Django xhtml2pdf 'HttpResponse' does not have the buffer interface

Question

I'm trying and making some tests for outputting pdfs with Django. I'm using the xhtml2pdf project installed with pip.

I looked at an example for sending a pdf to the browser and succedeed, but when trying with a template of mine, an error appears. It reads:

'HttpResponse' does not have the buffer interface

My view code is next:

def generate_pdf(request):

    from xhtml2pdf import pisa
    from person.views import alumn_list

    html = alumn_list(request, 12, 0) # This function returns a render('alumn_list.html)

    pdfFile = open(os.path.join(base.TEMPLATE_DIRS[0], 'test.pdf'), 'w+b')
    pisaStatus = pisa.CreatePDF(html, dest=pdfFile) # The errors happens here

    pdfFile.seek(0)
    pdf = pdfFile.read()
    pdfFile.close()
    return HttpResponse(pdf, content_type='application/pdf')

My template is next:

{% extends "alumns.html" %}
{% load i18n %}

{% block extra_css %}
    <style>
    @page {
        size: letter portrait;
        @frame header_frame {           /* Static frame */
            -pdf-frame-content: header_content;
            left: 50pt; width: 512pt; top: 50pt; height: 40pt;
        }
        @frame col1_frame {             /* Content frame 1 */
            left: 44pt; width: 445pt; top: 90pt; height: 632pt;
            text-align:center;
        }

        @frame footer_frame {           /* Static frame */
            -pdf-frame-content: footer_content;
            left: 50pt; width: 512pt; top: 772pt; height: 20pt;
        }
    }
    </style>
{% endblock extra_css %}

{% block title %}
    {% trans "Alumn list" %}
{% endblock title %}

{% block page_title %}
    {% trans "Alumn list" %}
{% endblock page_title %}

{% block content %}
    <table class="infoTable">
        {% csrf_token %}
        {% for index in "12" %}
        <caption {% ifequal index "2" %}align="bottom"{% endifequal%}>
            <a href="{{hrefs.0}}" class="pager">&lt;&lt; {% trans "Previous" %}</a>
            <a href="{{hrefs.1}}" class="pager">{% trans "Next" %} &gt;&gt;</a>
        </caption>
        {% endfor %}

        <thead>
            <th>{% trans "ID" %}</th>
            <th>{% trans "Name" %}</th>
        </thead>
    {% for alumn in alumnList %}
        <tr id="alumn{{alumn.alumnId}}">
            <td>{{ alumn.alumnId }}</td>
            <td><button class="profileAlumn" alumn_id="{{alumn.alumnId}}">{% trans "Profile" %}</button></td>
            <td><button class="deleteAlumn" alumn_id="{{alumn.alumnId}}">{% trans "Delete" %}</button></td>
        </tr>
    {% endfor %}
    </table>
{% endblock content %}

I don't know how to mend this bug. I googled for this error but only three ambiguous pages of results appeared, none making reference to HttpResponse.

Please help. I don't know what I'm doing wrong.

It would help me also if someone has some link where I can learn how to make a pdf from every rendered HTML template from my webapp.

Thanks very much in advance

Answer 1

alumn_list is a view. So it returns an HttpResponse object. But you need to pass a byte string to pisa.CreatePDF which is response's content. So you could do the following:

pisaStatus = pisa.CreatePDF(html.content, dest=pdfFile)