[Zope] Understanding dtml and/or its variables

[Dieter Maurer]

Damir Bartakovic writes:
 > I am using ZnolkSQLWizard and it creates output like
 > <INPUT TYPE="TEXT" NAME="table.name"> ...
 > 
 > Now I am trying to force the user not to leave the field blank.
 > Usually it works with <dtml-unless "somevariable"> ...  once again!
 > ....</dtml-unless>
 > 
 > but with <dtml-unless "table.name">  ... I get the error:
 > Error Type: NameError
 > Error Value: table (The Traceback is at the end)
 > 
 > Like it seems it don't like the '.'?
It likes '.' but interprets it differently:

  Inside "...", you are in the realm of Python expressions.
  In Python, the "." is not part of a name (as in DTML)
  but it is an operator: the left operand is an object,
  the right one a name and the result is the object's attribute
  of the given name.

  You can use, e.g. "_['table.name']" to access the object
  with name "table.name" from Python.

The official Zope book and

    URL:http://www.dieter.handshake.de/pyprojects/zope/book/chap3.html

will tell you more about these issues.


Dieter