Add comment to xml with nodejs

Question

I am converting an object to an xml with nodejs. I want to add a comment  to the xml. I tried this code but createComment is always undefined.

const xml2js = require('xml2js');
const parser = new xml2js.Parser();
const builder = new xml2js.Builder();

 const parser = new xml2js.Parser();

 parser.parseString(body, (e, myobject) => {
 myobject.test = "test";
const xml = builder.buildObject(myobject);
//NOT WORKING var c = builder.createComment("My personal comment");
//NOT WORKING var c = xml.createComment("My personal comments");
xml.appendChild(c);

I can't find any mention of `createComment` in [the documentation for that module](https://www.npmjs.com/package/xml2js). What is leading you to try using it? — Quentin, Dec 18 '19 at 10:16
Also `buildObject` appears to expect an object to be passed to it, not a string of JSON. — Quentin, Dec 18 '19 at 10:17
Please answer my question. Why do you think `createComment` should exist? — Quentin, Dec 18 '19 at 10:18
That's why documentation exists! Poking blindly at objects is pointless. — Quentin, Dec 18 '19 at 10:26

score 1 · Answer 1 · answered Dec 18 '19 at 10:26

xml2js is a tool for converting between JavaScript objects and XML.

It does not generate a DOM. It has no mechanism for creating comments (which aren't a feature of JavaScript objects).

buildObject returns a string of XML. It doesn't have an appendChild method because it is a string, not a document.

If you want to manipulate the XML with a DOM interface, then you'll need to parse it with an XML library that provides a DOM interface. For example: libxmljs.

const xml2js = require('xml2js');
const builder = new xml2js.Builder();
const libxml = require("libxmljs");
const xml = builder.buildObject({foo: 1, bar: 2});
const xmlDoc = libxml.parseXml(xml);
const foo = xmlDoc.get('//foo');
const comment = new libxml.Comment(xmlDoc, "This is a comment");
foo.addChild(comment);
console.log("" + xmlDoc);

Add comment to xml with nodejs

1 Answers1