Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
Obsolete since Gecko 22
This Gecko-only feature was removed in Firefox/Gecko 22. Please use Server-Sent Events, Web Sockets, or responseText from progress events instead.
This boolean indicates if the response is expected to be a stream of possibly multiple XML documents. If set to true, the content type of the initial response must be multipart/x-mixed-replace or an error will occur. All requests must be asynchronous.
This enables support for server push; for each XML document that's written to this request, a new XML DOM document is created and the onload handler is called between documents.
Note: When this is set, the onload handler and other event handlers are not reset after the first XMLdocument is loaded, and the onload handler is called after each part of the response is received.