fast-xml-parser

Validate XML or Parse XML to JS/JSON very fast without C/C++ based libraries and no callback

Changes for V 3.0.0 are in progress which will combine validator and parser and will be able to handle large XML files. So keep watching.

You can use this library online (press try me button above), or as command from CLI, or in your website, or in npm repo.

• This library let you validate the XML data syntactically.
• Or you can transform/covert/parse XML data to JS/JSON object.
• Or you can transform the XML in traversable JS object which can later be converted to JS/JSON object.

How to use

Installation

$npm install fast-xml-parser

or using yarn

$yarn add fast-xml-parser

Usage

var fastXmlParser = require('fast-xml-parser');
var jsonObj = fastXmlParser.parse(xmlData);

// when a tag has attributes
var options = {
    attrPrefix : "@_",
    attrNodeName: false,
    textNodeName : "#text",
    ignoreNonTextNodeAttr : true,
    ignoreTextNodeAttr : true,
    ignoreNameSpace : true,
    ignoreRootElement : false,
    textNodeConversion : true,
    textAttrConversion : false,
    arrayMode : false
};
if(fastXmlParser.validate(xmlData)=== true){//optional
	var jsonObj = fastXmlParser.parse(xmlData,options);
}

//Intermediate obj
var tObj = fastXmlParser.getTraversalObj(xmlData,options);
var jsonObj = fastXmlParser.convertToJson(tObj);

• attrNodeName: (Valid name) Group all the attributes as properties of given name.
• ignoreNonTextNodeAttr : Ignore attributes of non-text node.
• ignoreTextNodeAttr : Ignore attributes for text node
• ignoreNameSpace : Remove namespace string from tag and attribute names.
• ignoreRootElement : Remove root element from parsed JSON.
• textNodeConversion : Parse the value of text node to float or integer.
• textAttrConversion : Parse the value of an attribute to float or integer.
• arrayMode : Put the value(s) of a tag or attribute in an array.

To use from command line

$xml2js [-ns|-a|-c] <filename> [-o outputfile.json]
$cat xmlfile.xml | xml2js [-ns|-a|-c] [-o outputfile.json]

-ns : To include namespaces (bedefault ignored) -a : To ignore attributes -c : To ignore value conversion (i.e. "-3" will not be converted to number -3)

To use it on webpage

1. Download and include parser.js

var isValid = parser.validate(xmlData);
var jsonObj = parser.parse(xmlData);

Or use directly from CDN

Comparision

I decided to created this library when I couldn't find any library which can convert XML data to json without any callback and which is not based on any C/C++ library.

Libraries that I compared

• xml-mapping : fast, result is not satisfactory
• xml2js : fast, result is not satisfactory
• xml2js-expat : couldn't test performance as it gives error on high load. Installation failed on travis and on my local machine using 'yarn'.
• xml2json : based on node-expat which is based on C/C++. Installation failed on travis.
• fast-xml-parser : very very fast.

Why not C/C++ based libraries? Installation of such libraries fails on some OS. You may require to install missing dependency manually.

Benchmark report

Don't forget to check the performance report on comparejs.

validator benchmark: 21000 tps

Your contribution in terms of donation, testing, bug fixes, code development etc. can help me to write fast algorithms.

Give a star, if you really like this project.

Changes from v3 (in progress)

• Can handle big files as well.
• Validator is clubbed with parser
• Meaningful error messages

"err": {
    "code": "InvalidAttr",
    "msg": "Attributes for rootNode have open quote"
}

• Updated options

    var defaultOptions = {
        attrNamePrefix : "@_",                     //prefix for attributes
        attrNodeName: false,                       //Group attributes in separate node
        textNodeName : "#text",                 //Name for property which will have value of the node in case nested nodes are present, or attributes
        ignoreAttributes : true,                     //ignore attributes
        allowBooleanAttributes : false,         //A tag can have attributes without any value
        ignoreNameSpace : false,                 //ignore namespace from the name of a tag and attribute. It also removes xmlns attribute
        parseNodeValue : true,                     //convert the value of node to primitive type. E.g. "2" -> 2
        parseAttributeValue : false,               //convert the value of attribute to primitive type. E.g. "2" -> 2
        trimValues: true,                                //Trim string values of tag and attributes 
    };

• Parse boolean values as well. E.g. "true" to true
• You can set pasrer not to trim whitespaces from attribute or tag /node value.
• Tag / node and attribute value is by default HTML decoded. However CDATA value will not be decoded.
• Tag / node value will not be parsed if CDATA presents.
• Few validation bugs are also fixed

Some of my other NPM pojects

• stubmatic : A stub server to mock behaviour of HTTP(s) / REST / SOAP services. Stubbing redis is on the way.
• compare js : compare the features of JS code, libraries, and NPM repos.
• fast-lorem-ipsum : Generate lorem ipsum words, sentences, paragraph very quickly.

TODO

• P2: validating XML stream data
• P2: validator cli
• P2: fast XML prettyfier