[Zope] Re: meta_type in DTML returns incorrect type

[Dario Alcocer]

Dieter Maurer wrote:
> Dario Alcocer wrote at 2004-1-1 13:47 -0800:
> 
>>I'm working with the AddressBook example from the book, "Zope Bible". 
>>The example uses the following to conditionally display an edit link for 
>> an AddressBook entry in the object's index_html (rendered via a 
>>DTMLFile() object):
>>
>><dtml-if "meta_type=='AddressBook Entry'"> | <a 
>>href="./editEntryForm">Edit Entry</a></dtml-if>
>>
>>However, this never renders an "Edit Entry" link because meta_type's 
>>value is 'AddressBook' (i.e. the type of the containing object) and not 
>>the expected value 'AddressBook Entry'.  I've verified this by printing 
>>out the type of self.meta_type.
> 
> 
> This means:
>  
>   either your "index_html" is "applied" to the "AddressBook"
>      (and not an entry)

I'm not sure what you mean, but the object *should* be an Entry object. 
  The AddressBook class supports an addEntry method; the entries are 
store in a dictionary kept by AddressBook:

     class AddressBook(SimpleItem):
         "An AddressBook object"
         meta_type = "AddressBook"
         def addEntry(self, FirstName = "", MiddleInitial = "",
                      LastName = "", REQUEST = ""):
             "Method to add entry to an AddressBook"
             id = self.LastEntryID = self.LastEntryID + 1
             id = str(id)
             entry = Entry(id, FirstName, MiddleInitial, LastName)
             self.Entries[id] = entry
             self.__changed__(1)

     class Entry(Item, Persistent, Implicit):
         "Address Book Entry"
         meta_type = "AddressBook Entry"
         def __init__(self, id, FirstName, MiddleInitial,
                      LastName):
             self.id = id
             self.editEntry(FirstName, MiddleInitial, LastName)
         index_html = DTMLFile('dtml/entryDetails', globals())

Does it matter that Entry inherits from Item and not from SimpleItem? 
Maybe the fact that Implicit is a base class means that meta_type is 
acquired from AddressBook.

>   or an "AddressBook Entry" does not have a "meta_type" attribute.

Nope, as you can see from above, the Entry class does in fact have a 
meta_type member.

Any other hints you might have will be greatly appreciated.