My django app is using a multi-frames reportlab pdf report in witch I would like to add some barcodes/qr-codes.
The problem I have is that every object I add to my layout have to be a Flowable. So the question would be as to cast a PlotArea (mother class of QrCodeWidget) as Flowable.
If we have an answer here the error message we can get if we add the QrCodeWidget as
AttributeError: QrCodeWidget instance has no attribute 'getKeepWithNext'
Ok, I made my own Flowable, it was simpler than I taught.
It's as simple as doing it on a canva with this API.
from reportlab.platypus import Flowable
from reportlab.graphics.barcode import qr
from reportlab.graphics import renderPDF
from reportlab.graphics.shapes import Drawing
class QRFlowable(Flowable):
# usage :
# story.append(QRFlowable("http://google.fr"))
def __init__(self, qr_value):
# init and store rendering value
Flowable.__init__(self)
self.qr_value = qr_value
def wrap(self, availWidth, availHeight):
# optionnal, here I ask for the biggest square available
self.width = self.height = min(availWidth, availHeight)
return self.width, self.height
def draw(self):
# here standard and documented QrCodeWidget usage on
# Flowable canva
qr_code = qr.QrCodeWidget(self.qr_value)
bounds = qr_code.getBounds()
qr_width = bounds[2] - bounds[0]
qr_height = bounds[3] - bounds[1]
w = float(self.width)
d = Drawing(w, w, transform=[w/qr_width, 0, 0, w/qr_height, 0, 0])
d.add(qr_code)
renderPDF.draw(d, self.canv, 0, 0)