WTForms erstellen variable Anzahl von Feldern

Question

Wie würde ich dynamisch einige Formularfelder mit verschiedenen Fragen erstellen, aber die gleichen Antworten?

from wtforms import Form, RadioField 
from wtforms.validators import Required 

class VariableForm(Form): 

    def __init__(formdata=None, obj=None, prefix='', **kwargs): 
     super(VariableForm, self).__init__(formdata, obj, prefix, **kwargs) 
     questions = kwargs['questions'] 
     // How to to dynamically create three questions formatted as below? 

    question = RadioField(
      # question ?, 
      [Required()], 
      choices = [('yes', 'Yes'), ('no', 'No')], 
      ) 

questions = ("Do you like peas?", "Do you like tea?", "Are you nice?") 
form = VariableForm(questions = questions) 

Answer 1

Es war in the docs die ganze Zeit.

def my_view(): 
    class F(MyBaseForm): 
     pass 

    F.username = TextField('username') 
    for name in iterate_some_model_dynamically(): 
     setattr(F, name, TextField(name.title())) 

    form = F(request.POST, ...) 
    # do view stuff 

Was habe ich nicht erkennen, ist, dass die Klassenattribute müssen vor jede Instanziierung auftritt eingestellt werden. Die Klarheit kommt davon :

This is not a bug, it is by design. There are a lot of problems with adding fields to instantiated forms - For example, data comes in through the Form constructor.

If you reread the thread you link, you'll notice you need to derive the class, add fields to that, and then instantiate the new class. Typically you'll do this inside your view handler.

Answer 2

Sie haben es fast geschafft:

CHOICES = [('yes', 'Yes'), ('no', 'No')] 

class VariableForm(Form): 

    def __new__(cls, questions, **kwargs): 
     for index, question in enumerate(questions): 
      field_name = "question_{}".format(index) 
      field = RadioField(question, 
            validators=[Required()], 
            choices=CHOICES) 
      setattr(cls, field_name, field) 
     return super(VariableForm, cls).__new__(cls, **kwargs)