Detect URL in NSString - ios

Question

I'm currently using a UITextView in a UITableViewCell in order to make links clickable, but this is giving very poor performance.
So I was wondering if it's possible to detect links in a NSString and if there is a link, use the UITextView, otherwise just use a UILabel.

Answer 1

Absolutely. Use NSDataDetector (NSDataDetector Class Reference)

Answer 2

I guess you are familiar with regexes to detect URLs, so in order to get one or the other type of view in your cell, you can simply return two different UITableViewCells from your tableView:cellForRowAtIndexPath: method.
It could look like this (please notice, typed in the browser not tested):
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *dataString = // Get your string from the data model
// Simple pattern found here: http://regexlib.com/Search.aspx?k=URL
NSString *URLpattern = #"^http\\://[a-zA-Z0-9\-\.]+\\.[a-zA-Z]{2,3}(/\\S*)?$";
NSError *error = NULL;
NSRegularExpression *URLregex = [NSRegularExpression regularExpressionWithPattern:URLpattern
options:NSRegularExpressionCaseInsensitive
error: &error];
NSUInteger numberOfMatches = [URLregex numberOfMatchesInString:string
options:0
range:NSMakeRange(0, [string length])];
if ( numberOfMatches == 0 ) {
static NSString *PlainCellIdentifier = #"PlainCellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier] autorelease];
}
cell.textLabel.text = timeZoneWrapper.localeName;
}
else {
static NSString *FancyCellIdentifier = #"FancyCellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier] autorelease];
}
// Configure cell view with text view here
}
return cell;
}

Answer 3

Using this snip of code you would be able to find and get http url in UILable using NSDataDetector:
NSDataDetector* detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSArray* matches = [detector matchesInString:yourString options:0 range:NSMakeRange(0, [yourString. length])];
NSLog(#"%#",matches) ;
NSMutableAttributedString *MylabelAttributes =
[[NSMutableAttributedString alloc] initWithString:yourString];
for (int index = 0 ; index < matches.count; index ++) {
NSTextCheckingResult *textResult = [matches objectAtIndex : index];
NSTextCheckingType textResultType = textResult.resultType;
NSRange testRange = textResult.range;
NSURL *testUrl = textResult.URL ;}
After applying this code, you will be able to attribute your `UILabel` text:
[MylabelAttributes addAttribute:NSLinkAttributeName value:testUrl range: testRange];
[MylabelAttributes addAttribute:NSFontAttributeName
value:[UIFont boldSystemFontOfSize:7.0]range:NSMakeRange(0,yourString.length)];