Simple XML to JavaScript object converter.
npm install browser-xml2jsbrowser-xml2js
===========
This is a fork of node-xml2js
It is meant to be used in a browser environment, whereas the upstream is meant to
be used in NodeJS environment.
It ships with browser stream and
timers.
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!
Description
===========
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.
Installation
============
Simplest way to install xml2js is to use npm, just npm
which will download xml2js and all dependencies.
install xml2js
xml2js is also available via Bower, just bower install
which will download xml2js and all dependencies.
xml2js
Usage
=====
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:
``javascript
`
var parseString = require('xml2js').parseString;
var xml = "
parseString(xml, function (err, result) {
console.dir(result);
});
xml2js
Can't get easier than this, right? This works starting with 0.2.3.
`
With CoffeeScript it looks like this:
coffeescript
`
{parseString} = require 'xml2js'
xml = "
parseString xml, (err, result) ->
console.dir result
xml2js
If you need some special options, fear not, supports a number of
`
options (see below), you can specify these as second argument:
javascript
`
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:
javascript
`
var fs = require('fs'),
xml2js = require('xml2js');
var parser = new xml2js.Parser();
fs.readFile(__dirname + '/foo.xml', function(err, data) {
parser.parseString(data, function (err, result) {
console.dir(result);
console.log('Done');
});
});
xml2js
Look ma, no event listeners!
You can also use from
`
CoffeeScript, further reducing
the clutter:
coffeescript
`
fs = require 'fs',
xml2js = require 'xml2js'
parser = new xml2js.Parser()
fs.readFile __dirname + '/foo.xml', (err, data) ->
parser.parseString data, (err, result) ->
console.dir result
console.log 'Done.'
new
But what happens if you forget the keyword to create a new Parser? In
xml2js
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 will helpfully add it for you, no bad surprises and
xml2js.Parser
inexplicable bugs!
Parsing multiple files
----------------------
If you want to parse multiple files, you have multiple possibilities:
* You can create one per file. That's the recommended one
reset()
and is promised to always just work.
* You can call on your parser object.
result
* 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 object in a call to JSON.stringify like this
JSON.stringify(result). You get a string containing the JSON representation
console.dir
of the parsed object that you can feed to JSON-hungry consumers.
Displaying results
------------------
You might wonder why, using or console.log the output at some
[Object]
level is only . Don't worry, this is not because xml2js got lazy.
util.inspect
That's because Node uses to convert the object into strings and
depth=2
that function stops after which is a bit low for most XML.
console.log(util.inspect(result, false,
To display the whole deal, you can use
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,
maxLength
you just need to increase the limit by creating a custom inspector
var inspect = require('eyes').inspector({maxLength: false}) and then you can
inspect(result)
easily .
`
XML builder usage
-----------------
Since 0.4.0, objects can be also be used to build XML:
javascript
`
var xml2js = require('xml2js');
var obj = {name: "Super", Surname: "Man", age: 23};
var builder = new xml2js.Builder();
var xml = builder.buildObject(obj);
attrkey
At the moment, a one to one bi-directional conversion is guaranteed only for
default configuration, except for , charkey and explicitArray options
cdata
you can redefine to your taste. Writing CDATA is supported via setting the
true
option to .
`
To specify attributes:
javascript
`
var xml2js = require('xml2js');
var obj = {root: {$: {id: "my id"}, _: "my inner text"}};
var builder = new xml2js.Builder();
var xml = builder.buildObject(obj);
`
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):
javascript
`
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
});
tagNameProcessors
The and attrNameProcessors options
Array
accept an of functions with the following signature:
`
javascript
name
function (name){
//do something with
`
return name
}
attrValueProcessors
The and valueProcessors options
Array
accept an of functions with the following signature:
`
javascript
name
function (value, name) {
// will be the node name or attribute name
value
//do something with , (optionally) dependent on the node/attr name
`
return value
}
lib/processors.js
Some processors are provided out-of-the-box and can be found in :
normalize
- : transforms the name to lowercase.
options.normalize
(Automatically used when is set to true)
firstCharLowerCase
- : transforms the first character to lower case.
stripPrefix
E.g. 'MyTagName' becomes 'myTagName'
- : strips the xml namespace prefix. E.g will become 'Bar'.
xmlns
(N.B.: the prefix is NOT stripped.)
parseNumbers
- : parses integer-like strings as integers and float-like strings as floats
parseBooleans
E.g. "0" becomes 0 and "15.56" becomes 15.56
- : parses boolean-like strings to booleans
E.g. "true" becomes true and "False" becomes false
Options
=======
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: $): Prefix that is used to access the attributes.
@
Version 0.1 default was .
charkey
* (default: _): Prefix that is used to access the character
#
content. Version 0.1 default was .
explicitCharkey
* (default: false)
trim
* (default: false): Trim the whitespace at the beginning and end of
normalizeTags
text nodes.
