[Zope] Beginner DTML question: dereferencing a variable

[Michel Pelletier]

> -----Original Message-----
> From: Martin Dougiamas [mailto:martin@complex.curtin.edu.au]
> Sent: Tuesday, April 06, 1999 7:00 AM
> To: zope@zope.org
> Subject: Re: [Zope] Beginner DTML question: dereferencing a variable
> 
> 
> Martin Dougiamas wrote:
> > I want to check if a folder of that name already exists
> > under the current folder, so I can decide to create it or not.
> >
> > Intuitively, I first tried:
> >
> > <!--#if "theusername"-->
> >   <H3>FOLDER EXISTS</H3>
> > <!--#else-->
> >   <H3>FOLDER DOES NOT EXIST</H3>
> > <!--#/if-->
> 
> I seem to found a solution myself.  This seems to work:
> 
> <!--#if "_.has_key(theusername)"-->
>   <H3>FOLDER <!--#var "theusername"--> EXISTS</H3>
> <!--#else-->
>   <H3>FOLDER <!--#var "theusername"--> DOES NOT EXIST</H3>
> <!--#/if-->
> 
> ...as long as there's not a object with that name UP the
> hierarchy, I suppose.
> 

Yes, acquisition could defeat you with this method.  Try the objectIds
method.  From /lib/python/OFS/ObjectManager.py, 

    def objectIds(self, spec=None):
        """Return a list of subobject ids.

        Returns a list of subobject ids of the current object.  If
'spec' is
        specified, returns objects whose meta_type matches 'spec'.
        """

So you can use the sequence that objectIds returns in your DTML to find
out if any subobjects if meta_type 'Folder' exist with the username your
looking for.

<!--#in "objectIds('Folder')-->
  <!--#if "id == theusername"-->
    Folder Exists
  <!--#/if-->
<!--#/in-->

You want to use a DTML Method to get the expected result.

-Michel


> If there's a cleaner way to do this I'd still like to know it.
> 
> Cheers!
> Martin
> 
> 
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