How to Retrieve the Next Parameter From a URL in Django

In this article, we show how to retreive the next parameter from a URL in Django.

The next parameter appears in a URL when a user is trying to get to a page but is redirected to another page first before being able to access that page. This may occur such as when a view requires a login through a login_required decorator.

Before a user can do something on the site, such as create a post, s/he may have to be logged in. Thus, if a user who isn't logged in clicks on a 'Create a Post' link, s/he will first be directed to the login page. Once logged in, s/he then is redirected to the 'Create a Post' page.

The next parameter in a URL exists so that we can extract this value and redirect a user to this page once logged in.

So how do we retrieve the next parameter from a URL in Django?

So basically if we try to access a page that requires a login, then it's the login page that will have the next parameter in the URL. Therefore, on this login page, we want to write code so that we can retrieve the next parameter from the URL.

A common technique that is done is to place a hidden field within the login form. Through this hidden field, we can extract the value of the next parameter from the URL and send it to the views.py file to do whatever we want with this next parameter (normally we redirect the user based on this parameter, which is the purpose of the next parameter).

So in the Login.html template file, we will add a hidden field. We'll call the hidden field, next, and we set the value attribute of the hidden field to {{request.GET.next}}

This is shown below.

<h1>Login Page</h1> <form action="" method="POST"> {% csrf_token %} {% if error %} {{ error }} {% endif %} {{ form.as_p }} { <input type="hidden" name="next" value="{{ request.GET.next }}"/> <input type="submit" name="submit" value="Log in"/> </form>

So this is a very basic page.

It contains a header that says Login Page.

And then it has a form that uses the method of POST. It must contain {% csrf_token %} to prevent cross site request forgery. It also must have a way of showing errors, primarily if the username and password are not correct. We then import the login form from the views.py page, which was originally created in the forms.py file. This form just has 2 fields, username and password.

To this form, we add a hidden field. We make the field hidden because we don't want the user to see it. The field serves only to obtain the next parameter in the URL. Therefore, we set the type to "hidden". We set the name to "next". And we set the value of the hidden field to request.GET.next. This retrieves the value of the next parameter in the URL.

Now that we have this, we can move on to the views.py file.

views.py File

So let's now we go to the views.py file.

Within the view for the login page, to get the value of the next parameter, we create a variable and set it equal to, request.POST.get('next')

In the example code below, I created the variable, valuenext.


#views.py File valuenext= request.POST.get('next')

Since this hidden field is an HTML field and not a Django field, we obtain it through the HTML way of using, request.POST.get()

If there is a next parameter, this variable will have data. If there is no next parameter, this variable will be empty. You can use if statements to determine whether there is a next parameter or not based on this. This is important because you need to know whether you have to redirect a user based on the next parameter once the user logs in successfully.

To see how to redirect a user to a page based on the next parameter from a URL, see the following link: How to Redirect a User After Login to the URL in the next parameter in Django.

And this is how to retrieve the next parameter from a URL in Django.

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