How to paginate Django with other get variables?

Question

I am having problems using pagination in Django. Take the URL below as an example:

http://127.0.0.1:8000/users/?sort=first_name

On this page I sort a list of users by their first_name. Without a sort GET variable it defaults to sort by id.

Now if I click the next link I expect the following URL:

http://127.0.0.1:8000/users/?sort=first_name&page=2

Instead I lose all get variables and end up with

http://127.0.0.1:8000/users/?page=2

This is a problem because the second page is sorted by id instead of first_name.

If I use request.get_full_path I will eventually end up with an ugly URL:

http://127.0.0.1:8000/users/?sort=first_name&page=2&page=3&page=4

What is the solution? Is there a way to access the GET variables on the template and replace the value for the page?

I am using pagination as described in Django's documentation and my preference is to keep using it. The template code I am using is similar to this:

{% if contacts.has_next %}
    <a href="?page={{ contacts.next_page_number }}">next</a>
{% endif %}

Answer 1

In your views.py you will somehow access the criteria on which you sort, e.g. first_name. You'll need to pass that value to the template and insert it there to remember it.

Example:

{% if contacts.has_next %}
    <a href="?sort={{ criteria }}&page={{ contacts.next_page_number }}">next</a>
{% endif %}

Answer 2

After some playing around I found a solution... although I don't know if it's really a good one. I'd prefer a more elegant solution.

Anyway I pass the request to the template and am able to access all the GET variables via request.GET. Then I loop through the GET dictionary and as long as the variable isn't page I print it.

{% if contacts.has_previous %}
    <a href="?page={{ contacts.previous_page_number }}{% for key,value in request.GET.items %}{% ifnotequal key 'page' %}&{{ key }}={{ value }}{% endifnotequal %}{% endfor %}">previous</a>
{% endif %}

<span class="current">
    Page {{ contacts.number }} of {{ contacts.paginator.num_pages }}.
</span>

{# I have all of this in one line in my code (like in the previous section), but I'm putting spaces here for readability.  #}
{% if contacts.has_next %}
    <a href="?page={{ contacts.next_page_number }}
        {% for key,value in request.GET.items %}
            {% ifnotequal key 'page' %}
                &{{ key }}={{ value }}
            {% endifnotequal %}
        {% endfor %}
    ">next</a>
{% endif %}

Answer 3

Every such link you put in your view has to be equipped with relevant parameters. There is no implicit magic that would convert:

http://127.0.0.1:8000/users/?page=2

into:

http://127.0.0.1:8000/users/?sort=first_name&page=2

So what you need is some Sorter object/class/function/snippet (whatever might fit here without overdoing it), that would act similarly to django.core.paginator.Paginator, but would handle sort GET parameter.

It could be as simple as this:

sort_order = request.GET.get('sort', 'default-criteria')

<paginate, sort>

return render_to_response('view.html', {
    'paginated_contacts': paginated_contacts,  # Paginator stuff
    'sort_order': sort_order if sort_oder != 'default-criteria' else ''
})

Then, in your view:

{% if contacts.has_next %}
    <a href="?page={{ contacts.next_page_number }}{%if sort_order%}&sort={{sort_oder}}{%endif%}">next</a>
{% endif %}

I could be made more generic, but I hope you get the concept.

Answer 4

There is a template tag available at Django snippets for this purpose: http://www.djangosnippets.org/snippets/1627/ Hope it helps ...