[Zope] non-zope objects in zope

[Sam Gendler]

OK, I take my last post back.  I figured out a nice way to do it 
without having to rewrite ANYTHING.  I created a product whose sole 
purpose is to  cause zope to load some modules when it starts up.  
Within the initialize method of that product, it is possible to call 
'allow_module' and 'allow_class', which use some kind of introspection 
to make all members of modules and classes available through the web.  
You can't access modules by name from a dtml-method, but you can access 
class instances.

Example:

In a product called Everest, file called __init__.py:
from AccessControl import ModuleSecurityInfo, allow_class, allow_type, 
allow_module

import cv
import cv.everest
import cv.everest.everest_users

def initialize(context):
     allow_module('cv')
     allow_module('cv.everest')
     allow_module('cv.everest.everest_users')
     allow_class(cv.everest.everest_users.ev_user)
     allow_class(cv.everest.everest_users.user_acct)
     allow_class(cv.everest.everest_users.user_campaign)

Not that allow_module takes a string and allow_class takes an class as 
a parameter.  Seems inconsistent to me.

In a PythonScript called test:
import cv.everest.everest_users
return cv.everest.everest_users.list_users()

which returns a list of ev_user objects defined in the everest_users 
module

In a dtml method:
<dtml-in test prefix="user">
<dtml-var expr="user_item.method1()"> <dtml-var 
expr="user_item.method2()">
</dtml-in>

I assume that method1 and method2 of the ev_user class must return a 
python built-in like dict, list, string, or number, or else must be 
callable or at least be representable as a string.

--sam


On Apr 28, 2004, at 12:10 PM, Sam Gendler wrote:

> I am answering my own question so the next person who bumps into it 
> might have more luck tracking it down.  The following examples are 
> taken from the 'Security' chapter of the Zope Developers Guidde (ZDG). 
>  Note that I still wish there were a way to use external objects 
> unchanged.  Particularly because I have a class heirarchy, where 
> customer objects create campaignh objects, but I want to to return 
> campaign objects that have zope security info, so I have to create 
> instances of my zopified objects from the non-zope objects...very 
> wasteful and slow.
>
> --sam
>
> # an external method that returns Book instances
>
> from AccessControl import ClassSecurityInfo
> from Acquistion import Implicit
> import Globals
>
> class Book(Implicit):
>
>   def __init__(self, title):
>     self._title=title
>
>   # Create a SecurityInfo for this class
>   security = ClassSecurityInfo()
>   security.declareObjectPublic()
>
>   security.declarePublic('getTitle')
>   def getTitle(self):
>     return self._title
>
> Globals.InitializeClass(Book)
>
> # The actual external method
> def GetBooks(self):
>   books=[]
>   books.append(Book('King Lear').__of__(self))
>   books.append(Book('Romeo and Juliet').__of__(self))
>   books.append(Book('The Tempest').__of__(self))
>   return books
>
>
> Or, if you can't modify the original object, try this:
>
> # an external method that returns Book instances
>
> from AccessControl import ClassSecurityInfo
> from Acquisition import Implicit
> import bookstuff
> import Globals
>
> class Book(Implicit, bookstuff.Book):
>   security = ClassSecurityInfo()
>   security.declareObjectPublic()
>   security.declarePublic('getTitle')
>
> Globals.InitializeClass(Book)
>
> # The actual external method
> def GetBooks(self):
>   books=[]
>   books.append(Book('King Lear'))
>   books.append(Book('Romeo and Juliet'))
>   books.append(Book('The Tempest'))
>   return books
>
> On Apr 27, 2004, at 6:26 PM, Sam Gendler wrote:
>
>> I used to be a fairly knowledgable zope user many years ago, but 
>> things have moved on and I've forgotten most of what I know.  I have 
>> a largish library of python modules which define a number of classes 
>> which have methods that perform work in a product.  Currently, much 
>> of the system is managed vai commandline tools which utilize the 
>> library.  We want to ad a web interface, and I figured zope would be 
>> a natural, since everything is already in python.
>>
>> I created external methods which return instances of classes, but if 
>> I try to use those instances from within dtml (iterating over a list 
>> of them, for instance), I just get prompted for authentication 
>> credentials.  I seem to recall that there was some way of applying 
>> zopishness to external object instances at runtime, but I can't 
>> remember what that mechanism is, and I couldn't find it in either the 
>> zope book or the zope bible I went out an bought.
>>
>> For example, if I have a customer class which has name, id, and 
>> revenue members, and I create an external method to return a list of 
>> customer instances, I cannot do the following
>>
>> <dtml-in extListCustomers prefix="cust">
>> <dtml-var expr="cust_item.id"> <dtml-var expr="cust_item.name"> <dtml 
>> var expr="cust_item.revenue">
>> </dtml-in>
>>
>> Thanks
>>
>> --sam
>>
>>
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