barcode model property

barcode.py

from base64 import b64encode
from reportlab.lib import units
from reportlab.graphics import renderPM
from reportlab.graphics.barcode import createBarcodeDrawing
from reportlab.graphics.shapes import Drawing

class barcode:
	def get_barcode(self, value, width, barWidth = 0.05 * units.inch, fontSize = 30, humanReadable = True):

		barcode = createBarcodeDrawing('Code128', value = value, barWidth = barWidth, fontSize = fontSize, humanReadable = humanReadable)

		drawing_width = width
		barcode_scale = drawing_width / barcode.width
		drawing_height = barcode.height * barcode_scale

		drawing = Drawing(drawing_width, drawing_height)
		drawing.scale(barcode_scale, barcode_scale)
		drawing.add(barcode, name='barcode')

		return b64encode(renderPM.drawToString(drawing, fmt = 'PNG'))

models.py

@property
def barcode(self):
	from barcode import barcode as barcode
	data = barcode().get_barcode(value = str(self.id), width = 600)

	return u'data:image/png;base64,%s' % (data)