How to detect when a Printer is added or created, updated, deleted or removed from Javascript

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Product JSPrintManager Published 06/26/2020 Updated 11/05/2026 Author Neodynamic

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Overview

In this walkthrough, you'll learn how to detect when a new printer is added/created, when a printer is removed/deleted, and when any changes or modifications (updates) are done on any printers available at the client machine.

Try reproducing the following sample code locally...

Step-by-step

• JSPrintManager Client App

  Be sure you install in your dev machine JSPrintManager (JSPM) (Available for Windows, Linux, Raspberry Pi & Mac)
  
  
  IMPORTANT: This small app must be installed on each client that will use your website!
  Since Chrome 142, browsers ask the user to allow Local Network Access the first time your website connects to the JSPrintManager App.

• HTML & Script References

  • Download JSPrintManager.js
  • Copy all of these *.js files to the same folder where the next index.html page sample will be located in.
  • By using your favorite Web Development IDE or Text Editor, create a new HTML file naming it index.html
    Copy/paste the following code inside that html file:
    
    

    
    <!DOCTYPE html>
    <html>
    <head>
        <title>JSPrintManager</title>
        <meta charset="utf-8" />
    </head>
    <body>
        <div style="text-align:center">
            <h1>Printers Watcher from Javascript</h1>
            <p>Add, remove or change a printer in this Windows machine and see the events below.</p>
            <hr />
            <textarea id="txtPrintersTrace" rows="15" cols="120" readonly></textarea>
        </div>
    
        <!-- JSPrintManager.js (download it or install it with: npm install jsprintmanager) -->
        <script src="JSPrintManager.js"></script>
        <script>
            var printerCreatedEventID = null;
            var printerUpdatedEventID = null;
            var printerDeletedEventID = null;
    
            // Start the connection with the JSPrintManager Client App
            JSPM.JSPrintManager.auto_reconnect = true;
            JSPM.JSPrintManager.start();
            JSPM.JSPrintManager.WS.onStatusChanged = function () {
                if (jspmWSStatus()) {
                    // subscribe to the printers events (Windows clients only)
                    if (!printerCreatedEventID) {
                        printerCreatedEventID = JSPM.JSPrintManager.onPrinterCreated(
                            function (data) { log("PRINTER CREATED! >>> " + JSON.stringify(data)); },
                            function (err) { console.error(err); });
                        printerUpdatedEventID = JSPM.JSPrintManager.onPrinterUpdated(
                            function (data) { log("PRINTER UPDATED! >>> " + JSON.stringify(data)); },
                            function (err) { console.error(err); });
                        printerDeletedEventID = JSPM.JSPrintManager.onPrinterDeleted(
                            function (data) { log("PRINTER DELETED! >>> " + JSON.stringify(data)); },
                            function (err) { console.error(err); });
                    }
                }
            };
    
            // Stop watching the printers when leaving the page
            window.addEventListener('beforeunload', function () {
                if (printerCreatedEventID) JSPM.JSPrintManager.unsubscribePrinterEvent(printerCreatedEventID);
                if (printerUpdatedEventID) JSPM.JSPrintManager.unsubscribePrinterEvent(printerUpdatedEventID);
                if (printerDeletedEventID) JSPM.JSPrintManager.unsubscribePrinterEvent(printerDeletedEventID);
            });
    
            // Write a line in the printers trace
            function log(text) {
                console.info(text);
                document.getElementById('txtPrintersTrace').value += text + "\r\n";
            }
    
            // Check the connection status with the JSPrintManager Client App
            function jspmWSStatus() {
                var status = JSPM.JSPrintManager.websocket_status;
                if (status == JSPM.WSStatus.Open) {
                    return true;
                } else if (status == JSPM.WSStatus.WaitingForUserResponse) {
                    console.info('Waiting for the user to allow this website (JSPrintManager dialog or browser Local Network Access prompt)...');
                } else if (status == JSPM.WSStatus.Blocked) {
                    alert('JSPrintManager has blocked this website!');
                } else if (status == JSPM.WSStatus.NotInstalled || status == JSPM.WSStatus.Closed) {
                    alert('JSPrintManager Client App is not installed or not running! Download it from https://neodynamic.com/downloads/jspm');
                } else if (status == JSPM.WSStatus.CertificateError) {
                    alert('A TLS/SSL certificate error prevented the connection with JSPrintManager Client App.');
                } else if (status == JSPM.WSStatus.ConnectionError) {
                    alert('A network error (e.g. a firewall) prevented the connection with JSPrintManager Client App.');
                }
                return false;
            }
        </script>
    </body>
    </html>
    

  
  
• That's it! Run your website and test it.

Try JSPrintManager Online Demo!