Get first sentence of textview - iphone

Question

I am trying to get the first sentence of a text view. I have the following code but am getting an out of bounds error. Thank You. Or are there any ways that aren't really complex.
-(IBAction)next:(id)sender
{
NSRange ran = [[tv.text substringFromIndex:lastLocation] rangeOfString:#". "];
if(ran.location != NSNotFound)
{
NSString * getRidOfFirstHalfString = [[tv.text substringFromIndex:lastLocation] substringToIndex:ran.location];
NSLog(#"%#",getRidOfFirstHalfString);
lastLocation+=getRidOfFirstHalfString.length;
}

Answer 1

How about:
NSString *finalString = [[tv.text componentsSeparatedByString:#"."] objectAtIndex:0] // Get the 1st part (left part) of the separated string
Go through the textview's text and divide the text into separate components where you find a period by calling componentsSeperatedByString on tv.text. You want the first sentence, which would be the 0th object in the array.

Answer 2

I know you've already accepted an answer to this question, but you might want to consider using the text view's tokenizer instead of just searching for the string ". " The tokenizer will automatically handle punctuation like !, ?, and closing quotes. You can use it like this:
id<UITextInputTokenizer> tokenizer = textView.tokenizer;
UITextRange *range = [tokenizer rangeEnclosingPosition:textView.beginningOfDocument
withGranularity:UITextGranularitySentence
inDirection:UITextStorageDirectionForward];
NSString *firstSentence = [textView textInRange:range];
If you want to enumerate all of the sentences, you can do it like this:
id<UITextInputTokenizer> tokenizer = textView.tokenizer;
UITextPosition *start = textView.beginningOfDocument;
while (![start isEqual:textView.endOfDocument]) {
UITextPosition *end = [tokenizer positionFromPosition:start toBoundary:UITextGranularitySentence inDirection:UITextStorageDirectionForward];
NSString *sentence = [textView textInRange:[textView textRangeFromPosition:start toPosition:end]];
NSLog(#"sentence=%#", sentence);
start = end;
}

Answer 3

Try checking that the substring was actually found.
NSRange ran = [tv.text rangeOfString:#". "];
if(ran.location != NSNotFound)
{
NSString * selectedString = [tv.text substringToIndex:ran.location];
NSLog(#"%#",selectedString);
}

Answer 4

You could alternatively try using NSScanner like this:
NSString *firstSentence = [[NSString alloc] init];
NSScanner *scanner = [NSScanner scannerWithString:tv.text];
NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:#"."];
[scanner scanUpToCharactersFromSet:set intoString:&firstSentence];
I'm not sure if you want this, but since you want the first sentence, you could append a period (you probably know how to do this, but it doesn't hurt to show it anyway):
firstSentence = [firstSentence stringByAppendingFormat:#"."];
Hope this helps!
PS: If it didn't work for you, maybe the text view doesn't actually contain any text.