无法使用JavaScript访问json文件 [英] Cannot access json file with javascript

问题描述

我想阅读本页面的json内容： http://89.92.40.250:8010/dreamteam/interface/get_event_detail.php?id=397 with javascript 。

所以我开始这个脚本：

  var req = new XMLHttpRequest （）; 
 req.open（GET，http://89.92.40.250:8010/dreamteam/interface/get_event_detail.php?id=397，true）; 
 req.onreadystatechange = monCode; 
 req.send（null）; 
 
函数monCode（）{
 if（req.readyState == 4）{
 var doc = eval（'（'+ req.responseText +'）'）; 
 alert（req.responseText）; 
} 
} 
  

当我想显示我使用alert req.responseText）;我没有看到内容。另外，我用Firebug语法错误：语法错误：var doc = eval（'（'+ req.responseText +'）'）;

不可能使用JSONP。 / p>

我们可以提取页面的内容，然后将其转换为JSON格式，然后解析它？

解决方案

如果您无法创建自己的代理，则应该使用YQL来避免跨域问题。

这里是一个示例url for id = 397 ，

  http：//query.yahooapis。 COM / V1 /公共/ YQL q =选择％20 *％20from％20json％20where％20url％3D'http％3A％2F％2F89.92.40.250％3A8010％2Fdreamteam％2Finterface％2Fget_event_detail.php％3Fid％3D397 '& format = json& diagnostics = true 
  

你可以像这样动态设置id， p>

  var id = 397; 
 var baseurl =http://query.yahooapis.com/v1/public/yql?q=; 
 var q =select * from json where url ='http://89.92.40.250:8010/dreamteam/interface/get_event_detail.php?id=\"+id+'; 
 var url = baseurl + encodeURI（q）+& format = json& diagnostics = true; 
 var req = new XMLHttpRequest（）; 
 req.open（GET，url，true）; 
 req.onreadystatechange = monCode; 
 req.send（null）; 
 
函数monCode（）{
 if（req.readyState == 4）{
 var data = JSON.parse（req.responseText）.query.results; 
 console.log（data）; 
 //console.log(data.event）; 
 alert（data.event.title）; 
 
 
  

和这是一个jsFiddle DEMO

YQL的使用限制

• 每个应用程序限制访问密钥）：每天100,000个呼叫


• 每个IP限制：/ v1 / public / ：每小时2000个呼叫; / v1 / yql / ：每小时20,000个电话

I want to read the json content of this page : http://89.92.40.250:8010/dreamteam/interface/get_event_detail.php?id=397 with javascript.

So i began this script :

var req = new XMLHttpRequest();
    req.open("GET", "http://89.92.40.250:8010/dreamteam/interface/get_event_detail.php?id=397", true); 
    req.onreadystatechange = monCode;   
    req.send(null);      

    function monCode() { 
        if (req.readyState == 4) { 
            var doc = eval('(' + req.responseText + ')');
            alert(req.responseText);
        }
    } 

when I want to show the content I use alert(req.responseText); and I don't see the content. Plus I have a syntax error with Firebug : syntax error : var doc = eval('(' + req.responseText + ')');

Impossible with JSONP.

Can we extract the content of the page, then convert it to JSON format then parse it ??

解决方案

If you can't create a your own proxy, you should use YQL to avoid cross domain problem.

here is an example url for id=397,

http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20json%20where%20url%3D'http%3A%2F%2F89.92.40.250%3A8010%2Fdreamteam%2Finterface%2Fget_event_detail.php%3Fid%3D397'&format=json&diagnostics=true

and you can set id dynamically like this,

var id = 397;
var baseurl = "http://query.yahooapis.com/v1/public/yql?q=";
var q = "select * from json where url = 'http://89.92.40.250:8010/dreamteam/interface/get_event_detail.php?id="+id+"'";  
var url = baseurl + encodeURI(q) + "&format=json&diagnostics=true";
var req = new XMLHttpRequest();
req.open("GET", url, true);
req.onreadystatechange = monCode;
req.send(null);

function monCode() {
    if (req.readyState == 4) {
        var data = JSON.parse(req.responseText).query.results;
        console.log(data);
        //console.log(data.event);
        alert(data.event.title);
    }
}​

And here is a jsFiddle DEMO

Usage Limits for YQL

• Per application limit (identified by your Access Key): 100,000 calls per day
• Per IP limits: /v1/public/: 2,000 calls per hour; /v1/yql/: 20,000 calls per hour

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