pos_self_service_print_zpl

Point Of Sale - Self-Service Print ZPL

This module handles barcode printing from the browser, using ZPL.

Table of contents

• Configuration
  • Printer
  • Reverse proxy with nginx
• Usage
  • Reset a Zebra printer
• Development
  • Generate JavaScript bundle file
• Bug Tracker
• Credits
  • Authors
  • Contributors
  • Maintainers

Configuration

Printer

Add printer to the OS.

Browse to the CUPS configuration page to get the name of the printer that will be used: http://localhost:631/printers. Set this name as the printer name in the POS self-service configuration page.

Center the barcode by trial and error using the label offset and size configuration values of the POS self-service configuration page.

Configure printer to accept several jobs in a row:

lpadmin -p <PRINTERNAME> -o usb-no-reattach-default=true

And restart CUPS to apply the new configuration:

sudo service cups restart

Reverse proxy with nginx

Install nginx:

apt install nginx

Start nginx:

sudo systemctl start nginx.service

Copy this file in:

/etc/nginx/sites-available/cups

upstream cups-reverse-proxy {
    server 127.0.0.1:631 weight=1 fail_timeout=60s;
}

server {
    # server port and name
    listen 8631;
    listen [::]:8631;
    server_name _;

    # ssl log files
    access_log /var/log/nginx/cups-access.log;
    error_log /var/log/nginx/cups-error.log;


    # increase proxy buffer to handle some Odoo web requests
    proxy_buffers 16 64k;
    proxy_buffer_size 128k;

    location / {
        proxy_pass http://cups-reverse-proxy;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Host $server_name;

        add_header 'Access-Control-Allow-Origin' $http_origin always;
        add_header 'Access-Control-Allow-Credentials' * always;
        add_header 'Access-Control-Allow-Methods' * always;
        add_header 'Access-Control-Allow-Headers' * always;
        # required to be able to read Authorization header in frontend
        add_header 'Access-Control-Expose-Headers' * always;

        if ($request_method = 'OPTIONS') {
            # Tell client that this pre-flight info is valid for 20 days
            add_header 'Access-Control-Max-Age' 1728000;
            add_header 'Content-Type' 'text/plain charset=UTF-8';
            add_header 'Content-Length' 0;
            add_header 'Access-Control-Allow-Origin' $http_origin always;
            add_header 'Access-Control-Allow-Credentials' * always;
            add_header 'Access-Control-Allow-Methods' * always;
            add_header 'Access-Control-Allow-Headers' * always;
            # required to be able to read Authorization header in frontend
            add_header 'Access-Control-Expose-Headers' * always;

            return 204;
        }

        # by default, do not forward anything
        proxy_redirect off;
    }
}

Create symbolic link:

sudo ln -s /etc/nginx/sites-available/cups /etc/nginx/sites-enabled/

Check the syntax is ok:

sudo nginx -t
sudo systemctl restart nginx.service

Usage

Reset a Zebra printer

Factory reset video

Development

Generate JavaScript bundle file

This module makes use of the NPM library IPP to send http request to CUPS. The NPM library browserify is used to generate a bundle.js file from the print.js file:

npm -i ipp
npm -g browserify
browserify static/src/js/print.js -o static/src/js/bundle.js

Bug Tracker

Bugs are tracked on GitHub Issues. In case of trouble, please check there if your issue has already been reported. If you spotted it first, help us to smash it by providing a detailed and welcomed feedback.

Do not contact contributors directly about support or help with technical issues.

Credits

Authors

• Coop IT Easy SC

Contributors

• Coop IT Easy SC:

  • Grégoire Leeuwerck <[email protected]>
  • Vincent Van Rossem <[email protected]>

• Le Nid:

  • François Kawala

Maintainers

This module is part of the coopiteasy/addons project on GitHub.

You are welcome to contribute.