The Post could not be created because the data didn't validate - ( When i set past time in form field )

问题

I am building a BlogApp and I am stuck on an Error and I keep getting this error :-

The Post could not be created because the data didn't validate.

What i am trying to do

I made a feature that users cannot insert past date in DateTimeField. AND If user enters the past date in field then a Validation Error should be display. AND i was testing it and suddenly a new error is occured.

forms.py

class PostForm(forms.ModelForm):
    date = forms.DateTimeField(initial=timezone.now)

    def clean_date(self):
            date = self.cleaned_data['date']
            if date.date() < datetime.date.today():
                raise forms.ValidationError("The date cannot be in the past!")
            return date

views.py

def new__blog_post(request,user_id):

    if request.method != 'POST':
        form = PostForm()
    else:
        form = PostForm(request.POST,request.FILES)
        new_post = form.save()
        new_post.post_owner = request.user
        new_post.save()
        return redirect('mains:posts',user_id=user_id)

    context = {'form':form,'posts':posts}
    return render(request, 'new_blog_post.html', context)

models.py

class BlogPost(models.Model):
    post_owner = models.ForeignKey(User,default='',null=True,on_delete = models.CASCADE)
    post_title = models.CharField(max_length=500,default='')
    date_added = models.DateTimeField(null=True,default=timezone.now)

It is showing that the Error is in new_post = form.save() line . It means that there's having problem in saving form.

The Problem

When i set the time of now ( as timezone.now as default ) in DateTimeField then it is working fine , Post is saving fine. BUT when i change the present time (2021-02-18) into past time (2019-02-18) then it is showing that error The Post could not be created because the data didn't validate .

I don't know what am i doing wrong

Any help would be appreciated.

Thank You in Advance

回答1:

To validate data you need to call Form.is_valid(). See Using forms to validate data.

So call first is_valid():

def new__blog_post(request,user_id):
    if request.method == 'POST':
        form = PostForm(request.POST,request.FILES)
        if form.is_valid():
            new_post = form.save()
            new_post.post_owner = request.user
            new_post.save()
            return redirect('mains:posts',user_id=user_id)
    else:
         form = PostForm()

    context = {'form':form}
    return render(request, 'new_blog_post.html', context)

The name of clean method must be changed - forms.py:

from django.core.exceptions import ValidationError
import datetime

class PostForm(forms.ModelForm):
    class Meta:
        model = BlogPost
        fields = ["post_title","date_added"]

    def clean_date_added(self):
        date_added = self.cleaned_data['date_added']
        if date_added.date() < datetime.added.today():
            raise forms.ValidationError("The date cannot be in the past!")
        return date_added

来源：https://stackoverflow.com/questions/66265246/the-post-could-not-be-created-because-the-data-didnt-validate-when-i-set-pa