[Zope] - Is this a bug?

Mon, 14 Dec 1998 12:26:11 +0000

Butch Landingin wrote:
> 
> I've just started playing around with Zope and the Plutonia example so
> I don't know enough to figure this one out:
> 
> I defined the standard_html_header as follows :
> 
> ---start of standard_html_header--------
> 
> <HTML><HEAD>
>    <TITLE><!--#var document_title--></TITLE>

This will display the document_title of
standard_html_header, which is probably
blank. :)

>    </HEAD>
>    <BODY BGCOLOR="#FFFFFF">
>    <P><!--#var PlutoniaLogo--></P>
> 
> ---end of standard_html_header--------
> 
> and in each of the the folders News, Products and Research,
> there an index_html (e.g. title : Plutonia News) with the following
> text (or something like it) :
> 
> -----start of index_html---------
> 
> <!--#var standard_html_header-->
> <H2> <!--#var document_title--></H2>
> <P> Welcome to Plutonia News Section!</P>
> <P> We don't have any news items to report yet though. </P>
> <!--#var standard_html_footer-->
> 
> -----end of index_html---------
> 
> When the page is rendered, the document_title is displayed correctly
> as <H2> Plutonia News </H2>.
> However the standard_html_header template expansion has this quirky
> behavior :
> the PlutoniaLogo is translated correctly into PlutoniaLogo but the
> document_title in between the <TITLE> tags is empty!
> 
> See the rendered HTML:
> 
> ---start of rendered HTML --------
> 
> <HTML><HEAD>
>    <TITLE></TITLE>
>    </HEAD>
>    <BODY BGCOLOR="#FFFFFF">
>    <P><IMG SRC="PlutoniaLogo" ALT="PlutoniaLogo"></P>
> <H2> Plutonia News</H2>
> <P> Welcome to Plutonia News Section!</P>
> <P> We don't have any news items to report yet though.</P>
> </BODY></HTML>
> 
> ---end of rendered HTML --------
> 
> Question: What's the difference in evaluating the document_title
> inside standard_html_header and evaluating it inside index_html ? 

No difference.  It always displays the title of the document
being rendered.

> Is
> there no dynamic or recursive expansion of variables at all?

Yes.

> Is there anything that I'm missing here?

Yes, it subtle and most people miss it, which is 
why we're going to change the software. :)

> If there is no recursive expansion of
> variables, is there anyway I can put a dynamically evaluated variable
> in the standard_html_header so that it displays the correct title?

The problem is that documents are *really* methods, but people
often want to use them as data.  Then again, sometimes you want them 
to act like methods.

In this example, you want index_html to act like data, with it's own
properties (e.g. title). OTOH, you want standard_html_header to act like
a method and displat the title of index_html, not it's own title
(or the title of the folder).

I plan to fix this by:

  - Renaming the current document objects to "DTML Methods".

  - Create a new object type: "DTML Documents".  These objects
    will let you define more or less arbitrary properties and
    will display their own properties rather than folder properties 
    first.

> Other than this, I think Zope is pretty cool.

Cool!

Jim

--
Jim Fulton           mailto:jim@digicool.com
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