Label Printing Mixin
LabelPrintingMixin¶
The LabelPrintingMixin class enables plugins to print labels directly to a connected printer. Custom plugins can be written to support any printer backend.
An example of this is the inventree-brother-plugin which provides native support for the Brother QL and PT series of networked label printers.
Web Integration¶
If label printing plugins are enabled, they are able to be used directly from the InvenTree web interface:
App Integration¶
Label printing plugins also allow direct printing of labels via the mobile app
Implementation¶
Plugins which implement the LabelPrintingMixin mixin class must provide a print_label function:
from dummy_printer import printer_backend
class MyLabelPrinter(LabelPrintingMixin, InvenTreePlugin):
"""
A simple example plugin which provides support for a dummy printer.
A more complex plugin would communicate with an actual printer!
"""
NAME = "MyLabelPrinter"
SLUG = "mylabel"
TITLE = "A dummy printer"
def print_label(self, **kwargs):
"""
Send the label to the printer
kwargs:
pdf_data: An in-memory PDF file of the label
png_file: An in-memory PIL (pillow) Image file of the label
filename: The filename of the printed label (if applicable)
label_instance: The Label model instance
width: width of the label (in mm)
height: height of the label (in mm)
user: The user who printed this label
"""
width = kwargs['width']
height = kwargs['height']
# This dummy printer supports printing of raw image files
printer_backend.print(png_file, w=width, h=height)
Available Data¶
The label data are supplied to the plugin in both PDF and PNG formats. This provides compatibility with a great range of label printers "out of the box". Conversion to other formats, if required, is left as an exercise for the plugin developer.
Other arguments provided to the print_label function are documented in the code sample above.