[Zope] Zope Book -> Chap 3 -> Interest Rate Example

[Sylvain Thénault]

On Thursday 05 June à 14:05, Simon Forster wrote:
> 
> On Thursday, June 5, 2003, at 01:51  pm, Sylvain Thénault wrote:
> 
> ><span tal:content="request/form/years">2</span>
> 
> Thank you for that. That fixes one problem but then:
> 
> $<span tal:content="python: here.calculateCompoundingInterest(principal,
> interest_rate,
> periods,
> years)" >1.00</span>
> 
> fails (as I would expect given your posting) but so does
> 
> <span tal:content="python: 
> here.calculateCompoundingInterest(request/form/principal,
> request/form/interest_rate,
> request/form/periods,
> request/form/years)" >1.00</span>
> 
> with error:
> 
> Error Type: NameError
> Error Value: global name 'form' is not defined
> 
> while
> 
> <span tal:content="python: 
> here.calculateCompoundingInterest(request/principal,
> request/interest_rate,
> request/periods,
> request/years)" >1.00</span>
> 
> fails with error
> 
> Error Type: NameError
> Error Value: global name 'principal' is not defined
> 
> Why?

you can not access fields in the same way in the python: 
expression as in others TALES expressions. In a python expression, you
can access form fields by using :

request.form['years']

I suggest you to look at the page template reference [1] before the end
of the book ;-)

[1] http://www.zope.org/Documentation/Books/ZopeBook/current/AppendixC.stx

-- 
Sylvain Thénault                               LOGILAB, Paris (France).

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