CODEWITHSUNDEEP
javascriptfirefoxprinting
vanguard
vanguard

Reputation: 147

JavaScript windows.print() callback - Determining when a print job completes

Question: Is it possible to add a callback to the windows.print() function? I realize there isn't a native solution, but I was wondering if there is some sort of library that accomplishes this. Note - I have access to the computers if I need to install something.

Background: I have implemented a web POS solution that runs on Firefox (v44-46). For some orders, I need to print 2 receipts on an Epson TM-T88V printer.

Problem: If the second windows.print() method executes while the first receipt is still printing, Firefox prompts "Some printing functionality is not available".

Possible Solution: I can increase the delay between print calls. However, this isn't very robust since some orders can be quite lengthy, whereas others are not. This solution might not work for some cases, and would simply slow down others.

Is there a better way to go about doing this?

Upvotes: 0

Views: 2164

Answers (1)

Paul S.
Paul S.

Reputation: 66384

Seems like you want to listen for the afterprint event

window.addEventListener('afterprint', e => console.log('Ready for next print job'));

Please note that this has low cross-browser support (FireFox 6+, IE)

The MDN page also tells us that something similar can be achieved in webkit based browsers by adding a listener on matchMedia('print'), so you could shim it by writing something like the following for those browsers

window.matchMedia('print').addListener(mql => {
    if (!mql.matches) {
        window.dispatchEvent(new Event('afterprint'));
    }
});

This should work in e.g. Google Chrome

Upvotes: 1

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