Struggling with regular expressions

Discussion in 'iOS Programming' started by isthisonetaken, May 20, 2012.

  1. isthisonetaken macrumors regular

    Joined:
    Jun 29, 2006
    #1
    Hey All,

    I have an app that gets some returned data from a website and stores it in an NSString. The returned data is HTML with some information I want to get that's dynamic (it's always different when the data is returned). The stuff I'm looking for is buried within the HTML in lines like this:

    <td align="center" colspan="1"> <a class="ada" title="11:00 P.M.">11:00 P.M.</td><td align="left" colspan="1"> TO Some Destination</td>

    I tried using an XML scanner, but it kept failing out with errors not liking the way the returned code was formatted I guess. After doing some Googling, it seems I should be using regular expressions to do a search through the string to find the data. I have this so far:

    Code:
    // create a regex to find the times in the returned string
        NSRegularExpression *timeRegex = [[NSRegularExpression alloc] initWithPattern:@""
                                                                              options:NSRegularExpressionCaseInsensitive error:nil];
        // find an array of the times
        NSArray *times = [timeRegex matchesInString:self.returnedDataString options:0 range:NSMakeRange(0, [self.returnedDataString length])];
    My problem is the regex expression which right now is @"", which obviously isn't what I want. I read about regular expressions, but still don't really know how to start? I should mention as well that there are normally multiple times and occasionally no times returned.

    Any thoughts or help?
     
  2. ArtOfWarfare macrumors G3

    ArtOfWarfare

    Joined:
    Nov 26, 2007
    #2
    I'm not quite sure how to do what you want, but an idea I have would be, if times are always given in A.M. Or P.M. (as opposed to 24 hour time, my preferred format,) then you could search for the string ".M." - it seems quite improbable that that series of characters would appear outside of a string giving the time. Then just look at the characters before that.
     
  3. robvas macrumors 68030

    Joined:
    Mar 29, 2009
    Location:
    USA

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