Re: [Zope] <dtml-var x missing> doesn't work?

On Wed, Mar 29, 2000 at 05:42:55PM +0100, Chris Withers wrote:

I'm doing a back link to go on a page (yes, I know browsers have back buttons, but some people don't like to use them ;-) which is easy enough:

<A href="<dtml-var "REQUEST.environ['HTTP_REFERER']">">Back</A>

except that if there is no referer, you get a key error. So I thought I'd try the following:

<A href="<dtml-var "REQUEST.environ['HTTP_REFERER']" missing='/'>">Back</A>

But I still get a key error. I thought the 'missing' attribute was supposed to catch that?

Not quite. You are tripping a key error here so that won't work. Try: <dtml-if "REQUEST.has_key('HTTP_REFERER')"> <dtml-var "REQUEST['HTTP_REFERER']"> </dtml-if> -Petru