如何根据FK字段验证Django表单字段

Question

我试图创建一个验证规则，如果（里程碑）对象target_date大于项目target_date，则传递错误。问题是没有提出任何错误。

对于纯朴的缘故，

models.py

class Project(models.Model): 
    target_date = models.DateField() 

class Milestone(models.Model): 
    project = models.ForeignKey(Project) 
    target_date = models.DateField() 

Forms.py

class MilestoneAddForm(forms.ModelForm): 

    class Meta: 
     model = Milestone 

    def clean_target_date(self): 
     tdate = self.cleaned_data['target_date'] 
     if tdate > self.instance.project.target_date 
      raise forms.ValidationError("Target Date is outside or project target date.") 
     return tdate 

views.py（丢弃无关的代码）

def MilestoneManage(request, project_id): 
    qs = Project.objects.none() 
    if request.method == 'POST': 
     formset = MilestoneFormSet(request.POST, prefix='new') 
     if formset.is_valid(): 
      newMiles = formset.save(commit=False) 
      for new in newMiles: 
       new.project_id = project.id 
       new.save() 
      return HttpResponseRedirect(reverse('project.views.detail', args=(project.id,))) 
    else: 
     formset = MilestoneFormSet2(queryset=qs, prefix='new') 
    return render_to_response('project/manageMilestones.html', { 
     'formset': formset, 
    }, context_instance=RequestContext(request)) 

Answer 1

这应该工作。有关更改内容的更多信息，请参阅行内注释。

def clean_target_date(self): 
    #     V-- typo (cleand_data => cleaned_data) 
    tdate = self.cleaned_data['target_date'] 
    project = self.instance.project 
    # project allows for nulls, so check that first. 
    if project is None: 
     raise forms.ValidationError("There's no project associated with this milestone.") 
    #     V-- Do an attribute lookup, don't use the query lookup syntax 
    if tdate > project.target_date: 
     raise forms.ValidationError("Target Date is outside or project target date.") 
    return tdate