How to Serialize a DOM to XML Text in a Cross-Browser Way Using JavaScript

When working with XML data in web applications, you may encounter situations where you need to serialize a DOM object to XML text. This task can become complex, especially when considering cross-browser compatibility. If you’re using an XML object that you load using XMLHTTPRequest, and you want to save it as a string after modifying it with jQuery, you might ask: How do I serialize a DOM to XML text in a way that works across different browsers?

The Challenge of Cross-Browser Serialization

With various browsers implementing different APIs and features, serializing XML can result in inconsistent experiences. Modern browsers like Firefox and Chrome provide a straightforward way to serialize XML through the XMLSerializer interface. However, older browsers, like Internet Explorer, handle XML serialization differently, which can lead to compatibility issues when trying to develop applications that function seamlessly across all platforms.

Solution Overview

To serialize a DOM node to XML text across different browsers, you can use a combination of modern and legacy methods. Below is a step-by-step guide to achieving this with a simple function:

Step 1: Create the Function

The first step is to create a function that attempts to serialize the XML using the XMLSerializer method for modern browsers, while gracefully falling back to an alternative method for older browsers like IE.

Here’s a concise example of such a function:

function xml2Str(xmlNode) {
    try {
        // Modern browsers (Gecko- and Webkit-based: Firefox, Chrome, Opera).
        return (new XMLSerializer()).serializeToString(xmlNode);
    } catch (e) {
        try {
            // Internet Explorer.
            return xmlNode.xml;
        } catch (e) {  
            // Handle unsupported cases.
            alert('XmlSerializer not supported in this browser');
        }
    }
    return false; // Return false if serialization fails
}

Step 2: How the Function Works

• Try Block 1: The function first attempts to serialize the XMLNode using XMLSerializer, which is universally supported in modern browsers. This is the preferred method and returns the serialized XML as a string.

• Try Block 2: If the first attempt fails (in IE), it catches an error and tries to access the xml property of the node, which is a method supported in Internet Explorer. This will retrieve the XML text.

• Catch Block: If both methods fail, the function alerts the user that serialization isn’t supported in their browser. This is important for debugging and user feedback.

Conclusion

By employing this simple two-pronged approach, you can ensure that your XML serialization works across different browsers without introducing unnecessary complexities. While the XMLSerializer method is preferred for modern applications, this function provides a robust solution that accommodates older browsers, ensuring compatibility and functionality.

By understanding and utilizing this serialization technique, you can confidently manipulate and store XML data in your web applications, regardless of the user’s browser.