In our cloud-application we allow direct printing to a local, network enabled Zebra Printer via a local http-proxy.
For the local HTTP Proxy we use a Raspberry Pi (running Apache + PHP) which takes the Web Request (POST form data), and forwards it onto the printer via Telnet on port 9100.
This does work - the labels print.
The issue, however is that our cloud application is always run via HTTPS (https://app.domain.com/), the Raspberry Pi is HTTP (http://192.168.1.100/) - so every time the user tries to post the form to the Raspberry Pi the browser warns the form is insecure.
I've tried implementing this via Ajax, however an insecure ajax request is blocked outright so it totally stops things working.
I also tried via JSONP, however I found that JSONP does not support POST.
Are there any other method for making this work?