[Zope] Getting the requested object's properties (CMF/LoginManager)

[Sreeram Ramachandran]

On Sat, May 19, 2001 at 12:50:50PM -0400, Tres Seaver wrote:
> Sreeram Ramachandran <gro.mareers@sreeram.org> wrote:
> 
> > Instead of an HTTP-AUTH dialog (as it now stands), I would like to put out
> > a LoginManager-style "forbiddenPage". The following will not work, because
> > the "something follows here" (plus the standard_html_footer) section will
> > still get output:
> > 
> > standard_html_header:
> >   if ...: // same check as above
> >     <dtml-var forbiddenPage>
> >   else:
> >     ...   // normal stuff
> > 
> > some_page:
> >   <dtml-var standard_html_header>
> >   ... something follows here ...
> >   <dtml-var standard_html_footer>
> 
> How about::
> 
>   <dtml-return forbiddenPage>
> 
> Tres.
> -- 
> ===============================================================
> Tres Seaver                                tseaver@digicool.com
> Digital Creations     "Zope Dealers"       http://www.zope.org

That won't work, because, although standard_html_header will return, some_page
will continue and output the extra stuff ("something follows here" + footer).

But, I found a way out! I now use "<dtml-raise>". In fact, using the same
strategy, I am able to fix other minor irritations, such as:
  - pesky browsers (such as IE) showing their "friendly" error pages instead
    of your nicely-crafted HTML (for stuff like "LoginRequired"/"Forbidden")
  - the W3C HTML validator <http://validator.w3.org/> refusing to process any
    page unless the return code is 200.
  - trying to arbitrarily stop further DTML processing (and not just within
    the current document/method).

I think the solution is pretty neat. It fixes all the above, is neat (i.e.,
without touching the Zope Python code at all) and is concentrated in a couple
of places (such as standard_error_message, loginForm and standard_html_header)
so that the rest of your site won't have to worry about it.

I'll be happy to explain the details if anyone is interested or faces similar
problems.

Cheers!
Sreeram.

-- 
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Observation is the essence of art.
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