W3C Issues New Draft for XMLHttpRequest Specifications

The W3C (World Wide Web Consortium) Web Applications Working Group has published updates to the Working Draft in XMLHttpRequest and XMLHttpRequest Level 2. These specifications govern the way interactive web applications are handled by developers and offer the basic API documentation for programmers wanting to spice up web interactivity with AJAX features.

Updates were made on the same day to the XMLHttpRquest draft and to the XMLHttpRequest Level 2 draft. Development and standard API documentation reside in the care of the W3C Web Applications (WebApps) Working Group, formed of two ex-development groups: WebAPI and WAF Working Group.

This group will function until June 2010, a date to which new specifications regarding AJAX implementations are expected. The XMLHttpRequest Level 2 draft provides a perspective in the potential and possibilities for new AJAX functionality that web applications may contain.

The XMLHttpRequest Object (XHR Object), Level 1 and Level 2, is a dynamic API for client-server data transfer, specifying what is currently implemented and what to extend from its capabilities.

XMLHttpRequest Level 2 introduces new features like object cross-origin requests, progress events and handling byte streams for both sending and receiving channels. The standard (still a work in progress) will implement new attributes like “upload” and “withCredentials”  for client-server requests and also a “responseBody” attribute, “overrideMimeType()” method for server responses.

Level 2 will provide more event progress tracking for downloads, and uploads alike, with the usage of listeners put on the XMLHttpRequest object itself and “XMLHttpRequestUpload” object, returned by the “upload” attribute.

The Level 2 draft has been developed with HTML 5 standards in mind, with active involvement from the HTML 5 Working Group inside XMLHttpRequest Level 2 development.

The XMLHttpRequest Level 1 working draft can be found via this link.

The XMLHttpRequest Level 2 working draft is available here.