactersInRange:range withString:#""];
However, I'm having trouble with doing the 2nd requirement. Thank you!

Answer 1

This will do what your looking to do. Also it is an easier way to trim leading whitespace and newlines.
NSString *text = textView.text;
//remove any leading or trailing whitespace or line breaks
text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
//find the the range of the first occuring line break, if any.
NSRange range = [text rangeOfString:#"\n"];
//if there is a line break, get a substring up to that line break
if(range.location != NSNotFound)
text = [text substringToIndex:range.location];
//else if the string is larger than 48 characters, trim it
else if(text.length > 48)
text = [text substringToIndex:48];

Answer 2

This should work. Basically what it does is it loops through the characters in the text of the textview and checks if the character it's currently on is a newline character. It also checks if it has reached 48 characters yet. If the character is not a new line character and it has not reached 48 characters yet, then it adds the character to a result string:
NSString *resultString = [NSString string];
NSString *inputString = textView.text;
for(int currentCharacterIndex = 0; currentCharacterIndex < inputString.length; currentCharacterIndex++) {
unichar currentCharacter = [inputString characterAtIndex:currentCharacterIndex];
BOOL isLessThan48 = resultString.length < 48;
BOOL isNewLine = (currentCharacter == '\n');
//If the character isn't a new line and the the result string is less then 48 chars
if(!isNewLine && isLessThan48) {
//Adds the current character to the result string
resultString = [resultString stringByAppendingFormat:[NSString stringWithFormat:#"%C", currentCharacter]];
}
//If we've hit a new line or the string is 48 chars long, break out of the loop
else {
break;
}
}