Regular expression to detect valid Youtube links.
Jul 2013
| (http://)?(www.)?(youtube | yimg | youtu).([A-Za-z]{2,4} | [A-Za-z]{2}.[A-Za-z]{2})/(watch\?v=)?[A-Za-z0-9-]{6,12}(&[A-Za-z0-9-]{1,}=[A-Za-z0-9-_]{1,})* |
Jul 2013
| (http://)?(www.)?(youtube | yimg | youtu).([A-Za-z]{2,4} | [A-Za-z]{2}.[A-Za-z]{2})/(watch\?v=)?[A-Za-z0-9-]{6,12}(&[A-Za-z0-9-]{1,}=[A-Za-z0-9-_]{1,})* |