What is xml-js?
The xml-js npm package is a utility that provides methods to convert between XML and JSON format. It can also convert between XML and JavaScript objects. This package is useful when working with XML data in JavaScript environments where JSON is more easily manipulated.
What are xml-js's main functionalities?
XML to JSON Conversion
Converts an XML string to a JSON string. The options object can be used to customize the output.
const convert = require('xml-js');
const xml = '<note><to>User</to><from>Library</from><heading>Reminder</heading><body>Don't forget me this weekend!</body></note>';
const options = {compact: true, ignoreComment: true, spaces: 4};
const result = convert.xml2json(xml, options);
console.log(result);
JSON to XML Conversion
Converts a JSON string to an XML string. The options object can be used to customize the output.
const convert = require('xml-js');
const json = '{"note":{"to":"User","from":"Library","heading":"Reminder","body":"Don't forget me this weekend!"}}';
const options = {compact: true, ignoreComment: true, spaces: 4};
const result = convert.json2xml(json, options);
console.log(result);
XML to JavaScript Object
Converts an XML string to a JavaScript object. The options object can be used to customize the output.
const convert = require('xml-js');
const xml = '<note><to>User</to><from>Library</from><heading>Reminder</heading><body>Don't forget me this weekend!</body></note>';
const result = convert.xml2js(xml, {compact: true, spaces: 4});
console.log(result);
JavaScript Object to XML
Converts a JavaScript object to an XML string. The options object can be used to customize the output.
const convert = require('xml-js');
const jsObject = {
note: {
to: 'User',
from: 'Library',
heading: 'Reminder',
body: 'Don't forget me this weekend!'
}
};
const options = {compact: true, spaces: 4};
const result = convert.js2xml(jsObject, options);
console.log(result);
Other packages similar to xml-js
fast-xml-parser
A very fast XML parser and validator with a similar feature set to xml-js. It can parse XML to a JavaScript object/JSON and vice versa. It is known for its performance and, unlike xml-js, includes XML validation.
xml2js
Another popular XML to JavaScript converter that provides a similar conversion functionality as xml-js. It includes options to customize the parser behavior and, like xml-js, it does not validate the XML.
xmlbuilder
This package allows for building XML documents from JavaScript objects, focusing on the creation of XML content. It is more specialized in generating XML and does not provide parsing from XML to JavaScript objects.
Convert XML text to Javascript object (and vice versa) or to JSON text (and vice versa):
Motivation
There are many XML to JavaScript/JSON converters out there, but could not satisfy the following requirements:
- Maintain order of sub-nodes in xml:
I wanted
<a/><b/><a/>
to give output as {"elements":[{"type":"element","name":"a"},{"type":"element","name":"b"},{"type":"element","name":"a"}]}
instead of {a:{},b:{}}
. - Fully XML Compliant
- Portable (this is default behavior: only Javascript code, slower execution)
- Fast (if required; will compile on VC++)
- Support streaming
- Support command line
Usage
Installation
npm install xml-js
Quick start
var convert = require('xml-js');
var xml =
'<?xml version="1.0" encoding="utf-8"?>' +
'<note importance="high" logged="true">' +
' <title>Happy</title>' +
' <todo>Work</todo>' +
' <todo>Play</todo>' +
'</note>';
var result1 = convert.xml2json(xml, {compact: true, spaces: 4});
var result2 = convert.xml2json(xml, {compact: false, spaces: 4});
console.log(result1, '\n', result2);
Examples
API Reference
1. Convert JS object / JSON → XML
To convert JavaScript object to XML text, use js2xml()
. To convert JSON text to XML text, use json2xml()
.
var convert = require('xml-js');
var json = require('fs').readFileSync('test.json');
var options = {ignoreText: true, spaces: 4};
var result = convert.json2xml(json, options);
console.log(result);
2. Options for Converting JS object / JSON → XML
The below options are applicable for both js2xml()
and json2xml()
functions.
