Can't save data when posting form in Django

Question

I'm following a Django tutorial to build a small site which you can add pages and category in the site, I defined a Page model as below:

class Page(models.Model):
    category = models.ForeignKey(Category, on_delete=models.CASCADE)
    title = models.CharField(max_length=128)
    url = models.URLField()
    views = models.IntegerField(default=0)

    def __str__(self):
        return self.title

and defined a modelform as below:

class PageForm(forms.ModelForm):
    title = forms.CharField(max_length=128, help_text="Please enter the title of this page")
    url = forms.URLField(max_length=200, help_text="Please enter the URL of the page")
    views = forms.IntegerField(widget=forms.HiddenInput(),initial=0)
    category = forms.ModelChoiceField(queryset=Category.objects.all(),help_text="Please choose a category for the page")

    class Meta:
        model = Page
        fields = '__all__'

and views to add_page is:

def add_page(request):

     if request.method == 'POST':
        form = PageForm(request.POST)

        if form.is_valid():
           page = form.save(commit=True)
           print(page)
           page.views = 0
           page.save()
           return index(request)
        else:
           print('error')
           form.errors
    else:
        form = PageForm()
        context_dict = {'form':form}

    return render(request,'rango/add_page.html',context_dict)

But when I run the site and fill the information like this in the field:

choose category 'HTML' in the select window
fill 'w3c' in the name field
fill 'http://www.w3cshools.com' in the url field

and choose to 'create a page' but there's no response after clicking the button nor the data in the form is added into the database, I try to debug using print and found that the data can't pass through the validation which no process of the if block 'form.is_valid()' but I can't understand why and how to da modification.

my category model is defined as:

class Category(models.Model):
    name = models.CharField(max_length=128, unique=True)
    views = models.IntegerField(default=0)
    likes = models.IntegerField(default=0)
    slug = models.SlugField(unique=True)

    def save(self,*args,**kwargs):
        self.slug = slugify(self.name)
        super(Category, self).save(*args,**kwargs)

    def __str__(self):
        return self.name

category form:

class CategoryForm(forms.ModelForm):
    name = forms.CharField(max_length=128, help_text="Please enter the category name.")
    views = forms.IntegerField(widget=forms.HiddenInput(),initial=0)
    likes = forms.IntegerField(widget=forms.HiddenInput(),initial=0)
    slug = forms.CharField(widget=forms.HiddenInput(),required=False)

    class Meta:
        model = Category
        fields = ('name',)

So a title, category, url and views get filled out in a form and posted? Not sure I would name a field views, by the way, as that might result in a naming conflict. — Matt Cremeens, May 11 '17 at 13:33
@Matt Cremeens Yes except that I set the fields 'views' to be hidden. Ok I'll change the name, since I just follow the tutorial I didn't pay much attention to the naming convention. — NullPointer, May 11 '17 at 13:40
@Matt Cremeens No error message is printed in the terminal. So I can't proceed for debugging. — NullPointer, May 11 '17 at 13:56
@Matt Cremeens I used to add a print('ok') statement in the if form.is_valid() block but nothing print out, so I guess not. — NullPointer, May 11 '17 at 14:05
Then I would think that `print form.errors` would print something. I notice you don't actually have a print statement in front of `form.errors` in your code. — Matt Cremeens, May 11 '17 at 14:07
@Matt Cremeens You're right, there're some errors with the tutorial, I add a print function in front of form.errors and it say "Not Found: /favicon.ico [11/May/2017 14:09:39] "GET /favicon.ico HTTP/1.1" 404 2343 error
views
This field is required.
[11/May/2017 14:09:41] "POST /rango/add_page/ HTTP/1.1" 200 1404", but I defined the hidden field and it works well with category... — NullPointer, May 11 '17 at 14:14
When you view the source of the form, can you see the hidden input with a value in it? — Matt Cremeens, May 11 '17 at 14:43
Ah, but no value is set for some reason. This appears to be the problem. — Matt Cremeens, May 11 '17 at 14:46
@Matt Cremeens Yeah you are right, but I set an initial value to 0 as I defined the page form, strange... — NullPointer, May 11 '17 at 14:49
Can you change views to be a `CharField` instead of `IntegerField`. I wonder if since what you are posting is from an `input` tag if it's coming through a text and not an integer. Change it in both the form and the model. — Matt Cremeens, May 11 '17 at 15:12

score 0 · Answer 1 · edited May 23 '17 at 12:26

0

Instead of setting initial like you have here

views = forms.IntegerField(widget=forms.HiddenInput(),initial=0)

Just use this

views = forms.IntegerField(widget=forms.HiddenInput())

and then change this

form = PageForm(request.POST)

to this

form = PageForm(request.POST, initial={"views": "0"})

I am referring to this post.

edited May 23 '17 at 12:26

Community

1
1

answered May 11 '17 at 15:15

Matt Cremeens

4,951
7
38
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Still dose not work, and same with the CharField, but I defined category form in the same manner as page, it works. I'll add category form in the problem statement. – NullPointer May 11 '17 at 15:35
Also post your template, please. – Matt Cremeens May 11 '17 at 15:37
I upload the code to the github page, and add the links in the last line of the problem statement. Please check, and thanks for your patience. – NullPointer May 11 '17 at 15:52
`forms.py` in your git repository isn't matching your code here. In `PageForm` you have `fields = ('title','url','category')`. What happens if you add `views` to that tuple? – Matt Cremeens May 11 '17 at 18:36
Yes when I try to paste my Category view here and it occured to me that maybe I shouldn't include hidden fields in the meta description, but after I change that it still didn't work. – NullPointer May 12 '17 at 13:06

score 0 · Answer 2 · answered May 18 '17 at 12:32

0

Just exclude field 'category' in the PageForm and restart server can work.

answered May 18 '17 at 12:32

NullPointer

412
7
17

score 0 · Answer 3 · answered May 18 '17 at 12:48

Change your view like this,

def add_page(request): 
    if request.method == 'POST': 
        form = PageForm(request.POST)
        if form.is_valid(): 
            page = form.save(commit=False)
            page.views = 0 
            page.save()
            return redirect('index') 
        else: 
            render(request, 'rango/add_page.html', {'form':'form.errors'}
    else: 
        form = PageForm()
    context_dict = {'form':form}
    return render(request,'rango/add_page.html',context_dict)

You should put commit=False, when saving the form, for adding additional data.

Can't save data when posting form in Django

3 Answers3