Simple XML to JavaScript object converter.

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React Native XML to JSON Conversion
This is a fork of node-xml2js to support react-native.
Supported Platforms:
  • Android
  • iOS
Ever had the urge to parse XML? And wanted to access the data in some sane, easy way? Don't want to compile a C parser, for whatever reason? Then xml2js is what you're looking for!
Simple XML to JavaScript object converter. It supports bi-directional conversion. Uses sax-js and xmlbuilder-js.
Note: If you're looking for a full DOM parser, you probably want JSDom.
Simplest way to install react-native-xml2js is to use npm, just `npm install react-native-xml2js` which will download react-native-xml2js and all dependencies.
No extensive tutorials required because you are a smart developer! The task of parsing XML should be an easy one, so let's make it so! Here's some examples.

Shoot-and-forget usage

You want to parse XML as simple and easy as possible? It's dangerous to go alone, take this:
var parseString = require('react-native-xml2js').parseString;
var xml = "<root>Hello xml2js!</root>"
parseString(xml, function (err, result) {

Can't get easier than this, right? This works starting with xml2js 0.2.3. With CoffeeScript it looks like this:
{parseString} = require 'xml2js'
xml = "<root>Hello xml2js!</root>"
parseString xml, (err, result) ->
    console.dir result

If you need some special options, fear not, xml2js supports a number of options (see below), you can specify these as second argument:
parseString(xml, {trim: true}, function (err, result) {

Simple as pie usage

That's right, if you have been using xml-simple or a home-grown wrapper, this was added in 0.1.11 just for you:
var fs = require('fs'),
    xml2js = require('react-native-xml2js');

var parser = new xml2js.Parser();
fs.readFile(__dirname + '/foo.xml', function(err, data) {
    parser.parseString(data, function (err, result) {

Look ma, no event listeners!
You can also use xml2js from CoffeeScript, further reducing the clutter:
fs = require 'fs',
xml2js = require 'react-native-xml2js'

parser = new xml2js.Parser()
fs.readFile __dirname + '/foo.xml', (err, data) ->
  parser.parseString data, (err, result) ->
    console.dir result
    console.log 'Done.'

But what happens if you forget the new keyword to create a new Parser? In the middle of a nightly coding session, it might get lost, after all. Worry not, we got you covered! Starting with 0.2.8 you can also leave it out, in which case xml2js will helpfully add it for you, no bad surprises and inexplicable bugs!

Parsing multiple files

If you want to parse multiple files, you have multiple possibilities:
You can create one xml2js.Parser per file. That's the recommended one
and is promised to always *just work*.
You can call reset() on your parser object. You can hope everything goes well anyway. This behaviour is not
guaranteed work always, if ever. Use option #1 if possible. Thanks!

So you wanna some JSON?

Just wrap the result object in a call to JSON.stringify like this JSON.stringify(result). You get a string containing the JSON representation of the parsed object that you can feed to JSON-hungry consumers.

Displaying results

You might wonder why, using console.dir or console.log the output at some level is only [Object]. Don't worry, this is not because xml2js got lazy. That's because Node uses util.inspect to convert the object into strings and that function stops after depth=2 which is a bit low for most XML.
To display the whole deal, you can use `console.log(util.inspect(result, false, null))`, which displays the whole result.
So much for that, but what if you use eyes
for nice colored output and it truncates the output with ? Don't fear, there's also a solution for that, you just need to increase the maxLength limit by creating a custom inspector var inspect = require('eyes').inspector({maxLength: false}) and then you can easily inspect(result).

XML builder usage

Since 0.4.0, objects can be also be used to build XML:
var fs = require('fs'),
    xml2js = require('react-native-xml2js');

var obj = {name: "Super", Surname: "Man", age: 23};

var builder = new xml2js.Builder();
var xml = builder.buildObject(obj);

At the moment, a one to one bi-directional conversion is guaranteed only for default configuration, except for attrkey, charkey and explicitArray options you can redefine to your taste. Writing CDATA is supported via setting the cdata option to true.

Processing attribute, tag names and values

Since 0.4.1 you can optionally provide the parser with attribute name and tag name processors as well as element value processors (Since 0.4.14, you can also optionally provide the parser with attribute value processors):
function nameToUpperCase(name){
    return name.toUpperCase();

//transform all attribute and tag names and values to uppercase
parseString(xml, {
  tagNameProcessors: [nameToUpperCase],
  attrNameProcessors: [nameToUpperCase],
  valueProcessors: [nameToUpperCase],
  attrValueProcessors: [nameToUpperCase]},
  function (err, result) {
    // processed data

The tagNameProcessors, attrNameProcessors, attrValueProcessors and valueProcessors options accept an Array of functions with the following signature:
function (name){
  //do something with `name`
  return name

