[Zope] Avoiding acquisition aka testing for contained objects

If I want to know whether a certain object is contained in the current folder I do this: <dtml-if "'index_html' in this().objectIds()"> yes it's here <dtml-else> not here </dtml-if> Id like to know whether this is the best/most efficient way to do it. Things like hasattr() are subject to aquisition i.e. they would find an index_html method along the acquisition path; something I do not want. I also cannot bracket everything in a <dtml-with ... only> because chopping my namespace is not what I want either. TIA, Stefan -- Things work better when plugged in