Editing data into a model in Django

This will assume you have created a model for 'Products' from the previous tutorial. Also the page to Add data into a model will create the Product Form.

views.py

Now within your app folder we need to use 'views.py' to create a view for our add product form. We need to import your form and a few other functions, so make sure the following are imported:

from .forms import ProductForm
from django.contrib import messages
from django.shortcuts import redirect

If you already have a view to add a product, copy it and each time 'ProductForm' is used we need to pass the instance in the '()' brackets. 'prodID' is also used to get the product ID from the url:

def editproduct(request, prodID):
    if request.method=='POST': # this means the form has data
        form = ProductForm(request.POST,instance=Product.objects.get(pk=prodID)) # get the form and it data
            if form.is_valid(): # check if it is valid
                name = form.cleaned_data.get('name') # clean the data
                manufacturer = form.cleaned_data.get('manufacturer') # clean the data
                description = form.cleaned_data.get('description') # clean the data
                form.save() # save the data to the model
                messages.success(request, 'Your product has been edited!')
                return redirect('\products')
            else: # form not valid so display message and retain the data entered
                form = ProductForm(request.POST,instance=Product.objects.get(pk=prodID))
                messages.success(request, 'Error in editing your product, the form is not valid!')
                return render(request, '/editproduct.html', {'form':form})
    else: #the form has no data
        form = ProductForm(instance=Product.objects.get(pk=prodID)) #produce a blank form
        return render(request, '/editproduct.html', {'form':form})

urls.py

Now in the 'urls.py' file in the project folder we need to add a new urlpattern. So add the following:

path('editproduct/<int:prodID>/', myapp_views.editproduct, name='editproduct'),

editproduct.html

In the 'templates' folder in the 'MyApp' app, create the following 'html' page:

{% extends "MyApp/base.html" %}

{% block content %}
<h2>Edit Product</h2>
<form method="post">
    {% csrf_token %}
    {{ form.as_p }}
    <button type="submit">Submit<button>
</form>
{% endblock %}

Testing

Run your server and visit your webapp, add '/editproduct/1' to the address bar to access your new edit product '1' page.