Some processors are provided out-of-the-box and can be found in lib/processors.js:
  • normalize: transforms the name to lowercase.
(Automatically used when options.normalize is set to true)
  • firstCharLowerCase: transforms the first character to lower case.
E.g. 'MyTagName' becomes 'myTagName'
  • stripPrefix: strips the xml namespace prefix. E.g <foo:Bar/> will become 'Bar'.
(N.B.: the xmlns prefix is NOT stripped.)
  • parseNumbers: parses integer-like strings as integers and float-like strings as floats
E.g. "0" becomes 0 and "15.56" becomes 15.56
  • parseBooleans: parses boolean-like strings to booleans
E.g. "true" becomes true and "False" becomes false
Apart from the default settings, there are a number of options that can be specified for the parser. Options are specified by ``new Parser({optionName: value})``. Possible options are:
attrkey (default: $): Prefix that is used to access the attributes.
Version 0.1 default was `@`.
charkey (default: _): Prefix that is used to access the character
content. Version 0.1 default was `#`.
explicitCharkey (default: false) trim (default: false): Trim the whitespace at the beginning and end of
text nodes.
normalizeTags (default: false): Normalize all tag names to lowercase. normalize (default: false): Trim whitespaces inside text nodes. explicitRoot (default: true): Set this if you want to get the root
node in the resulting object.
emptyTag (default: ''): what will the value of empty nodes be. explicitArray (default: true): Always put child nodes in an array if
true; otherwise an array is created only if there is more than one.
ignoreAttrs (default: false): Ignore all XML attributes and only create
text nodes.
mergeAttrs (default: false): Merge attributes and child elements as
properties of the parent, instead of keying attributes off a child
attribute object. This option is ignored if `ignoreAttrs` is `false`.
validator (default null): You can specify a callable that validates
the resulting structure somehow, however you want. See unit tests
for an example.
xmlns (default false): Give each element a field usually called '$ns'
(the first character is the same as attrkey) that contains its local name
and namespace URI.
explicitChildren (default false): Put child elements to separate
property. Doesn't work with `mergeAttrs = true`. If element has no children
then "children" won't be created. Added in 0.2.5.
childkey (default $$): Prefix that is used to access child elements if
`explicitChildren` is set to `true`. Added in 0.2.5.
preserveChildrenOrder (default false): Modifies the behavior of
`explicitChildren` so that the value of the "children" property becomes an
ordered array. When this is `true`, every node will also get a `#name` field
whose value will correspond to the XML nodeName, so that you may iterate
the "children" array and still be able to determine node names. The named
(and potentially unordered) properties are also retained in this
configuration at the same level as the ordered "children" array. Added in
charsAsChildren (default false): Determines whether chars should be
considered children if `explicitChildren` is on. Added in 0.2.5.
includeWhiteChars (default false): Determines whether whitespace-only
text nodes should be included. Added in 0.4.17.
async (default false): Should the callbacks be async? This might be
an incompatible change if your code depends on sync execution of callbacks.
Future versions of `xml2js` might change this default, so the recommendation
is to not depend on sync execution anyway. Added in 0.2.6.
strict (default true): Set sax-js to strict or non-strict parsing mode.
Defaults to `true` which is *highly* recommended, since parsing HTML which
is not well-formed XML might yield just about anything. Added in 0.2.7.
attrNameProcessors (default: null): Allows the addition of attribute
name processing functions. Accepts an `Array` of functions with following
function (name){
    //do something with `name`
    return name
Added in 0.4.14
attrValueProcessors (default: null): Allows the addition of attribute
value processing functions. Accepts an `Array` of functions with following
function (name){
  //do something with `name`
  return name
Added in 0.4.1
tagNameProcessors (default: null): Allows the addition of tag name
processing functions. Accepts an `Array` of functions with following
function (name){
  //do something with `name`
  return name
Added in 0.4.1
valueProcessors (default: null): Allows the addition of element value
processing functions. Accepts an `Array` of functions with following
function (name){
  //do something with `name`
  return name
Added in 0.4.6

Options for the Builder class

These options are specified by `new Builder({optionName: value})`. Possible options are:
rootName (default root or the root key name): root element name to be used in case
`explicitRoot` is `false` or to override the root element name.
renderOpts (default { 'pretty': true, 'indent': ' ', 'newline': '\n' }):
Rendering options for xmlbuilder-js.
* pretty: prettify generated XML
* indent: whitespace for indentation (only when pretty)
* newline: newline char (only when pretty)
xmldec (default { 'version': '1.0', 'encoding': 'UTF-8', 'standalone': true }:
XML declaration attributes.
* `xmldec.version` A version number string, e.g. 1.0
* `xmldec.encoding` Encoding declaration, e.g. UTF-8
* `xmldec.standalone` standalone document declaration: true or false
doctype (default null): optional DTD. Eg. {'ext': 'hello.dtd'} headless (default: false): omit the XML header. Added in 0.4.3. allowSurrogateChars (default: false): allows using characters from the Unicode
surrogate blocks.
cdata (default: false): wrap text nodes in <![CDATA[ ... ]]> instead of
escaping when necessary. Does not add `<![CDATA[ ... ]]>` if it is not required.
Added in 0.4.5.
renderOpts, xmldec,doctype and headless pass through to xmlbuilder-js
Running tests, development
Build Status Coverage Status Dependency Status
The development requirements are handled by npm, you just need to install them. We also have a number of unit tests, they can be run using npm test directly from the project root. This runs zap to discover all the tests and execute them.
If you like to contribute, keep in mind that xml2js is written in CoffeeScript, so don't develop on the JavaScript files that are checked into the repository for convenience reasons. Also, please write some unit test to check your behaviour and if it is some user-facing thing, add some documentation to this README, so people will know it exists. Thanks in advance!
Getting support
Please, if you have a problem with the library, first make sure you read this README. If you read this far, thanks, you're good. Then, please make sure your problem really is with xml2js. It is? Okay, then I'll look at it. Send me a mail and we can talk. Please don't open issues, as I don't think that is the proper forum for support problems. Some problems might as well really be bugs in xml2js, if so I'll let you know to open an issue instead :)
But if you know you really found a bug, feel free to open an issue instead.