URI.SafeIframeRegexp
TYPE: string/null
VERSION: 4.4.0
DEFAULT: NULL
--DESCRIPTION--

    A PCRE regular expression that will be matched against an iframe URI.  This is
    a relatively inflexible scheme, but works well enough for the most common
    use-case of iframes: embedded video.  This directive only has an effect if
    %HTML.SafeIframe is enabled.  Here are some example values:

- %^http://www.youtube.com/embed/% - Allow YouTube videos
    
- %^http://player.vimeo.com/video/% - Allow Vimeo videos
    
- %^http://(www.youtube.com/embed/|player.vimeo.com/video/)% - Allow both

    Note that this directive does not give you enough granularity to, say, disable
    all autoplay videos.  Pipe up on the HTML Purifier forums if this
    is a capability you want.

--# vim: et sw=4 sts=4
