JQuery ajax call default timeout value

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最佳答案

There doesn't seem to be a standardized default value. I have the feeling the default is 0, and the timeout event left totally dependent on browser and network settings.

For IE, there is a timeout property for XMLHTTPRequests here. It defaults to null, and it says the network stack is likely to be the first to time out (which will not generate an ontimeout event by the way).

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As an aside, when trying to diagnose a similar bug I realised that jquery's ajax error callback returns a status of "timeout" if it failed due to a timeout.

Here's an example:

$.ajax({
url: "/ajax_json_echo/",
timeout: 500,
error: function(jqXHR, textStatus, errorThrown) {
alert(textStatus); // this will be "timeout"
}
});

Here it is on jsfiddle.

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there is no timeout, by default.

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The XMLHttpRequest.timeout property represents a number of milliseconds a request can take before automatically being terminated. The default value is 0, which means there is no timeout. An important note the timeout shouldn't be used for synchronous XMLHttpRequests requests, used in a document environment or it will throw an InvalidAccessError exception. You may not use a timeout for synchronous requests with an owning window.

IE10 and 11 do not support synchronous requests, with support being phased out in other browsers too. This is due to detrimental effects resulting from making them.

More info can be found here.

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Please refer to this api info.

timeout
Type: Number
Set a timeout (in milliseconds) for the request. A value of 0 means there
will be no timeout. This will override any global timeout set with
$.ajaxSetup(). The  timeout period starts at the point the $.ajax call is made;
if several other  requests are in progress and the browser has no connections
available, it is  possible for a request to time out before it can be sent. In
jQuery 1.4.x and  below, the XMLHttpRequest object will be in an invalid state if
the request  times out; accessing any object members may throw an exception. In
Firefox 3.0+  only, script and JSONP requests cannot be cancelled by a timeout;
the script  will  run even if it arrives after the timeout period.