jquery cross-Domain access solution

Client "cross-domain Access" has been a headache problem, fortunately, jquery help, from the jQuery-1.2 after the cross-domain problem will be solved. Because of the cross-domain problem in the project, I take this opportunity to find out the cross-domain problem, consult the relevant data and own practice, which solves the cross-domain problem. are recorded for inspection.
Jquery.ajax () supports the cross-domain of Get mode, which is actually done in Jsonp way.
Real Case:
$.ajax ({
Async:false,
URL: ' http://www.mysite.com/demo.do ',//cross-domain URL
Type: ' GET ',
DataType: ' Jsonp ',
JSONP: ' Jsoncallback ',//default callback
Data:mydata,
timeout:5000,
Beforesend:function () {//jsonp mode This method is not triggered. The reason may be that datatype, if specified as Jsonp, is not an AJAX event.
},
Success:function (JSON) {//client jquery pre-defined callback function, after successfully acquiring JSON data on a cross-domain server, this callback function is executed dynamically
if (json.actionerrors.length!=0) {
alert (json.actionerrors);
}
Gendynamiccontent (Qsdata,type,json);
},
Complete:function (XMLHttpRequest, Textstatus) {
$.unblockui ({fadeout:10});
},
Error:function (XHR) {
Jsonp mode This method is not triggered
Request Error Handling
Alert ("Request error (Please check correlation network status.)");
}
});

Attention:
$.getjson ("http://www.mysite.com/demo.do?name1=" +value1+ "&callback=?",
function (JSON) {
if (JSON. property name = = value) {
Execute code
}
});
This is actually a high-level package of the previous example $.ajax ({..}) API, and some of the $.ajax API's underlying parameters are encapsulated and not visible.

At the server end of the Request.getparameter ("callback"), the jquery end will be callback= back jsonp32440980
It then returns a similar: "jsonp32440980 (" + JSON array to return + ")";
jquery will invoke this by using the callback method to dynamically load: jsonp32440980 (JSON array);
This achieves the purpose of cross-domain data exchange.
Jsonp The basic principle is: Dynamic add one is consistent (QQ space is a large number of this way to achieve cross-domain data exchange). JSONP is a script injection (scripts injection) behavior, so there are some security implications.
Note: Jquey is not supported for post-mode cross-domain.
This is because although the use of post + dynamic generation of the IFRAME is possible to achieve the purpose of post cross-domain (there is a bit of JS Bull is this way to jquery1.2.5 patch), but this is a more extreme way, not recommended. It can also be said that the cross-domain get method is legal, post method from the security point of view is not legal, the last resort or not post,client end cross-domain access requirements seem to have attracted the attention of the world, see the data said HTML5 WebSocket standard support cross-domain data exchange, should also be a future-selectable solution for cross-domain data exchange.
Reference: http://www.jb51.net/article/21213.htm