WTForms創建可變數量的字段

Question

我如何動態地創建幾個帶有不同問題的表單域，但答案相同？

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

這是in the docs一直。

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 

什麼我不知道的是，類屬性必須任何實例發生之前設置。清晰度來自於此bitbucket comment：

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

就快：

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)