You could look for hash tags without an "&" in front of it. something like this: (?:[^&]|^)##([a-z0-9_\-]+) ~Mahcsig
On Mon, Aug 10, 2009 at 10:24 AM, Paul Vernon < [email protected]> wrote: > > Ok, so I thought I'd cracked this and I have to some extent but not > completely. > > The well known hashtag RegEx I see in most Twitter examples is a variant of > this ##([a-z0-9\-_]+) > > The problem with this is that if you run it over a string that contains > HTML entities, it will recognise those HTML entities as hashtags too... > > E.g. #mytrendingtopic is a valid hashtag but this isn't. > > #mytrendingtopic *and* #39 are recognised as hashtags... > > Now, my latest crack at this is a bit more complex and looks like this: > > ##(([a-z_\-]+[0-9_\-]*[a-z0-9_\-]+)|([0-9_\-]+[a-z_\-]+[a-z0-9_\-]+)) > > Which picks out: > > 1. All hashtags starting with alpha and containing 0 or more numbers with _ > an - at any position > 2. All hashtags starting with numbers and containing 1 or more alpha with _ > an - at any position > > This RegEx works well but it's still not quite right. The problem with this > though in that if the film 2001 or 2010 we're hashtags e.g. #2001 or #2010 > then they would get missed by the RegEx. All other hashtags are recognised > just fine and HTML entities are ignored so for the most part it's better > than the original RegEx as widely used. > > I've been working on a fix for this problem and been looking at using > lookahead and lookbehind but it seems CF doesn't support all the features I > need, i.e. no negative lookbehind. > > So if anyone can improve on my current RegEx so I can pick out > #mytrendingtopic but not #39 from the above example, I'd appreciate it very, > very much... > > Paul > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:325325 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
