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This time I will bring you a detailed explanation of the steps to implement JS cross-domain POST. What are the precautions for JS cross-domain POST implementation? Here are practical cases, let’s take a look.
javascript Cross-domain is a very common problem, among which jsonp is the most commonly used method, but jsonp only supports get, not post, so if you want to post some data through jsonp , the head is big.
Post is implemented by generating a form in an iframe, and returns the value to the caller through postMessage.
In the first step, we first implement a back-end code that accepts jsonp. As for what language to use for implementation, you decide for yourself.
c#The code is:
protected void Page_Load(object sender, EventArgs e)
{
StringBuilder sbRet = new StringBuilder();
sbRet.Append("<script>");
sbRet.Append(Request["jsoncallback"]);
sbRet.Append("({");
foreach (string k in Request.Form) {
if (k == "jsoncallback") continue;
sbRet.Append("'"+k+"':'"+Request.Form[k]+"'");
}
sbRet.Append("});");
sbRet.Append("</script>");
Response.Write(sbRet.ToString());
Response.End();
}
For example, what you want to return to me is { userName:'user1', password:'pass1' } , when I call http://localhost/test When ?jsoncallback=callme
you actually return<script>callme({ userName:'user1', password:'pass1' })</script>.
The second step is to build a post test page in the local folder, such as d:\test.html
<form action="http://localhost/test" method="post"> <input type="text" name="userName" value="user1" /> <input type="text" name="password" value="pass1" /> <input type="text" name="jsoncallback" value="callme" /> <input type="submit" value="提交" /> </form>
The third step is to browse and click submit to see if the returned value is < ;script>callme({ userName:'user1', password:'pass1' }) means there is no problem with the back-end program.
The fourth step, we write a general code to implement the above html.
<!doctype html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>测试一哈</title>
</head>
<body>
<script>
//源码 开始
function postJSONP(url, data, callback) {
var template = '<form action="{{url}}" method="post" id="form1">';
for (var k in data) {
template = template
+ ' <input type="text" name="'+k+'" value="'+data[k]+'" />'
}
template = template
+ ' <input type="text" name="jsoncallback" value="function callback(data) { parent.postMessage(data, \'*\'); } callback" />'
+ '</form>'
+ '<'+'script>'
+ 'document.getElementById("form1").submit();'
+ '</'+'script>';
template = template.replace("{{url}}", url);
var p = document.createElement("p");
p.style.display = 'none';
p.innerHTML = '<iframe src=""></iframe>';
document.body.appendChild(p);
var ifrm = p.children[0];
var cwin = ifrm.contentWindow;
cwin.document.write(template);
window.onmessage = function(e) {
if (callback) callback(e.data);
}
}
//源码 结束
//使用测试
window.onload = function() {
postJSONP('http://localhost:59898/WebForm1.aspx', { userName: '张静', password: '就不告诉你' }, function(data) {
console.log(11, data);
});
postJSONP('http://localhost:59898/WebForm1.aspx', { 仓库: '1号大仓', 面积: '2万平米' }, function(data) {
console.log(22, data);
});
}
</script>
</body>
</html>
The fifth step, security issues,
window.onmessage = function(e) {
//可通过 e 来判断来源，并做一些安全方面的处理，此处读者自己去研究吧，可以加个 console.log(e) 看看 e 有哪些内容。
if (callback) callback(e.data);
}
I believe you have read the case in this article After mastering the method, please pay attention to other related articles on the php Chinese website for more exciting content!
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