5 ways to deal with js cross domain problems

Two days ago, I encountered a cross-domain problem, which can be solved by using jsonp. (# (link:))

Recently, I reorganized it:

1. The json.

    Ajax request, dataType jsonp. This form requires the request to be adjusted on the server to return a callback([json-object]). If the server returns a normal json object. When debugging, the chrome console will report an "Uncaught SyntaxError: Unexpected token" error. "SyntaxError: missing; "Before statement" error.

2. The iframe across domains.

    Add an iframe element to the page to set the SRC of the iframe to the url of the get request when a get request needs to be invoked.

var url = "http://xxx.xxx.xxx?p1=1&p2=2";

$("#iframe").attr("src", url);//Across domains, using iframe

The iframe approach is stronger than jsonp, and in addition to handling HTTP requests, it can also implement cross-domain js calls.

3. SRC attribute processing of script elements

    The SRC attributes of iframe, img, style, script and other elements can directly request resources from different domains. Jsonp is a simple implementation of cross-domain request resources by using script tags. Form.

var url="http://xxx.xxx.xxx?p1=1";

var script = document.createElement('script');

script.setAttribute('src', url);

document.getElementsByTagName('head')[0].appendChild(script);

4. Use get processing on the server.

    For the business does not require in the front end of the processing, you can do a encapsulation in the server side, and then the server side calls, so that the cross-domain problem can be solved. The code then USES either synchronous or asynchronous mode, depending on whether the request is sent or whether it needs to get a return value.

        private static void CreateGetHttpResponse(string url, int? timeout, string userAgent, CookieCollection cookies)

        {

            if (string.IsNullOrEmpty(url))

            {

                throw new ArgumentNullException("url");

            }

            var request = WebRequest.Create(url) as HttpWebRequest;

            request.Method = "GET";

            if (!string.IsNullOrEmpty(userAgent))

            {

                request.UserAgent = userAgent;

            }

            if (timeout.HasValue)

            {

                request.Timeout = timeout.Value;

            }

            if (cookies != null)

            {

                request.CookieContainer = new CookieContainer();

                request.CookieContainer.Add(cookies);

            }

            request.BeginGetResponse(null,null);//Asynchronous < br / >
            //return request.GetResponse() as HttpWebResponse;

        }

5. The flash across domains

Too sophisticated ==, more research

Summary: the above five methods are the common way to solve the js cross-domain problem, the last one is more high-end, I will make up for it.