[19.0][ADD] pos_printing_qztray: New Module

[miquelalzanillas]

POS Printing QZTray

This module provides an alternative to the Odoo IoT Box for thermal receipt printing in the Point of Sale, using QZ Tray as the print driver.

It extends the existing base_report_to_printer_qztray module — which adds QZ Tray backend support to printing.printer — and brings that functionality into the POS, allowing users to select a printer with backend = qztray directly from the POS configuration.

What this module does?

ESC/POS receipt template using python-escpos library: controllers/main.py contains a full receipt template that generates ESC/POS commands server-side using python-escpos. The template is easily extendable and inheritable from Python without touching any frontend code.

PNG fallback: When no order can be matched (e.g. reprints from the Ticket Screen), the standard HTML receipt is rendered to a raster PNG and converted to ESC/POS format.

Cash drawer support: Sending the cash drawer open command (ESC p) is supported out of the box.

No IoT Box required: The module is designed as a pure-software alternative to the IoT Box, suitable for setups where deploying IoT infrastructure is not desirable.

Configuration

Install and run QZ Tray on the POS machine.

Go to Point of Sale > Configuration > Settings.

Enable QZ Tray Printing and optionally select a printer with backend qztray. If left empty, the system default printer is used.

@angelmoya @cubells @ppyczko @BernatObrador @mpascuall

[cvinh]

Thanks for your module, I have a question :
Can kitchen tickets be printed with this module ? (on a network printer...)?

[miquelalzanillas]

Thanks for your module, I have a question : Can kitchen tickets be printed with this module ? (on a network printer...)?

Hello @cvinh ,

No for the moment but I think it can be implemented with not too much effort.

[BernatObrador]

LGTM

[ppyczko]

LGTM, tested and working in a production environment!

[BhaveshHeliconia]

• I've done all the required configuration like creating qz type printer, setting system parameters for qz certificate and private key, set qz printer in POS session in my local.

• I've tried to test with two types of printers: Virtual printer(Using 'Add printer' from cups web interface) and real printer(Brother DCP-T525W)
  Case-1: Virtual printer(Generic PDF printer): When I tried to print using this, generated PDF is blank.
  Case-2: After clicking print, I get 'printing on...' and 'printing completed...' popups, but doesn't get any actual print from printer.

• In wither case, one thing I noticed is blank print preview in standard print dialog. Proper print preview was there when this module was not installed.

• Could you please check and confirm?

[BernatObrador]

Hi @BhaveshHeliconia,
I think this is expected if the tested printers are not ESC/POS/raw-compatible printers. This module generates ESC/POS/raw data and sends it through QZ Tray, so a generic PDF printer or a standard inkjet/MFP driver will not render it like normal HTML/PDF printing. It should be tested with a real ESC/POS-compatible thermal printer, or with a raw-capable printer/driver/emulator. The “printing completed” message only means QZ/OS accepted the job, not necessarily that the target printer understood the ESC/POS commands.

[BhaveshHeliconia]

@BernatObrador What about blank print preview in standard print dialog? Is this also expected?