CODEWITHSUNDEEP
iosobjective-cregexnsstringnsattributedstring
cdub
cdub

Reputation: 25701

Using a regex or other mechanism to find tags in a NSAttributedString (or NSString)

I have an NSAttributedString like so:

NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"EThis string shows my #tags. Click on a #tag now."];

What do I use to find the location and end of all tags? Is there a good regex for this or another better way in iOS?

Note: My definition of a tag starts with # and ends with the last alphanumeric character is hit. So a period (.), space, or dash would end the tag.

Thanks.

Upvotes: 0

Views: 606

Answers (3)

CRD
CRD

Reputation: 53000

The class you need is NSRegularExpression and the particular method that will give you the start and length of each match is matchesInString:options:range.

Upvotes: 1

Hussain Shabbir
Hussain Shabbir

Reputation: 15015

If you want to extract the string then you can use NSScanner class like that below:-

NSMutableAttributedString *mtStr = [[NSMutableAttributedString alloc]initWithString:@"EThis string shows my #tags. Click on a #tag now."];
NSString *string = mtStr.string;
// Set up convenience variables for the start and end tag;
NSString *startTag = @"#";
NSString *endTag = @".";
NSString *title;
NSScanner *scanner = [NSScanner scannerWithString:string];
[scanner scanUpToString:startTag intoString:nil];
[scanner scanString:startTag intoString:nil];
[scanner scanUpToString:endTag intoString:&title];
NSLog(@"Value is: %@", title);

Upvotes: 2

Avinash Raj
Avinash Raj

Reputation: 174706

Seems like you want something like this,

#.*?[A-Za-z0-9](?=[.\\s-])

or

#.*?[A-Za-z0-9](?=[. -])

The above regex would match all the strings which starts with # then matches upto the first alphanumeric character which is immediately followed by a space or dot or dash.

DEMO

Upvotes: 2

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