ECMAScript for XML

ECMAScript for XML (E4X) was an extension to ECMAScript (which includes ActionScript, JavaScript, and JScript) to add native support for XML.^[1] The goal was to provide a simpler alternative to the DOM interface for accessing XML documents. E4X added XML as a primitive data structure to allow for faster access^{[clarification needed]} and better support within the language.

E4X was standardized by Ecma International in the ECMA-357 standard. The first edition was published in June 2004 and the second edition in December 2005. However, the E4X standard was deprecated by the Mozilla Foundation in 2014,^[2] and it was withdrawn by ISO/IEC in 2021.^[1]

The first implementation of E4X was designed by Terry Lucas and John Schneider and appeared in BEA's Weblogic Workshop 7.0, released in February 2002.^{[citation needed]} BEA's implementation was based on Rhino and released before the ECMAScript E4X spec was completed in June 2004.^{[citation needed]}

Browser support

E4X is supported by Mozilla's Rhino, as well as by Tamarin, the JavaScript engine used in the Flash virtual machine.^{[citation needed]} However, it is not supported by other common engines like Nitro (Safari), V8 (Google Chrome), Carakan (Opera), and Chakra (Internet Explorer).^[3]

E4X was supported by SpiderMonkey (used in Firefox and Thunderbird). However, E4X was deprecated in Firefox 10^[4] and eventually removed in Firefox 21.^{[5][clarification needed]}

E4X was supported by the OpenOffice.org software suite.^{[citation needed]}

Example

var sales = <sales vendor="John">
    <item type="peas" price="4" quantity="6"/>
    <item type="carrot" price="3" quantity="10"/>
    <item type="chips" price="5" quantity="3"/>
  </sales>;

alert( sales.item.(@type == "carrot").@quantity );
alert( sales.@vendor );
for each( var price in sales..@price ) {
  alert( price );
}
delete sales.item[0];
sales.item += <item type="oranges" price="4"/>;
sales.item.(@type == "oranges").@quantity = 4;

See also

• JSX – an XML based markup specifically for DOM manipulation