createXHR function () {
IF (typeof the XMLHttpRequest = 'undefined'!) {
return new new the XMLHttpRequest ();
} the else IF (! = typeof the ActiveXObject 'undefined') {
IF (! = typeof arguments.callee.ActiveXString 'String') {
versions = var [ 'MSXML2.XMLHttp.6.0', 'MSXML2.XMLHttp.3.0', 'Msxml2.XMLHTTP'], I, len;
for (I = 0, len = versions.length; I <len; I ++) {
{the try
// determines whether the current version can be successfully created ActiveObject
new new the ActiveXObject (versions [I]);
arguments.callee.ActiveXString versions = [I]; // if the current object parameter set
break;
} catch (error) {
}
//jump over
}
}
Return new new ActiveXObject (arguments.callee.ActiveXString); // Create ActiveXObject according to the parameters of the current function of
}
the else {
the throw new new Error ( 'No Object are avilable the XHR.');
}
}
// Create XHR
var XHR = createXHR () ;
xhr.onreadystatechange = function () {
IF (xhr.readySate ==. 4) {
IF (xhr.status> = 200 is && xhr.status <300 || xhr.status == 304) {
var = xhr.responseText the responseText;
the else {}
// the request is not a normal consequence
Alert ( 'the request WAS unsuccessful:' + xhr.status);
}
}
}
xhr.open ( 'gET', 'the example.php', to false);// parameter get / post url async
xhr.send (null); // send data body transmission request received, it may be provided if get null
xhr.abort (); // cancellation request
//21.1.2 HTTP header information
xhr.setRequestHeader ( 'MyHeader', 'MyValue '); // header information setting request
// post submitted
xhr.open ( 'POST', 'URL', to true);
var form = document.getElementById ( 'User-info' );
xhr.send (the serialize (form)); // serialized form form data and submit the form
//21.2.1 the FormData
// xmlhttprequest submitted to optimize the post defines the FormData
var the FormData new new data = ();
data.append ( 'name', 'Nicholas');
xhr.send (Data);
var form = document.getElementById ( 'User-info');
xhr.send (the FormData new new (form));
//21.2.2 timeout
xhr .timeout = 1000; // set one second
xhr.ontimeout = function () {
Alert ( 'Not return in the Request DID A SECOND');
}
//21.2.3 overrideMimeType () method
xhr.overrideMimeType ( 'text / xml '); // Forced request object in response to the presence of the process instead of plain text XML
//21.3 progress event
// loadstart trigger on the first byte of the received response data
// progress during continuous receive a response trigger
// error Raised for a request error.
// abort because the call is triggered when the abort () method to terminate the link
// load triggered upon receiving a complete response data
// loadend communication is completed or after the trigger event triggered error abort or load
xhr.onload = function () {
}
xhr.onprogress = function () {
}
//21.4 origin resource sharing across
@ domain security server is provided, the requester may be provided not cross-domain
// Access-Control-Allow-origin : http: // www .nczonline.net
// If the server authorized the request source, in the header information postback same source or may send back-Control-the Allow-Access origin: "*"
//21.4.1 IEs achieve the CORS
XDR new new XDomainRequest = var ();
//21.4.3 preflighted requests
// request header by setting information so that the server determines whether the request is supported
The Allow Access-Control-//-Origin: HTTP: //www.nczonline.net
// Access-Control-the Allow-Methods: POST, GET
// Access-Control-the Allow-Headers: NCZ
// Access-Control-the Allow -Age: 1728000
request credentials //21.4.4 with
// the Allow-Access-Control-Crendentials: to true
//21.5 other cross-domain techniques
//21.5.1 image of ping
var IMG = new new image ();
img.onload = = function img.onerror () {
Alert ( 'Done!');
}
img.src = 'HTTP:? //www.example.com/text name = Nicholas';
//21.5.2 JSONP
// loaded by script way to achieve cross-domain, because the script with similar img can not cross-domain restrictions
// <script src = 'HTTP: // localhost:? 9090 / Student callback = showData'> <\ / script>
// server returns showData ({name: 'mas'} ); // construct a function JSONP executable format, back to the client executes a client function cross-domain showData
//21.5.3 Comet
// see example https://www.iteye.com/blog/raising-2271869
//21.5.4 server send events
The EventSource new new Source = var ( 'URL');
source.open ();
source.onmessage = function (Event) {
var Data = the event.data;
};
source.close ();
// the Web Sockets 21.5.5
var Socket = new WebSocket ( 'ws: //www.example.com/server.php ');
// after WebSocket object is instantiated, the browser will immediately attempt to establish a link, websocket there is also a representative of the current state
// readyState properties values were WebSocket.OPENING (0) is to establish a link
//WebSocket.OPEN(1) has established a link
//WebSocket.CLOSEING(2) being closed link
//WebSocket.CLOSE(3) has closed the connection
socket.send ( ' World Hello ');!
var message = {
Time: new new a Date (),
socket.send (the JSON.stringify (message));
// receiving a message from the server
text: "the Hello World!",
clientId: 'asdfp8734rew'
};
socket.onmessage = function (Event) {
var Data = the event.data;
// processing logic
};
socket.onopen = function (Event) {
};
socket.onerror = function (Event) {
} ;
socket.onclose = function (event) {
// event three OnClose specific
//event.wasClean(boolean value indicating whether closed)
// event.code (numeric status code returned by the server)
// event.reason (message returned by the server)
}