Handling request in django inclusion template tag

Question

I am new to Django and am trying to put an upload file form into an inclusion tag. So I can use it in various templates.

I have created the following inclusion tag:

#upload_files.py

@register.inclusion_tag('upload_form.html')
def upload_handler(context):
    request = context['request']
    view_url = reverse('upload.views.upload_handler')
    if request.method == 'POST':
        form = UploadForm(request.POST, request.FILES)
        if form.is_valid():
            form.save()
        return HttpResponseRedirect(view_url)

    upload_url, upload_data = prepare_upload(request, view_url)
    form = UploadForm()

    upload_model_list = UploadModel.objects.all().order_by('-pub_date')

I wish to now include this in a template, so on the page I have:

#mypage.html
{% extends 'base.html' %}
{% load upload_files %}

{% upload_handler %}

I get the following error:

upload_handler takes 1 arguments

What argument should I be passing from the template?

Answer 1

You need to add takes_context=True when registering the tag to get django pass the context object to the function:

@register.inclusion_tag('upload_form.html', takes_context=True)

Per default context will always be the first argument then!

For further details see django's documentation on inclusion tags.

A side note: Decide carefully on what pages you use this template tag on, because a view may render additional forms/handle post requests in a certain way that might collide with the logic your tag provides (eg. the form validation will be triggered if the page may be called by a post request coming from another form). You could eg. additionally check if some HTML element's name is in request.POST if you have multiple forms on a page!