我需要在JavaScript中做一个HTTP GET请求。最好的方法是什么?
我需要在Mac OS X的dashcode小部件中做到这一点。
我需要在JavaScript中做一个HTTP GET请求。最好的方法是什么?
我需要在Mac OS X的dashcode小部件中做到这一点。
当前回答
// Create a request variable and assign a new XMLHttpRequest object to it.
var request = new XMLHttpRequest()
// Open a new connection, using the GET request on the URL endpoint
request.open('GET', 'restUrl', true)
request.onload = function () {
// Begin accessing JSON data here
}
// Send request
request.send()
其他回答
<button type="button" onclick="loadXMLDoc()"> GET CONTENT</button>
<script>
function loadXMLDoc() {
var xmlhttp = new XMLHttpRequest();
var url = "<Enter URL>";``
xmlhttp.onload = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == "200") {
document.getElementById("demo").innerHTML = this.responseText;
}
}
xmlhttp.open("GET", url, true);
xmlhttp.send();
}
</script>
对于那些使用AngularJs的人来说,它是$http.get:
$http.get('/someUrl').
success(function(data, status, headers, config) {
// this callback will be called asynchronously
// when the response is available
}).
error(function(data, status, headers, config) {
// called asynchronously if an error occurs
// or server returns response with an error status.
});
// Create a request variable and assign a new XMLHttpRequest object to it.
var request = new XMLHttpRequest()
// Open a new connection, using the GET request on the URL endpoint
request.open('GET', 'restUrl', true)
request.onload = function () {
// Begin accessing JSON data here
}
// Send request
request.send()
IE会缓存URL以加快加载速度,但如果你每隔一段时间轮询服务器以获取新信息,IE会缓存URL,并可能返回你一直拥有的相同数据集。
无论您最终如何执行GET请求——普通JavaScript、Prototype、jQuery等等——都要确保您设置了一种机制来对抗缓存。为了解决这个问题,在你要访问的URL末尾附加一个唯一的标记。这可以通过:
var sURL = '/your/url.html?' + (new Date()).getTime();
这将在URL的末尾附加一个唯一的时间戳,并将防止发生任何缓存。
你也可以用纯JS来做:
// Create the XHR object.
function createCORSRequest(method, url) {
var xhr = new XMLHttpRequest();
if ("withCredentials" in xhr) {
// XHR for Chrome/Firefox/Opera/Safari.
xhr.open(method, url, true);
} else if (typeof XDomainRequest != "undefined") {
// XDomainRequest for IE.
xhr = new XDomainRequest();
xhr.open(method, url);
} else {
// CORS not supported.
xhr = null;
}
return xhr;
}
// Make the actual CORS request.
function makeCorsRequest() {
// This is a sample server that supports CORS.
var url = 'http://html5rocks-cors.s3-website-us-east-1.amazonaws.com/index.html';
var xhr = createCORSRequest('GET', url);
if (!xhr) {
alert('CORS not supported');
return;
}
// Response handlers.
xhr.onload = function() {
var text = xhr.responseText;
alert('Response from CORS request to ' + url + ': ' + text);
};
xhr.onerror = function() {
alert('Woops, there was an error making the request.');
};
xhr.send();
}
详见:html5rocks教程