initializes a newly-created request, or re-initializes an existing one.
Note: Calling this method for an already active request
(one for which
open() has already been called) is the equivalent of calling
open(method, url) open(method, url, async) open(method, url, async, user) open(method, url, async, user, password)
The HTTP request method to use, such as
"DELETE", etc. Ignored for non-HTTP(S) URLs.
An optional Boolean parameter, defaulting to
true, indicating whether or not to perform the operation asynchronously. If this value is
send()method does not return until the response is received. If
true, notification of a completed transaction is provided using event listeners. This must be true if the
true, or an exception will be thrown.
Note: Synchronous requests on the main thread can be easily disruptive to the user experience and should be avoided; in fact, many browsers have deprecated synchronous XHR support on the main thread entirely. Synchronous requests are permitted in
The optional user name to use for authentication purposes; by default, this is the
The optional password to use for authentication purposes; by default, this is the
|XMLHttpRequest Standard |
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