javascript 纯JS获取Json数组
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Get Json Array with pure JS
提问by Mark Karan
I would like to get JSON Array from a cross domain without using JQuery. The data from cross domain is like this:
我想在不使用 JQuery 的情况下从跨域获取 JSON 数组。跨域的数据是这样的：
{
"transactionid": "LBS_48550801",
"status": 0,
"countrylist":
[
{ "id": 1, "name": "France", "latitude": 37.00039, "longitude": 35.31411, "extent": { "minlatitude": 36.53888499, "minlongitude": 34.76786904, "maxlatitude": 38.37851496, "maxlongitude": 36.40534884 }},
{ "id": 2, "name": "Germany", "latitude": 37.76454, "longitude": 38.27645, "extent": { "minlatitude": 37.40771898, "minlongitude": 37.43326512, "maxlatitude": 38.21203404, "maxlongitude": 39.24767592 } },
//... .... ....
//... .... ....
//... .... ....
{ "id": 98, "name": "Belgium", "latitude": 38.75754, "longitude": 30.5387, "extent": { "minlatitude": 37.78126803, "minlongitude": 29.68963308, "maxlatitude": 39.27915099, "maxlongitude": 31.71549708 } },
{ "id": 99, "name": "England", "latitude": 39.71812, "longitude": 43.03345, "extent": { "minlatitude": 38.96877501, "minlongitude": 42.28340184, "maxlatitude": 40.031208, "maxlongitude": 44.61092892 } },
]
}
After getting the data, I need to parse it to get "countrylist" list.
获取数据后，我需要对其进行解析以获取“国家/地区列表”列表。
I searched for solving this issue but the examples are all with JQuery. I dont want to use it. As you see, I have transactionid, status parameters in the input. So, after importing the data, I need to parse it to get the countrylist array. I know how to parse it, but I couldnt get the whole data from the service.
我搜索了解决此问题的方法，但示例均使用 JQuery。我不想使用它。如您所见，我在输入中有 transactionid、status 参数。因此，在导入数据后，我需要对其进行解析以获取 countrylist 数组。我知道如何解析它，但我无法从服务中获取全部数据。
I need to get the data by Javascript methods. The server supports retrieving data well.
我需要通过 Javascript 方法获取数据。服务器很好地支持检索数据。
The steps to be taken are:
要采取的步骤是：
1- Get the whole data (Here is where I got stuck)
1-获取整个数据（这是我卡住的地方）
2- Parse it as Json Object (I know how to parse the data)
2- 将其解析为 Json 对象（我知道如何解析数据）
How can I get the whole data without using any JQuery or other prepared libraries?
如何在不使用任何 JQuery 或其他准备好的库的情况下获取整个数据？
回答by kmakarychev
You can use XMLHttpRequest for ajax and JSON.parse for parse json :)
您可以将 XMLHttpRequest 用于 ajax 和 JSON.parse 用于解析 json :)
var xmlhttp = new XMLHttpRequest();
xmlhttp.open('GET', '//example.org', true);
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4) {
if(xmlhttp.status == 200) {
var obj = JSON.parse(xmlhttp.responseText);
var countryList = obj.countrylist;
}
}
};
xmlhttp.send(null);
You should never use eval! Eval is evil! You can read about it on mdn
你永远不应该使用 eval！Eval是邪恶的！你可以在mdn上阅读它
UPD:
更新：
If there is no CORS header, you can use JSONP. Just add &callback=getJSONPto your URL. Try it on jsfiddle: http://jsfiddle.net/VmBF7/3/
如果没有 CORS 标头，则可以使用 JSONP。只需添加&callback=getJSONP到您的网址。在 jsfiddle 上试试：http: //jsfiddle.net/VmBF7/3/
回答by denolk
since your operation involving cross domain requests, i suggest you to use jsonp request.
由于您的操作涉及跨域请求，我建议您使用 jsonp 请求。
this questionhas what you wanted.
这个问题有你想要的。
回答by shellbye
In my case, since the server require a ajaxrequest or it will give you a 404(to prevent csrf), so based on what the accepted answer, you need one extra line to complete the getJSONajax version like this:
在我的情况下，由于服务器需要一个ajax请求或者它会给你一个 404（以防止csrf），所以根据接受的答案，你需要额外的一行来完成这样的getJSONajax 版本：
<script type="application/javascript">
var request = new XMLHttpRequest();
request.open('GET', '/your/url', true);
// this following line is needed to tell the server this is a ajax request
request.setRequestHeader("X-Requested-With", "XMLHttpRequest");
request.onload = function () {
if (this.status >= 200 && this.status < 400) {
var json = JSON.parse(this.response);
// this is where you can do something with the json response
}
};
request.send();
});
</script>
回答by Jorge_B
Could you try to download the data to a hidden iframe and then parse the content of its document.body?
您能否尝试将数据下载到隐藏的 iframe，然后解析其 document.body 的内容？
