How To Detect Window Print Finish

Printing documents from a web browser is something many of us do regularly. However, it can sometimes be tricky to know exactly when the print job has finished, especially when dealing with more complex prints or automating tasks. In this article, we will explore how you can detect when a document has finished printing from a browser window, specifically focusing on the 'window.print()' function commonly used for printing.

One way to detect when a print job has finished is by listening for events triggered during the printing process. When you initiate a print job using 'window.print()', the browser fires a series of events that can be used to track the progress of the print job. One such event is the 'afterprint' event, which is triggered by the browser when the print dialog is closed. You can listen for this event using JavaScript to know when the printing process has completed.

To implement this, you can add an event listener for the 'afterprint' event on the 'window' object. Below is an example code snippet showing how you can detect when a print job finishes:

window.addEventListener('afterprint', function() {
    console.log('Print job completed successfully');
});

By adding this event listener to your code, you can receive a notification in the console or trigger a custom function when the print job finishes. This can be particularly useful if you need to perform additional actions or display a message once the printing process is complete.

It's important to note that not all browsers support the 'afterprint' event, so you may need to consider alternative methods for detecting print job completion in those cases. Another approach is to use a timeout mechanism to check for changes in the browser's print status after initiating the print job. While this method may not be as precise as listening for events, it can still be effective in many situations.

Here's a simplified example of how you can use a timeout to detect when a print job finishes:

var isPrinting = false;

// Initiate the print job
window.print();

// Check print status every second
var checkPrintStatus = setInterval(function() {
    if (!document.webkitHidden && !isPrinting) {
        console.log('Print job completed successfully');
        isPrinting = true;
        clearInterval(checkPrintStatus);
    }
}, 1000);

In this code snippet, we continuously check the visibility status of the document to determine when the print job has completed. Once the document becomes visible again after printing, we assume that the print job is done and log a message to the console.

Overall, detecting when a window print job finishes can be achieved by leveraging browser events or using a timeout mechanism to monitor the print status. By incorporating these techniques into your web applications, you can enhance the user experience and provide more insights into the printing process.