Option | Default | Description |
---|
ignoreDeclaration | false | Whether to ignore writing declaration directives of xml. For example, <?xml?> will be ignored. |
ignoreAttributes | false | Whether to ignore writing texts of the elements. For example, x="1" in <a x="1"></a> will be ignored |
ignoreText | false | Whether to ignore writing texts of the elements. For example, hi text in <a>hi</a> will be ignored. |
ignoreComment | false | Whether to ignore writing comments of the elements. That is, no <!-- --> will be generated. |
ignoreCdata | false | Whether to ignore writing CData of the elements. That is, no <![CDATA[ ]]> will be generated. |
spaces | 0 | Number of spaces to be used for indenting XML output. |
fromCompact | false | whether the source object is in compact form. |
fullTagEmptyElement | false | Whether to produce element without sub-elements as full tag pairs <a></a> rather than self closing tag </a> . |
3. Convert XML → JS object / JSON
To convert XML text to JavaScript object, use xml2js()
. To convert XML text to JSON text, use xml2json()
.
var convert = require('xml-js');
var xml = require('fs').readFileSync('test.xml');
var options = {ignoreText: true, emptyChildren: true};
var result = convert.xml2js(xml, options);
console.log(result);
4. Options for Converting XML → JS object / JSON
The below options are applicable for both xml2js()
and xml2json()
functions.
Option | Default | Description |
---|
ignoreDeclaration | false | Whether to ignore writing declaration property. That is, no declaration property will be generated. |
ignoreAttributes | false | Whether to ignore writing attributes of elements.That is, no attributes property will be generated. |
ignoreText | false | Whether to ignore writing texts of the elements. That is, no text property will be generated. |
ignoreComment | false | Whether to ignore writing comments of the elements. That is, no comment will be generated. |
ignoreCdata | false | Whether to ignore writing CData of the elements. That is, no cdata property will be generated. |
compact | false | Whether to produce detailed object or compact object. |
emptyChildren | false | Whether to always generate elements property even when there are no actual sub elements. |
addParent | false | Whether to add parent property in each element object that points to parent object. |
trim | false | Whether to trim white space characters that may exist before and after the text. |
nativeType | false | whether to attempt converting text of numerals or of boolean values to native type. For example, "123" will be 123 and "true" will be true |
sanitize | false | Whether to replace & < > " ' with & < > " ' respectively in the resultant text. |
The below option is applicable only for xml2json()
function.
Option | Default | Description |
---|
spaces | 0 | Number of spaces to be used for indenting JSON output. |
5. Options for Changing Key Names
To change default key names in the output object or the default key names assumed in the input JavaScript object / JSON, use the following options:
Option | Default | Description |
---|
declarationKey | "declaration" or "_declaration" | Name of the property key which will be used for the declaration. For example, if declarationKey: '$declaration' then output of <?xml?> will be {"$declaration":{}} (in compact form) |
attributesKey | "attributes" or "_attributes" | Name of the property key which will be used for the attributes. For example, if attributesKey: '$attributes' then output of <a x="hello"/> will be {"a":{$attributes:{"x":"hello"}}} (in compact form) |
textKey | "text" or "_text" | Name of the property key which will be used for the text. For example, if textKey: '$text' then output of <a>hi</a> will be {"a":{"$text":"Hi"}} (in compact form) |
commentKey | "comment" or "_comment" | Name of the property key which will be used for the comment. For example, if commentKey: '$comment' then output of <!--note--> will be {"$comment":"note"} (in compact form) |
cdataKey | "cdat" or "_cdata" | Name of the property key which will be used for the cdata. For example, if cdataKey: '$cdata' then output of <![CDATA[1 is < 2]]> will be {"$cdata":"1 is < 2"} (in compact form) |
parentKey | "parent" or "_parent" | Name of the property key which will be used for the parent. For example, if parentKey: '$parent' then output of <a></b></a> will be {"a":{"b":{$parent:_points_to_a}}} (in compact form) |
typeKey | "type" | Name of the property key which will be used for the type. For example, if typeKey: '$type' then output of <a></a> will be {"elements":[{"$type":"element","name":"a","attributes":{}}]} (in non-compact form) |
nameKey | "name" | Name of the property key which will be used for the name. For example, if nameKey: '$name' then output of <a></a> will be {"elements":[{"type":"element","$name":"a","attributes":{}}]} (in non-compact form) |
elementsKey | "elements" | Name of the property key which will be used for the elements. For example, if elementsKey: '$elements' then output of <a></a> will be {"$elements":[{"type":"element","name":"a","attributes":{}}]} (in non-compact form) |
Tests
To perform tests on this project:
cd node_modules/xml-js
npm install
npm test
For live testing, use npm start
instead of npm test
.
Contributions
Reporting
Use this link to report an issue or bug. Please include a sample code or Jasmine test spec where the code is failing.
Contributing
If you want to add a feature or fix a bug, please fork the repository and make the changes in your fork. Add tests to ensure your code is working properly, then submit a pull request.
License
MIT