Not following RegEx recursion in PCRE

[ret]

I have an application I have been working on that uses regular expressions to extract email addresses from my customer's website.

on mouseUp
put text of field "myHTML" into myHTMLvar

put matchText(myHTMLvar,"([\w]+@[\w]{2,}+\.[\w]{2,}(?R)?)",myEMAIL) into myresult

answer myresult
answer myEMAIL

end mouseUp

I get the first email address just fine, but I am not understanding how to get the PCRE to do recursion. PCRE does not accept the /g modifier and after several days of searching for an alternative (like a combination of (?m) and ^ and $, I am at a loss for how to solve this problem via PCRE regex. I know it is possible, but I am just not getting it.

All the PHP examples online use a function called preg_match_all, but that does not appear to be valid in LiveCode.

I assume I may have to use a chunk variant to find where the first match hits and then start the next match from that point, thus writing a recursive function myself, but I am hoping that is not the case.

Any insight is appreciated.

Rick

[Thierry]

I assume I may have to use a chunk variant to find where the first match hits and then start the next match from that point, thus writing a recursive function myself

Hello Ret,

Yes, you are right; that's the way to go.


Otherwise, I have a not free library with more powerful API
to deal with these kind of problems.

Kind regards,

Thierry

[ret]

Thierry - thank you so much for the advice and link to code example. This worked great. I very much appreciate your help!

Here is how I modified your code for solving my problem. I am using this with the revBrowserGet functions to populate a "myHTML" field on my main LiveCode card from the company's website, but this code would work for any website containing email data. I am glad to share the revBrowserGet code I am using with anyone who wants to see it. This works in 7.x and 8.x versions of LiveCode.

on mouseUp
local RX
local x
local myEMAIL
local my2ndEmail

put "([\w]+@[\w]{2,}+\.[\w]{2,}(?R)?)" into RX

put text of field "myHTML" into myHTMLvar

repeat while matchChunk(myHTMLvar, RX, p1start,p1End)
put matchText(myHTMLvar,RX,myEMAIL) into myresult
put myEMAIL &cr after my2ndEMAIL

#commenting next two lines out, but useful during testing
#answer myresult
#answer my2ndEMAIL

delete char 1 to p1End of myHTMLvar
end repeat

answer my2ndEMAIL

end mouseUp

Thanks again for saving me a lot of time. I was really losing sleep on this one over the past few days.

Rick

[Thierry]

Thanks again for saving me a lot of time. I was really losing sleep on this one over the past few days.

Hi Rick, I'm happy that you made it.

And yes, this forum is great for sharing experiences

In case you need to replace any patterns in a text, remember that
the replaceText() LC function has on its own
the same behavior as the '/g' from Perl or other languages...
Hence, no needs for a repeat while ...

Regards,

Thierry