How to add the current query string to an URL in a Django template?

To capture the QUERY_PARAMS that were part of the request, you reference the dict that contains those parameters (request.GET) and urlencode them so they are acceptable as part of an href. request.GET.urlencode returns a string that looks like ds=&date_published__year=2008 which you can put into a link on the page like so:

<a href="sameLink/?{{ request.GET.urlencode }}">

If you register a templatetag like follows:

@register.simple_tag
def query_transform(request, **kwargs):
    updated = request.GET.copy()
    updated.update(kwargs)
    return updated.urlencode()

you can modify the query string in your template:

<a href="{% url 'view_name' %}?{% query_transform request a=5 b=6 %}">

This will preserve anything already in the query string and just update the keys that you specify.

I found that @Michael's answer didn't quite work when you wanted to update an existing query parameter.

The following worked for me:

@register.simple_tag
def query_transform(request, **kwargs):
    updated = request.GET.copy()
    for k, v in kwargs.items():
        updated[k] = v

    return updated.urlencode()