Native JS implements Ajax cross-domain request flask response content (graphic tutorial)-JS Tutorial-php.cn

Native JS implements Ajax cross-domain request flask response content (graphic tutorial)

亚连

Release： 2018-05-22 09:37:59

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This article mainly introduces the JS implementation of Ajax cross-domain request flask response content in detail. It has a certain reference value. Interested friends can refer to it

The Ajax method is good and the website feels like It's high-end, but due to the limitations of Js, cross-domain Ajax cannot be implemented. Here, let's talk about the solution. The premise is that you need to be able to control the response on the flask side.

Main technology:

Modify the corresponding header of the server so that it can correspond to any domain name. and sets the response header so that it can correspond to the POST method.

Implementation code:

Put the flask code here first:

from flask import make_response
@app.route(&#39;/test&#39;,methods=[&#39;get&#39;,&#39;post&#39;])
def Test():
 if request.method==&#39;GET&#39;:
  rst = make_response(&#39;aaa&#39;)
  rst.headers[&#39;Access-Control-Allow-Origin&#39;] = &#39;*&#39; #任意域名
  return rst
 else:
  rst = make_response(&#39;bbb&#39;)
  rst.headers[&#39;Access-Control-Allow-Origin&#39;] = &#39;*&#39;
  rst.headers[&#39;Access-Control-Allow-Methods&#39;] = &#39;POST&#39; #响应POST
  return rst

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html test code:

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>Title</title>
</head>
<body>
<span id="ss">test get</span>
<button onclick="getAjax()">click</button>

 <p id="time">test post</p>
 <input type="submit" value="click" onclick="getPostAjax()">


<script>
 function getPostAjax() {
  var xmlhttp = new XMLHttpRequest();
  xmlhttp.onreadystatechange=function () {
   if(xmlhttp.readyState=4 && xmlhttp.status ==200 ) {
    document.getElementById("time").innerText = xmlhttp.responseText;
   }
  }

  xmlhttp.open("POST","http://localhost:5000/test",true);
  xmlhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
  #这句话可以发送post数据，没有此句post的内容无法传递
  xmlhttp.send();


 }

 function getAjax() {
  var xmlhttp = new XMLHttpRequest();
  xmlhttp.onreadystatechange=function () {
   if(xmlhttp.readyState==4 && xmlhttp.status == 200){
    document.getElementById("ss").innerHTML=xmlhttp.responseText;
   }
  }
  xmlhttp.open("GET","http://localhost:5000/test",true);
  xmlhttp.send();
 }
</script>
</body>
</html>

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Unable to control the response header

For In this case, the get request can be completed using jquery, but there is nothing you can do about post. Currently, I am writing both the front and back ends, so I will not consider this situation for the time being.

The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.

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