Django CreateView顯示錯誤不起作用

Question

如果我嘗試在此日期之間的一段時間內租用這輛車，如何防止重復租用該車（例如，01/01/2017至01/03/2017）？ 2017年1月1日至2017年3月1日”，它應該給我一個錯誤，例如字段右側的驗證錯誤

我的租車應用程序的屏幕截圖

models.py

class Car(models.Model):

    imatriculation = models.CharField(max_length=100, primary_key=True)
    marque = models.CharField(max_length=100)
    couleur = models.CharField(max_length=100)

class Contra(models.Model):

    car = models.ForeignKey(Car, on_delete=models.CASCADE)
    date_debut = models.DateField(null=True ,blank=True)
    heure_debut = models.TimeField(null=True ,blank=True)
    date_retour = models.DateField(null=True ,blank=True)
    heure_retour = models.TimeField(null=True ,blank=True)

forms.py

class CarForm(forms.ModelForm):

    class Meta:
        model = Car
        fields = ('imatriculation', 'marque',  'couleur')       


class ContraForm(forms.ModelForm):

    date_debut = forms.DateField(widget = AdminDateWidget())
    heure_debut = forms.TimeField(widget = AdminTimeWidget())
    date_retour = forms.DateField(widget = AdminDateWidget())
    heure_retour = forms.TimeField(widget = AdminTimeWidget())

    class Meta:
        model = Contra
        fields = ('car','date_debut','heure_debut',  
                 'date_retour','heure_retour')

views.py

class ContraCreate(CreateView):
    template_name = 'rentcar/contra_update.html'
    form_class = ContraForm
    model = Contra

    def form_valid(self, form):
                now_date = date.today()
                now_time = datetime.now().strftime('%H:%M:%S')
                x = Contra.objects.filter(location=self.request.user,
                    date_debut__lte=now_date, date_retour__gte=now_date)
                c = form.instance.car
                for e in x:
                    if c.imatriculation ==  e.car.imatriculation :
                    print ("Leased car")
                    ValidationError(_('Invalid value'))
                    return super(ContraCreate, self).form_invalid(form)
                return super(ContraCreate, self).form_valid(form) 

我找到了使用清潔的解決方案

def clean(self):
    super(ContratForm, self).clean()
    form_car          = self.cleaned_data.get('car')    
    form_date_debut   = self.cleaned_data.get('date_debut')
    form_date_retour  = self.cleaned_data.get('date_retour')
    form_heure_debut  = self.cleaned_data.get('heure_debut')
    form_heure_retour = self.cleaned_data.get('heure_retour')
    h                 = form_car.imatriculation

    x1  = Contrat.objects.filter(location=self.user,car=h ,date_debut__lte=form_date_debut,date_retour__gte=form_date_retour)
    x2  = Contrat.objects.filter(location=self.user,car=h ,date_debut__gt=form_date_debut,date_debut__lt=form_date_retour,date_retour__gte=form_date_retour)
    x25 = Contrat.objects.filter(location=self.user,car=h ,date_debut__gt=form_date_debut,date_debut=form_date_retour,heure_debut__lt=form_heure_retour)
    x3  = Contrat.objects.filter(location=self.user,car=h ,date_debut__lte=form_date_debut,date_retour__gt=form_date_debut,date_retour__lt=form_date_retour)
    x35 = Contrat.objects.filter(location=self.user,car=h ,date_debut__lte=form_date_debut,date_retour=form_date_debut,heure_retour__gt=form_heure_debut)
    x4  = Contrat.objects.filter(location=self.user,car=h ,date_debut__gt=form_date_debut,date_retour__lt=form_date_retour)


    if x1:
        for k in x1:
            self._errors['car']          = "Deja reserve .contrat %s" %(k.id)
            self._errors['date_debut']   = k.date_debut.strftime('%d/%m/%Y')
            self._errors['date_retour']  = k.date_retour.strftime('%d/%m/%Y')
    elif x2:
        for k in x2:
            self._errors['car']          = "Deja reserve .contrat %s" %(k.id)
            self._errors['date_retour']  = ("<= %s" %(k.date_debut).strftime('%d/%m/%Y'))
    elif x25:
        for k in x25:
            self._errors['car']          = "Changer l'heur retour"
            self._errors['date_retour']  = ("= Date depart contrat %s" %(k.id))
            self._errors['heure_retour'] = ("< %s" %(k.heure_debut))
    elif x3:
        for k in x35:
            self._errors['car']          = "Deja reserve .contrat %s" %(k.id)
            self._errors['date_debut']   = (">= %s" %(k.date_retour).strftime('%d/%m/%Y'))
    elif x35:
        for k in x35:
            self._errors['car']          = "Changer l'heur de depart"
            self._errors['date_debut']   = ("= Date debut contrat %s" %(k.id))
            self._errors['heure_debut']  = ("> %s" %(k.heure_retour))
    elif x4:
        for k in x4:
            self._errors['car']          = "Deja reserve .contrat %s" %(k.id)
            self._errors['date_debut']   = k.date_debut.strftime('%d/%m/%Y')
            self._errors['date_retour']  = k.date_retour.strftime('%d/%m/%Y')

    return self.cleaned_data

Answer 1

到視圖中的form_valid調用時，Django已經確定該表單有效。 看看文檔中有關驗證如何工作的內容。

您想要對數據庫中的數據進行額外的驗證，可以通過覆蓋表單中的干凈驗證階段來完成。

基於上述代碼的解決方案如下所示：

def clean(self):
    '''This goes in ContraForm.py'''
    cleaned_data = super(ContraForm, self).clean()
    now_date = date.today()
    now_time = datetime.now().strftime('%H:%M:%S')
    x = Contra.objects.filter(location=self.request.user,
                date_debut__lte=now_date, date_retour__gte=now_date)
    c = form.instance.car
    for e in x:
        if c.imatriculation ==  e.car.imatriculation :
            raise ValidationError('Invalid debut date. Car already reserved.')
    return cleaned_data