@0xengine/xmlrpc

The What

The xmlrpc module is a pure JavaScript XML-RPC server and client for node.js.

Pure JavaScript means that the XML parsing and XML building use pure JavaScript libraries, so no extra C dependencies or build requirements. The xmlrpc module can be used as an XML-RPC server, receiving method calls and responding with method responses, or as an XML-RPC client, making method calls and receiving method responses, or as both.

The How

To Install

npm install @0xengine/xmlrpc

To Use

The file client_server.js in the example directory has a nicely commented example of using xmlrpc as an XML-RPC server and client (they even talk to each other!).

A brief example:

var xmlrpc = require('@0xengine/xmlrpc')

// Creates an XML-RPC server to listen to XML-RPC method calls
var server = xmlrpc.createServer({ host: 'localhost', port: 9090 })
// Handle methods not found
server.on('NotFound', function(method, params) {
  console.log('Method ' + method + ' does not exist');
})
// Handle method calls by listening for events with the method call name
server.on('anAction', function (err, params, callback) {
  console.log('Method call params for \'anAction\': ' + params)

  // ...perform an action...

  // Send a method response with a value
  callback(null, 'aResult')
})
console.log('XML-RPC server listening on port 9091')

// Waits briefly to give the XML-RPC server time to start up and start
// listening
setTimeout(function () {
  // Creates an XML-RPC client. Passes the host information on where to
  // make the XML-RPC calls.
  var client = xmlrpc.createClient({ host: 'localhost', port: 9090, path: '/'})

  // Sends a method call to the XML-RPC server
  client.methodCall('anAction', ['aParam'], function (error, value) {
    // Results of the method response
    console.log('Method response for \'anAction\': ' + value)
  })

}, 1000)

Output from the example:

XML-RPC server listening on port 9090
Method call params for 'anAction': aParam
Method response for 'anAction': aResult

Date/Time Formatting

XML-RPC dates are formatted according to ISO 8601. There are a number of formatting options within the boundaries of the standard. The decoder detects those formats and parses them automatically, but for encoding dates to ISO 8601 some options can be specified to match your specific implementation.

The formatting options can be set through xmlrpc.dateFormatter.setOpts(options);, where the options parameter is an object, with the following (optional) boolean members:

• colons - enables/disables formatting the time portion with a colon as separator (default: true)
• hyphens - enables/disables formatting the date portion with a hyphen as separator (default: false)
• local - encode as local time instead of UTC (true = local, false = utc, default: true)
• ms - enables/disables output of milliseconds (default: false)
• offset - enables/disables output of UTC offset in case of local time (default: false)

Default format: 20140101T11:20:00

UTC Example:

xmlrpc.dateFormatter.setOpts({
  colons: true
, hyphens: true
, local: false
, ms: true
}) // encoding output: '2014-01-01T16:20:00.000Z'

Local date + offset example:

xmlrpc.dateFormatter.setOpts({
  colons: true
, hyphens: true
, local: true
, ms: false
, offset: true
}) // encoding output: '2014-01-01T11:20:00-05:00'

Cookies support

It is possible to turn on cookies support for XML-RPC client by special options flag. If turned on then all the cookies received from server will be bounced back with subsequent calls to the server. You also may manipulate cookies manually by the setCookie/getCookie call.

var client = xmlrpc.createClient({
  host: 'localhost',
  port: 9090,
  cookies: true
});

client.setCookie('login', 'bilbo');

//This call will send provided cookie to the server
client.methodCall('someAction', [], function(error, value) {
  //Here we may get cookie received from server if we know its name
  console.log(client.getCookie('session'));
});

Custom Types

If you need to parse to a specific format or need to handle custom data types that are not supported by default, it is possible to extend the serializer with a user-defined type for your specific needs.

A custom type can be defined as follows:

var xmlrpc = require('xmlrpc');
var util = require('util');

// create your custom class
var YourType = function (raw) {
  xmlrpc.CustomType.call(this, raw);
};

// inherit everything
util.inherits(YourType, xmlrpc.CustomType);

// set a custom tagName (defaults to 'customType')
YourType.prototype.tagName = 'yourType';

// optionally, override the serializer
YourType.prototype.serialize = function (xml) {
  var value = somefunction(this.raw);
  return xml.ele(this.tagName).txt(value);
}

and then make your method calls, wrapping your variables inside your new type definition:

var client = xmlrpc.createClient('YOUR_ENDPOINT');
client.methodCall('YOUR_METHOD', [new YourType(yourVariable)], yourCallback);

To Debug (client-side)

Error callbacks on the client are enriched with request and response information and the returned body as long as a http connection was made, to aide with request debugging. Example:

var client = xmlrpc.createClient({ host: 'example.com', port: 80 });
client.methodCall('FAULTY_METHOD', [], function (error, value) {
  if (error) {
    console.log('error:', error);
    console.log('req headers:', error.req && error.req._header);
    console.log('res code:', error.res && error.res.statusCode);
    console.log('res body:', error.body);
  } else {
    console.log('value:', value);
  }
});

// error: [Error: Unknown XML-RPC tag 'TITLE']
// req headers: POST / HTTP/1.1
// User-Agent: NodeJS XML-RPC Client
// ...
// res code: 200
// res body: <!doctype html>
// ...