Add a plugin API for ticket outputs

src/pretix/plugins/ticketoutputpdf/ticketoutput.py

@@ -0,0 +1,86 @@
+from io import BytesIO
+import logging
+from django.contrib import messages
+from django.contrib.staticfiles import finders
+from django.http import HttpResponse
+from django.shortcuts import redirect
+from django.utils.timezone import now
+from django.utils.translation import ugettext_lazy as _
+from pretix.base.models import Order
+
+from pretix.base.ticketoutput import BaseTicketOutput
+
+
+logger = logging.getLogger('pretix.plugins.ticketoutputpdf')
+
+
+class PdfTicketOutput(BaseTicketOutput):
+
+    identifier = 'pdf'
+    verbose_name = _('PDF output')
+    download_button_text = _('Download PDF')
+    download_button_icon = 'fa-print'
+
+    def generate(self, request, order):
+        from reportlab.graphics.shapes import Drawing
+        from reportlab.pdfgen import canvas
+        from reportlab.lib import pagesizes, units
+        from reportlab.graphics.barcode.qr import QrCodeWidget
+        from reportlab.graphics import renderPDF
+        from PyPDF2 import PdfFileWriter, PdfFileReader
+
+        response = HttpResponse(content_type='application/pdf')
+        response['Content-Disposition'] = 'inline; filename="order%s%s.pdf"' % (request.event.slug, order.code)
+
+        pagesize = request.event.settings.get('ticketpdf_pagesize', default='A4')
+        if hasattr(pagesizes, pagesize):
+            pagesize = getattr(pagesizes, pagesize)
+        else:
+            pagesize = pagesizes.A4
+        defaultfname = finders.find('pretixpresale/pdf/ticket_default_a4.pdf')
+        fname = request.event.settings.get('ticketpdf_background', default=defaultfname)
+        # TODO: Handle file objects
+
+        buffer = BytesIO()
+        p = canvas.Canvas(buffer, pagesize=pagesize)
+
+        for op in order.positions.all().select_related('item', 'variation'):
+            p.setFont("Helvetica", 22)
+            p.drawString(15 * units.mm, 235 * units.mm, str(request.event.name))
+
+            p.setFont("Helvetica", 17)
+            item = str(op.item.name)
+            if op.variation:
+                item += " – " + str(op.variation)
+            p.drawString(15 * units.mm, 220 * units.mm, item)
+
+            p.setFont("Helvetica", 17)
+            p.drawString(15 * units.mm, 210 * units.mm, "%s %s" % (str(op.price), request.event.currency))
+
+            reqs = 80 * units.mm
+            qrw = QrCodeWidget(op.identity, barLevel='H')
+            b = qrw.getBounds()
+            w = b[2] - b[0]
+            h = b[3] - b[1]
+            d = Drawing(reqs, reqs, transform=[reqs / w, 0, 0, reqs / h, 0, 0])
+            d.add(qrw)
+            renderPDF.draw(d, p, 10 * units.mm, 130 * units.mm)
+
+            p.setFont("Helvetica", 11)
+            p.drawString(15 * units.mm, 130 * units.mm, op.identity)
+
+            p.showPage()
+
+        p.save()
+
+        buffer.seek(0)
+        new_pdf = PdfFileReader(buffer)
+        output = PdfFileWriter()
+        for page in new_pdf.pages:
+            bg_pdf = PdfFileReader(open(fname, "rb"))
+            bg_page = bg_pdf.getPage(0)
+            bg_page.mergePage(page)
+            output.addPage(bg_page)
+
+        output.write(response)
+        return response