CODEWITHSUNDEEP
xmljsonnode.jsexpressproxy
toddgeist
toddgeist

Reputation: 902

How can I use a node Transform Stream to turn XML into JSON

How do I write a Transform Stream that turns the XML text in a node Req object into JSON so I can pipe it directly to a Node response?

I am building a sort of proxy or wrapper around an XML based web service, to turn the XML into a RESTFul JSON api. The idea is this:

User makes a request to the proxy, the proxy sends a request to the XML service, and gets back a Node Response Stream, which is transformed (by magic stream thing I can't do yet) into JSON and then piped directly back to the response and sent back to the original user.

I can get this to work quite well with Express, or a simple Node Proxy app, with the exception of the XML to JSON part. I understand that I need to build a Transform stream as defined by substack in his stream-handbook and I think I can make use of streamify, but I am uncertain how to proceed.

here is the route I have set up for my express 4 app. I am using superagent to make the second request. This works, but doesn't transform.

'use strict';
var express = require('express'),
    router = express.Router(),
    request = require('superagent'),

router.get('/', function(req, res) {
    request
        .post('http://server.com/some.xml')
       // .pipe(converter(res))
        .pipe(res)

});
module.exports = router;

Upvotes: 1

Views: 704

Answers (1)

mscdex
mscdex

Reputation: 106746

Your best bet is to create a Transform stream that internally uses a module like sax to parse the XML. From there it's up to you how you want to format/output the JSON (especially how you want to deal with XML node attributes and the like).

Also, I'm not familiar with superagent, but you will need to handle the case when the xml request fails so you know to res.send(500); instead.

Upvotes: 1

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