Below is a forward of a discussion about the Renderable Base ZClass Product and how it could be integrated into the ZOPE Core. I'd like to see it incorporated into ZClasses - Under the "Basic" tab of the ZClass, having a selectlist labelled "Render Method" from which you'd choose the DTML method to be be displayed when the object is called as <!--#var myObject-->. Can anyone offer suggestions or comments as to a better way to accomplish this? Kevin -----Original Message----- From: Alexander Staubo <alex@mop.no> To: 'Kevin Howe' <ap619@chebucto.ns.ca> Date: October 31, 1999 10:42 PM Subject: RE: ZOPE Advice

I believe __bobo_traverse__() is used exclusively for URL traversal -- it is, strictly speaking, not involved in acquisition or parent/child management, but serves as the means to resolve object paths.

If there is no way to pass REQUEST to __str__(), I believe this is a minor shortcoming and should be remedied in the Zope DTML core. Such as by testing for the presence of an alternative method called __render__(), for example, and using that instead.

Of course, you don't need to use the "with" construct to do what you want. You can easily do something like:

<dtml-var "myobject.render(REQUEST = REQUEST)">

if your object needs to get at this.

-- Alexander Staubo http://www.mop.no/~alex/ "In the end, we all assume room temperature." --John Maynard Keynes

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-----Original Message----- From: Kevin Howe [mailto:ap619@chebucto.ns.ca] Sent: 31. oktober 1999 21:31 To: alex@mop.no Subject: ZOPE Advice

Hi,

There was a simple Product named "Renderable Base ZClass" posted on the ZOPE site not long ago, which allows you to print an object like so:

<dtml-var myobject>

instead of:

<dtml-with myobject> <dtml-var render> </dtml-with>

The "render" method is automatically returned if found.

It works by using the Python __str__ method to override what gets printed. The problem with this method is that you can't pass REQUEST to it, and therefore can't return "render" as a valid DTML method.

I had heard that you could hack the __bobo_traverse__ method to return whatever method you needed, but don't have the ZOPE experience to get it working correctly. I picture it going something of like the code listed below.

class Renderable: def __init__(self): self.steps=[]

def __bobo_traverse__(self, request, name=''): if hasattr (self, 'render'): self.steps.append('render') return self elif hasattr (self, 'index_html'): self.steps.append('index_html') return self else: return '<a href=%s>%s</a>' % (self.__name__, self.title_or_id())