Django FormMixin does not render Form

Question

I had following FormView which worked for what I wanted to do back then:

class LearningObjectiveView( LoginRequiredMixin, FormView ):
  form_class = LearningObjectiveForm
  template_name = 'learningobjective'
  success_url = reverse_lazy( 'learning_objective' )

  def get_context_data( self, **kwargs ):
    trainee = Trainee.objects.get( user = self.request.user )
    context = super( LearningObjectiveView, self ).get_context_data( **kwargs )
    context['learningobjective'] = LearningObjective.objects.filter( trainee = trainee.id )
    context['topic'] = Topic.objects.filter( trainee = trainee.id )
    return context

  def get_form_kwargs( self ):
    kwargs = super( LearningObjectiveView , self ).get_form_kwargs()
    kwargs['user'] = self.request.user
    return kwargs 

  def form_valid( self, form ):
    self.object = form.save( commit = False )
    if self.request.user.is_authenticated():
      self.object.trainee = Trainee.objects.get( user = self.request.user )
    self.object.save()
    form.save_m2m()
    return super( LearningObjectiveView, self ).form_valid( form )

Since I want to include pagination now and I just saw example on every CBV but the FormView, I wanted to use a ListView with a FormMixin.

ListView with FormMixin

class LearningObjectiveView( LoginRequiredMixin, FormMixin, ListView ):
  form_class = LearningObjectiveForm
  template_name = 'learningobjective'
  model = LearningObjective
  success_url = reverse_lazy( 'learning_objective' )

  def get_context_data( self, **kwargs ):
    trainee = Trainee.objects.get( user = self.request.user )
    context = super( LearningObjectiveView, self ).get_context_data( **kwargs )
    context['learningobjective'] = LearningObjective.objects.filter( trainee = trainee.id )
    context['topic'] = Topic.objects.filter( trainee = trainee.id )
    return context

  def get_form_kwargs( self ):
    kwargs = super( LearningObjectiveView , self ).get_form_kwargs()
    kwargs['user'] = self.request.user
    return kwargs 

  def form_valid( self, form ):
    self.object = form.save( commit = False )
    if self.request.user.is_authenticated():
      self.object.trainee = Trainee.objects.get( user = self.request.user )
    self.object.save()
    form.save_m2m()
    return super( LearningObjectiveView, self ).form_valid( form )

Apparently this only renders the context data but not the form I want to use. Do you know how to solve this problem.

score 2 · Accepted Answer · answered Mar 24 '15 at 15:41

2

FormMixin doesn't do what you think it does. All it does is provide methods for getting and instantiating the form; it doesn't add it to the context, nor does it deal with validating and saving it on submission.

You might want to use ProcessFormView instead - as the docs state, despite the name this is really a mixin. However you should also bear in mind the warning on the mixins documentation against trying to mix together mixins or views from different generic groups.

answered Mar 24 '15 at 15:41

Daniel Roseman

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Thank you very much for your answer. Despite of that, can you please tell me how you would program a solution for this approach. ( Paginated list and form on the same site ). Better practices and solutions are welcomed :) – ZedsWhatSheSaid Mar 24 '15 at 15:56

Django FormMixin does not render Form

1 Answers1