Saving XML File using Javascript

Question

i have function readXML that will read the value from given xml file and it will replace specific node value , after replacing the specific value, same thing has to be reflected the raw file( I mean books.xml file), after doing the modification how to save the content in xml file.

Ex: Code for replacing node.

function readXML() {

        xmlDoc = loadXMLDoc("books.xml");

        x = xmlDoc.documentElement;

        //create a book element, title element and a text node
        newNode = xmlDoc.createElement("book");
        newTitle = xmlDoc.createElement("title");
        newText = xmlDoc.createTextNode("A Notebook");

        //add the text node to the title node,
        newTitle.appendChild(newText);
        //add the title node to the book node
        newNode.appendChild(newTitle);

        y = xmlDoc.getElementsByTagName("book")[1]
        //replace the first book node with the new node
        x.replaceChild(newNode, y);

        z = xmlDoc.getElementsByTagName("title");
        for (i = 0; i < z.length; i++) {
            alert(z[i].childNodes[0].nodeValue);

        }

       //Here i have to save the xmlDoc in my local system.

    }

    function loadXMLDoc(dname) {
        if (window.XMLHttpRequest) {
            xhttp = new XMLHttpRequest();
        }
        else {
            xhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xhttp.open("GET", dname, false);
        xhttp.send();
        return xhttp.responseXML;
    }

I am new to XML.

Solution

You can download it using FileSaver

var blob = new Blob([xmpString], {type: "text/xml"});

saveAs(blob, "test.xmp");