Django form.is_valid() 返回 false

Question

I am trying to update an instance from Author table, But form.is_valid returning false always.

I have added enctype="multipart/form-data" in the template form, In the views im getting files also, but form is not validating.

Am I missing anything?

This is views section.

def update(request,something,id):
something=str(something).lower()
if something=='author':
    author=Author_model.objects.get(id=id)
    if request.method=='GET':
        return render(request,'update_author.html',{'author':author})
    else:
        form = Author_form(request.POST, request.FILES,instance=author)
        print('form.is_valid()',form.is_valid())
        if form.is_valid():
            image_path = author.image_document.path
            if os.path.exists(image_path):
                os.remove(image_path)
            form.save()
        return redirect('http://127.0.0.1:8000/bookdb/author/')

This is a template.

<form action="" method="post" enctype="multipart/form-data">
        <center>
            <h2>Update Author</h2><hr>
            <table>
                <tr>
                    <td>Solutation </td>
                    <td>: <select name="" id="">
                        <option value="{{author.solutaion}}">{{author.solutaion}}</option>
                        <option value="Mr">Mr</option>
                        <option value="Ms">Ms</option>
                        <option value="Dr">Dr</option>
                    </select></td>
                </tr>
                <tr><td >Name </td>
                <td>: <input type="text" value="{{author.name}}"></td></tr>
                <tr>
                    <td>Email </td>
                    <td>: <input type="email" value="{{author.email}}"></td>
                </tr>
                <tr>
                    <td>Headshot {{author.headshot}}</td>
                    <td><img src="{{author.headshot.url}}" alt="Image not found" width="100" height="60"></td>
                    <td>: <input type="file"></td>
                </tr>
            </table><br>
            <button type="submit">Submit</button>
        </center>
        {%csrf_token%}
    </form>

Author Form:

class Author_form(ModelForm):
required_css_class='required'
class Meta:
    model=Author_model
    fields='__all__'

Author model:

class Author_model(models.Model):
solutaion=models.CharField(max_length=10)
name=models.CharField(max_length=30)
email=models.EmailField(blank=True)
headshot=models.ImageField(upload_to='imgs')
def __str__(self):
    return self.name

Urls.py

from django.contrib import admin
from django.urls import path
from model_app import views as v
from django.contrib.staticfiles.urls import staticfiles_urlpatterns
from django.conf import settings
from django.conf.urls.static import static

urlpatterns = [
    path('admin/', admin.site.urls),
    path('bookdb/<something>/',v.show_something),
    path('publishers/<name>/',v.a_publisher),
    path('publishers/<name>/<id>/',v.req_cols),
    path('books/',v.books),
    path('books/<name>/',v.book),
    path('book_one/<title>/',v.book_one),
    path('book_with_publisher/<title>/<pub>/',v.book_with_publisher),
    path('Add/<someone>/',v.user_form),
    path('delete/<something>/<id>/',v.delete_item),
    path('update/<something>/<id>/',v.update)
]
urlpatterns += staticfiles_urlpatterns()

if settings.DEBUG:
    urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

Answer 1

You have customize your form inputs so they can not match with your form fields in server-side!
So form_valid() is always False .
I update your template:

  <form action="" method="post" enctype="multipart/form-data">
            <center>
                <h2>Update Author</h2><hr>
                <table>
                    <tr>
                        <td>Solutation </td>
                        <td>: <select name="solutaion" id="" >
                            <option value="{{author.solutaion}}">{{author.solutaion}}</option>
                            <option value="Mr">Mr</option>
                            <option value="Ms">Ms</option>
                            <option value="Dr">Dr</option>
                        </select></td>
                    </tr>
                    <tr><td >Name </td>
                    <td>: <input type="text" value="{{author.name}}" name="name"></td></tr>
                    <tr>
                        <td>Email </td>
                        <td>: <input type="email" value="{{author.email}}" name="email"></td>
                    </tr>
                    <tr>
                        <td>Headshot {{author.headshot}}</td>
                        <td><img src="{{author.headshot.url}}" alt="Image not found" width="100" height="60"></td>
                        <td>: <input type="file" name="headshot"></td>
                    </tr>
                </table><br>
                <button type="submit">Submit</button>
            </center>
            {%csrf_token%}
        </form>

Also take a look at your browser DevTools in order to make sure their values before you get a request.

Answer 2

Since you are using custom html so you need to set name attributes of your html according to the field name of your model. So form.is_valid() always returns False if the name attribute is different or have not mentioned.

<form action="/update/author/{{author.id}}" method="post" enctype="multipart/form-data"> #<--- Here I set `author` in place of `something` add values accordingly
    <center>
        <h2>Update Author</h2><hr>
        <table>
            <tr>
                <td>Solutation </td>
                <td>: <select name="solutaion" id="">
                    <option value="{{author.solutaion}}">{{author.solutaion}}</option>
                    <option value="Mr">Mr</option>
                    <option value="Ms">Ms</option>
                    <option value="Dr">Dr</option>
                </select></td>
            </tr>
            <tr><td >Name </td>
            <td>: <input type="text" name="name" value="{{author.name}}"></td></tr>
            <tr>
                <td>Email </td>
                <td>: <input type="email" name="email" value="{{author.email}}"></td>
            </tr>
            <tr>
                <td>Headshot {{author.headshot}}</td>
                <td><img src="{{author.headshot.url}}" alt="Image not found" width="100" height="60"></td>
                <td>: <input type="file" name="headshot"></td>
            </tr>
        </table><br>
        <button type="submit">Submit</button>
    </center>
    {%csrf_token%}
</form>

Answer 3

Could you show your form class? In the case the problem is with form validation, it's important to share.