iOS Regular expressions / pulling string from inside a string

dusker · Jul 21, 2009

Hi Guys!
I'm working on an app of mine, but i came across a problem i find pretty hard to bite. Inside a NSString i'll have a pretty long html code, and i'd like to pull out of that string, substrings that are contained inside certain tags. So for example i'd like to get what's inside and tags.
There'll be couple of lines containing these tags so i'll need this solution to run inside a loop.

Any help will be greatly appreciated.

greetings
peter

jnic · Jul 21, 2009

Try NSXMLParser.

dusker · Jul 21, 2009

@jnic thanks for the clue! Would you (or someone else) care to post a short snippet of what methods to use? Say we got the following:

Code:

NSString *str = @"<html><body><font><b>hello</b></font> <font><b>world</b></font></body></html>";
NSXMLParser *parser = [[NSXMLParser alloc] initWithData:str];

how to get the parser to return what's enclosed inside and 

thanks in advance

ChOas · Jul 21, 2009

dusker said:
@jnic thanks for the clue! Would you (or someone else) care to post a short snippet of what methods to use? Say we got the following:

Code:

NSString *str = @"<html><body>hello world</body></html>"; NSXMLParser *parser = [[NSXMLParser alloc] initWithData:str];

how to get the parser to return what's enclosed inside and 

thanks in advance

Check this example:

https://developer.apple.com/iphone/...ts.html#//apple_ref/doc/uid/20002265-BCIJFGJI

in short you would probably want to set up 2 BOOLs like inFont and inB so you know when you are within , capture all data until the tags are closed and then clear the BOOLs again

Luke Redpath · Jul 21, 2009

Depending on your needs, NSXMLParser may be overkill; you might be able to accomplish what you want using regular expressions - try the RegexKitLite framework.

firewood · Jul 21, 2009

use Javascript

Javascript supports regex, and there are several xml/html parsing libraries available for Javascript. You can run the JS code inside a hidden UIWebview. Calling a JS parser from Obj-C might be a lot easier than rolling the equivalent parser in Obj-C.

dejo · Jul 21, 2009

Well, I'm gonna suggest looking into NSScanner if the structure of what you're pulling from is not overly complex.

dusker · Jul 22, 2009

Javascript supports regex, and there are several xml/html parsing libraries available for Javascript. You can run the JS code inside a hidden UIWebview. Calling a JS parser from Obj-C might be a lot easier than rolling the equivalent parser in Obj-C.

thanks for a tip, could you recommend any paticular js html parser?

Well, I'm gonna suggest looking into NSScanner if the structure of what you're pulling from is not overly complex.

I think the html i need to parse is too complex for nsscanner

Would anyone care to post some snippet of regex expression that would pull data from inside tag?

ChOas · Jul 22, 2009

dusker said:
thanks for a tip, could you recommend any paticular js html parser?

I think the html i need to parse is too complex for nsscanner

Would anyone care to post some snippet of regex expression that would pull data from inside tag?

/(.*?)<\/b><\/font>/ism

Search

Search

iOS Regular expressions / pulling string from inside a string

dusker

macrumors member

jnic

macrumors 6502a

dusker

macrumors member

ChOas

macrumors regular

Luke Redpath

macrumors 6502a

firewood

macrumors G3

dejo

Moderator emeritus

dusker

macrumors member

ChOas

macrumors regular

Our Staff