From: Stefano Crocco <stefano.crocco@...>
Date: 2008-04-08T05:31:19+09:00
Subject: Re: Extract youtube video id with eval?

On Monday 07 April 2008, comopasta Gr wrote:
> Hi,
>
> I'm just doing the research but maybe someone already knows...
>
> I have a youtube video url:
> http://www.youtube.com/watch?v=n1NVfDlU6yQ&feature=related
> (&feature might or might not be present)
>
> I can get the thum of the video using:
> http://img.youtube.com/vi/n1NVfDlU6yQ/default.jpg
>
> So, I just need to use the video id.
>
> Now, how to extract the video id easily? Eval?
> Yeah simple I know...I'm working on it in the meanwhile.
>
> Thanks

If you only need to extract the part of the url between watch?v= and either 
the end of the string or the &feature part, you can use a simple regexp:

id = url.match(/watch\?v=(.*?)(?:&feature|\Z)/)[1]

This matches the string 'watch?v= followed by any number of characters and by 
either the string &feature or the end of the string. The middle part (which I 
described as "any number of character") are then stored in the first subgroup 
(the element with index 1 of the MatchData object returned by match).

You can create the image url with:

img_url = "http://img.youtube.com/vi/#{id}/default.jpg"

I hope this helps

Stefano