AJAX和Python錯誤 - 請求的資源上沒有「Access-Control-Allow-Origin」標頭

Question

我正在構建一個Javascript庫，可以使用AJAX與簡單的Python Web服務器通信。

這裏是Web服務器類：

class WebHandler(http.server.BaseHTTPRequestHandler): 

    def parse_POST(self): 
     ctype, pdict = cgi.parse_header(self.headers['content-type']) 
     if ctype == 'multipart/form-data': 
      postvars = cgi.parse_multipart(self.rfile, pdict) 
     elif ctype == 'application/x-www-form-urlencoded': 
      length = int(self.headers['content-length']) 
      postvars = urllib.parse.parse_qs(self.rfile.read(length), 
              keep_blank_values=1) 
     else: 
      postvars = {} 
     return postvars 

    def do_POST(self): 
     postvars = self.parse_POST() 

     print(postvars) 

     # reply with JSON 
     self.send_response(200) 
     self.send_header("Content-type", "application/json") 
     self.end_headers() 
     json_response = json.dumps({'test': 42}) 
     self.wfile.write(bytes(json_response, "utf-8")) 

這裏是JavaScript方法我用：

var send_action = function() { 
    var url = "http://192.168.1.51:8000"; 
    var post_data = {'gorilla': 'man'}; 

    $.post(url, post_data, function(data) { 
     alert("success"); 

    }) 
     .done(function(data) { 
     alert("second success"); 

    }) 
     .fail(function() { 
     alert("error"); 

    }) 
     .always(function() { 
     alert("finished"); 
    }); 
}; 

當我運行的服務器，並調用JS功能服務器輸出{'gorilla': 'man'}但隨後瀏覽器閃爍錯誤警報，然後完成警報。在開發者日誌中我有：

$.post(url, post_data, function(data) { 
    alert("success"); 
}, 'json') 

或

$.post(url, post_data, function(data) { 
    alert("success"); 
}, 'jsonp') 

無論是服務器和：

XMLHttpRequest cannot load http://192.168.1.51:8000/. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access. 

，當我在$.post指定*的dataType *就像於是同樣的事情發生瀏覽器會話在同一臺機器上。

解決方案

所需self.send_header("Content-type", "application/json")後添加額外的頭：

self.send_header("Access-Control-Allow-Origin", "*"); 
self.send_header("Access-Control-Expose-Headers", "Access-Control-Allow-Origin"); 
self.send_header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"); 

Answer 1

有很多關於主題：訪問控制允許來源。瞭解更多：http://en.wikipedia.org/wiki/Same_origin_policy

後添加此行：self.send_header("Content-type", "application/json")

self.send_header("Access-Control-Allow-Origin","*"); 
self.send_header("Access-Control-Expose-Headers: Access-Control-Allow-Origin"); 
self.send_header(("Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept");