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/**
* Register ajax transports for blob send/recieve and array buffer send/receive via XMLHttpRequest Level 2
* within the comfortable framework of the jquery ajax request, with full support for promises.
*
* Notice the +* in the dataType string? The + indicates we want this transport to be prepended to the list
* of potential transports (so it gets first dibs if the request passes the conditions within to provide the
* ajax transport, preventing the standard transport from hogging the request), and the * indicates that
* potentially any request with any dataType might want to use the transports provided herein.
*
* Remember to specify 'processData:false' in the ajax options when attempting to send a blob or arraybuffer -
* otherwise jquery will try (and fail) to convert the blob or buffer into a query string.
*/
$.ajaxTransport("+*", function(options, originalOptions, jqXHR){
// Test for the conditions that mean we can/want to send/receive blobs or arraybuffers - we need XMLHttpRequest
// level 2 (so feature-detect against window.FormData), feature detect against window.Blob or window.ArrayBuffer,
// and then check to see if the dataType is blob/arraybuffer or the data itself is a Blob/ArrayBuffer
if (window.FormData && ((options.dataType && (options.dataType === 'blob' || options.dataType === 'arraybuffer')) ||
(options.data && ((window.Blob && options.data instanceof Blob) ||
(window.ArrayBuffer && options.data instanceof ArrayBuffer)))
))
{
return {
/**
* Return a transport capable of sending and/or receiving blobs - in this case, we instantiate
* a new XMLHttpRequest and use it to actually perform the request, and funnel the result back
* into the jquery complete callback (such as the success function, done blocks, etc.)
*
* @param headers
* @param completeCallback
*/
send: function(headers, completeCallback){
var xhr = new XMLHttpRequest(),
url = options.url || window.location.href,
type = options.type || 'GET',
dataType = options.dataType || 'text',
data = options.data || null,
async = options.async || true,
key;
xhr.addEventListener('load', function(){
var response = {}, status, isSuccess;
isSuccess = xhr.status >= 200 && xhr.status < 300 || xhr.status === 304;
if (isSuccess) {
response[dataType] = xhr.response;
} else {
// In case an error occured we assume that the response body contains
// text data - so let's convert the binary data to a string which we can
// pass to the complete callback.
response.text = String.fromCharCode.apply(null, new Uint8Array(xhr.response));
}
completeCallback(xhr.status, xhr.statusText, response, xhr.getAllResponseHeaders());
});
xhr.open(type, url, async);
xhr.responseType = dataType;
for (key in headers) {
if (headers.hasOwnProperty(key)) xhr.setRequestHeader(key, headers[key]);
}
xhr.send(data);
},
abort: function(){
jqXHR.abort();
}
};
}
});
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