* (default: false): Normalize all tag names to lowercase.
normalize
* (default: false): Trim whitespaces inside text nodes.
explicitRoot
* (default: true): Set this if you want to get the root
emptyTag
node in the resulting object.
* (default: ''): what will the value of empty nodes be.
explicitArray
* (default: true): Always put child nodes in an array if
ignoreAttrs
true; otherwise an array is created only if there is more than one.
* (default: false): Ignore all XML attributes and only create
mergeAttrs
text nodes.
* (default: false): Merge attributes and child elements as
ignoreAttrs
properties of the parent, instead of keying attributes off a child
attribute object. This option is ignored if is false.
validator
* (default null): You can specify a callable that validates
xmlns
the resulting structure somehow, however you want. See unit tests
for an example.
* (default false): Give each element a field usually called '$ns'
explicitChildren
(the first character is the same as attrkey) that contains its local name
and namespace URI.
* (default false): Put child elements to separate
mergeAttrs = true
property. Doesn't work with . If element has no children
childkey
then "children" won't be created. Added in 0.2.5.
* (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
true
ordered array. When this is , every node will also get a #name field
charsAsChildren
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
0.4.9.
* (default false): Determines whether chars should be
explicitChildren
considered children if is on. Added in 0.2.5.
includeWhiteChars
* (default false): Determines whether whitespace-only
async
text nodes should be included. Added in 0.4.17.
(default false): Should the callbacks be async? This might* be
xml2js
an incompatible change if your code depends on sync execution of callbacks.
Future versions of might change this default, so the recommendation
strict
is to not depend on sync execution anyway. Added in 0.2.6.
* (default true): Set sax-js to strict or non-strict parsing mode.
true
Defaults to which is highly recommended, since parsing HTML which
attrNameProcessors
is not well-formed XML might yield just about anything. Added in 0.2.7.
* (default: null): Allows the addition of attribute
Array
name processing functions. Accepts an of functions with following
`
signature:
javascript
name
function (name){
//do something with
`
return name
}
attrValueProcessors
Added in 0.4.14
* (default: null): Allows the addition of attribute
Array
value processing functions. Accepts an of functions with following
`
signature:
javascript
name
function (name){
//do something with
`
return name
}
tagNameProcessors
Added in 0.4.1
* (default: null): Allows the addition of tag name
Array
processing functions. Accepts an of functions with following
`
signature:
javascript
name
function (name){
//do something with
`
return name
}
valueProcessors
Added in 0.4.1
* (default: null): Allows the addition of element value
Array
processing functions. Accepts an of functions with following
`
signature:
javascript
name
function (name){
//do something with
`
return name
}
Builder
Added in 0.4.6
Options for the class
-------------------------------
These options are specified by new Builder({optionName: value}).
rootName
Possible options are:
* (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' }):
xmldec
Rendering options for xmlbuilder-js.
* pretty: prettify generated XML
* indent: whitespace for indentation (only when pretty)
* newline: newline char (only when pretty)
* (default { 'version': '1.0', 'encoding': 'UTF-8', 'standalone': true }:
xmldec.version
XML declaration attributes.
* 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
cdata
surrogate blocks.
* (default: false): wrap text nodes in instead of
escaping when necessary. Does not add if it is not required.
renderOpts
Added in 0.4.5.
, xmldec,doctype and headless pass through to
`
xmlbuilder-js.
Updating to new version
=======================
Version 0.2 changed the default parsing settings, but version 0.1.14 introduced
the default settings for version 0.2, so these settings can be tried before the
migration.
javascript
`
var xml2js = require('xml2js');
var parser = new xml2js.Parser(xml2js.defaults["0.2"]);
xml2js.defaults["0.1"]
To get the 0.1 defaults in version 0.2 you can just use
in the same place. This provides you with enough time
xml2js
to migrate to the saner way of parsing in 0.2. We try to make the
normalize
migration as simple and gentle as possible, but some breakage cannot be
avoided.
So, what exactly did change and why? In 0.2 we changed some defaults to parse
the XML in a more universal and sane way. So we disabled and trim
xml2js
so does not cut out any text content. You can reenable this at will of
explicitRoot
course. A more important change is that we return the root tag in the resulting
JavaScript structure via the setting, so you need to access the
explicitArray
first element. This is useful for anybody who wants to know what the root node
is and preserves more information. The last major change was to enable
, so everytime it is possible that one might embed more than one
npm test
sub-tag into a tag, xml2js >= 0.2 returns an array even if the array just
includes one element. This is useful when dealing with APIs that return
variable amounts of subtags.
Running tests, development
==========================



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 directly
xml2js
from the project root. This runs zap to discover all the tests and execute
them.
If you like to contribute, keep in mind that is written in
xml2js
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 . It is? Okay, then I'll look at it. Send me a
xml2js`, if so I'll let you know to open an issue instead :)
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
But if you know you really found a bug, feel free to open an issue instead.