[Zope] What's up with calling DTML methods with arguments?

[John Morton]

Scenario: 

I have a GUF based authentication system that uses a SQL database to
store user profiles. The primary key of the user table is a serial
number, so my users can change there username anytime without throwing the 
tables into a mess, but usernames are otherwise used as a unique ID
for a user, so I need to do a name to user_id lookup before doing most 
queries. 

I've also got it set up to handle different password hash methods so I 
can migrate to a new one if the present one sucks - to make this easy
I've got a DTML method called encodePassword that takes a password and 
the (typically acquired) pwd_format property and gets the appropriate
external method to turn it into the password hash. 

So in my password change report I want to do something like this:

(name and new_password arrive from the request, pwd_format is an
acquired default)

<dtml-call "sql_change_password(
 user_id=sql_get_user_id(name=name),
 password=encodePassword(password=new_password),
 pwd_format=pwd_format
)">
 

But I can't because Zope throws a fit about infinite
recursion. Bummer. Ok, how about this:

<dtml-let password="encodePassword(password=new_password)" 
             user_id="sql_get_user_id(name=name)">
 <dtml-call "sql_change_password(
    user_id=user_id,
    password=password,
    pwd_format=pwd_format)">
</dtml-let>

That doesn't work either. It seems that when I pass arguments to the
method encodePassword, it ceases to acquire anything else from the
environment, including my default pwd_format value, and all the
external methods that live in the same folder. 

This is a pain. No arguments, it acquires, give it arguments, it
doesn't. If I wanted it to not acquire things from the environment I'd
use the <dtml-with ... only> container, but someone has made that call 
it seems. So how do I supply a method with an argument and tell it to
look in it's folder for other properties and methods to acquire? Am I
forever doomed to wrap annoying <dtml-let> containers around
all of the methods that I want to acquire properties from the rest of
Zope?

John.