WTForm i array - UnboundField FormField

Question

I am a beginner in using WTForms and Python. I have got a problem with the aggregation of WTForm in a dict or list, rendering through jinja2. For example :

class CJanuary(Form):
    nr          = int(12)
    netto       = DecimalField(u'Salary netto',         default = 0, places = 2)
    brutto      = DecimalField(u'Salary brutto',        default = 0, places = 2)    

class InputMonthlyForm(Form):
    january = FormField(CJanuary)
    months  = [FormField(CJanuary)]

If I render it as below:

{{form.january.netto}}

In this case everything is ok, I get source:

<input id="january-netto" name="january-netto" type="text" value="0.00">

But if I try render from list:

{{form.months[0].netto}}

in source I get nothing.

Checking what is in the list:

{{form.months[0]}}

I get:

<UnboundField(FormField, (<class 'apps.placowy.forms.InputMonthlyForm.CJanuary'>,), {})>

I have searched the internet but I can not find any solution. Is it maybe not possible to aggregate WTForm in an array?

Answer 1

Try to use FieldList instead of list:

class CJanuary(Form):
    nr          = int(12)
    netto       = DecimalField(u'Salary netto',         default = 0, places = 2)
    brutto      = DecimalField(u'Salary brutto',        default = 0, places = 2)    

class InputMonthlyForm(Form):
    january = FormField(CJanuary)
    months  = FieldList(FormField(CJanuary))