It seems that even after adding the Config params to enable YouTube and Vimeo Iframes I still get an exception error. "Element 'iframe' is not supported[..]"
return array(
'encoding' => 'UTF-8',
'finalize' => true,
'preload' => false,
'settings' => array(
'default' => array(
'HTML.Doctype' => 'XHTML 1.0 Strict',
'HTML.Allowed' => 'blockquote,div,b,strong,i,em,a[href|title],ul,ol,li,p[style],br,span[style],img[width|height|alt|src]',
'CSS.AllowedProperties' => 'font,font-size,font-weight,font-style,font-family,text-decoration,padding-left,color,background-color,text-align',
"HTML.SafeIframe" => 'true',
"URI.SafeIframeRegexp" => "%^(http://|https://|//)(www.youtube.com/embed/|player.vimeo.com/video/|api.soundcloud.com/tracks/)%",
'AutoFormat.AutoParagraph' => true,
'AutoFormat.RemoveEmpty' => true,
),
),
Your issue is that you are using Doctype XHTML 1.0 Strict.
In the documentation of HTML.SafeIframe it is stated that:
Whether or not to permit iframe tags in untrusted documents. This directive must be accompanied by a whitelist of permitted iframes, such as %URI.SafeIframeRegexp, otherwise it will fatally error. This directive has no effect on strict doctypes, as iframes are not valid.
So you should use Transitional instead. The following configuration will work correctly:
return array(
'encoding' => 'UTF-8',
'finalize' => true,
'preload' => false,
'settings' => array(
'default' => array(
'HTML.Doctype' => 'XHTML 1.0 Transitional',
'HTML.Allowed' => 'iframe[src|width|height|class|frameborder],blockquote,div,b,strong,i,em,a[href|title],ul,ol,li,p[style],br,span[style],img[width|height|alt|src]',
'CSS.AllowedProperties' => 'font,font-size,font-weight,font-style,font-family,text-decoration,padding-left,color,background-color,text-align',
"HTML.SafeIframe" => true,
"URI.SafeIframeRegexp" => "%^(http://|https://|//)(www.youtube.com/embed/|player.vimeo.com/video/|api.soundcloud.com/tracks/)%",
'AutoFormat.AutoParagraph' => true,
'AutoFormat.RemoveEmpty' => true,
),
),
);