Django execute previous action on refresh-CodePudding

I have tried to add a book in to the database using an HTML form. After the submission, the page redirect to a page where all the books are listed .Then whenever I refresh the page , the data is became duplicated. How do I resolve this problem?

urls.py

from django.urls import path
from . import views
app_name='library'
urlpatterns =[
    path('', views.home, name='home'),
    path('book/',views.book,name='book'),
    path('book_details/<int:book_id>',views.book_details,name='book_details'),
    path('book_edit/<int:book_id>',views.book_edit,name='book_edit'),
    path('book_delete/<int:book_id>',views.book_delete,name='book_delete'),
    path('update/<int:book_id>',views.update,name='update'),
    path('author/',views.author_view,name='author_view'),
    path('addbook/',views.add_book,name='add_book'),
    path('books/',views.add_submit,name='add_submit'),
    
]

views.py


def add_submit(request): 
    if request.method =='POST':
        title=request.POST.get('t_title')
        print(title)
        author_name=request.POST.get('a_author')
        author, created=Author.objects.get_or_create(Name=author_name)
        summary=request.POST.get('s_summary')
        date=request.POST.get('d_date')
        book=Book(Title=title,Author=author,Summary=summary,Published_date=date)
        book.save()
        books=Book.objects.all()

        return render(request,'books.html',{'books':books})

Template file:

<form action="{% url 'library:add_submit'  %}" method="POST">
            {% csrf_token %}
        
            
            <div >
              <input type="text" id="bname" name="t_title"  />
              <label    for="bname">Title</label>
            </div>
          
           
            <div >
              <input type="text" id="bauthor" name="a_author"  />
              <label   for="bauthor">Author</label>
            </div>

            <div >
                <textarea  rows="5" cols="33" id="bsummary"  name="s_summary" ></textarea>
                <label  for="bsummary">Summary</label>
              </div>

              <div >
                <input type="date" placeholder="" id="pdate" name="d_date"  />
                <label  for="pdate">Published_Date</label>
              </div>
          
          
          
            <!-- Submit button -->
            <button type="submit" >SUBMIT</button>
          </form>

CodePudding user response：

This is most common problem, the thing is that after dealing with POST data you should always return an HttpResponseRedirect, the tip is not specific to Django, but it's a good web practice in general so:

urls.py:

urlpatterns =[
    ...
    path("success/", views.success, name="success"
    
]

views.py:

def add_submit(request): 
    if request.method =='POST':
        title=request.POST.get('t_title')
        print(title)
        author_name=request.POST.get('a_author')
        author, created=Author.objects.get_or_create(Name=author_name)
        summary=request.POST.get('s_summary')
        date=request.POST.get('d_date')
        book=Book(Title=title,Author=author,Summary=summary,Published_date=date)
        book.save()
        return redirect("library:success")

    else:
        books=Book.objects.all()

    return render(request,'books.html',{'books':books})

def success(request):
    return render("success.html")

success.html

<h2> The form has been successfully submitted.</h2>

<a href="{% url 'library:add-submit' %}"> Go back to form</a>