JavaScript中的HTTP GET请求？
我需要用JavaScript做一个请求。最好的方法是什么 我需要在Mac OS X dashcode小部件中执行此操作。JavaScript中的HTTP GET请求？,javascript,http-get,dashcode,Javascript,Http Get,Dashcode,我需要用JavaScript做一个请求。最好的方法是什么 我需要在Mac OS X dashcode小部件中执行此操作。 最好使用或之类的库。下面是直接用JavaScript实现的代码。但是，正如前面提到的，使用JavaScript库会更好。我最喜欢的是jQuery 在下面的例子中，调用一个ASPX页面（作为穷人的REST服务）来返回一个JavaScript JSON对象 var xmlHttp = null; function GetCustomerInfo() { var Cust
最好使用或之类的库。下面是直接用JavaScript实现的代码。但是，正如前面提到的，使用JavaScript库会更好。我最喜欢的是jQuery 在下面的例子中，调用一个ASPX页面（作为穷人的REST服务）来返回一个JavaScript JSON对象
var xmlHttp = null;
function GetCustomerInfo()
{
var CustomerNumber = document.getElementById( "TextBoxCustomerNumber" ).value;
var Url = "GetCustomerInfoAsJson.aspx?number=" + CustomerNumber;
xmlHttp = new XMLHttpRequest();
xmlHttp.onreadystatechange = ProcessRequest;
xmlHttp.open( "GET", Url, true );
xmlHttp.send( null );
}
function ProcessRequest()
{
if ( xmlHttp.readyState == 4 && xmlHttp.status == 200 )
{
if ( xmlHttp.responseText == "Not found" )
{
document.getElementById( "TextBoxCustomerName" ).value = "Not found";
document.getElementById( "TextBoxCustomerAddress" ).value = "";
}
else
{
var info = eval ( "(" + xmlHttp.responseText + ")" );
// No parsing necessary with JSON!
document.getElementById( "TextBoxCustomerName" ).value = info.jsonData[ 0 ].cmname;
document.getElementById( "TextBoxCustomerAddress" ).value = info.jsonData[ 0 ].cmaddr1;
}
}
}
new Ajax.Request( '/myurl', {
method: 'get',
parameters: { 'param1': 'value1'},
onSuccess: function(response){
alert(response.responseText);
},
onFailure: function(){
alert('ERROR');
}
});
IE将缓存URL以加快加载速度，但如果您（比如）每隔一段时间轮询服务器以获取新信息，IE将缓存该URL并可能返回您一直拥有的相同数据集 无论最终如何执行GET请求（香草JavaScript、Prototype、jQuery等），都要确保设置了一种机制来对抗缓存。为了解决这个问题，在你要点击的URL的末尾附加一个唯一的标记。这可以通过以下方式实现：
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，并防止任何缓存发生。在您的小部件的Info.plist文件中，不要忘记将您的
AllowNetworkAccess在这种情况下，AJAX是一种可行的方法。这就是我两年来javascript的繁重开发 我不熟悉Mac OS Dashcode小部件，但如果它们允许您使用JavaScript库和支持，我会使用并执行以下操作：
var page_content;
$.get( "somepage.php", function(data){
page_content = data;
});
Property1: value
Property2: value
etc.
如果您希望使用仪表板小部件的代码，并且不希望在创建的每个小部件中都包含JavaScript库，那么可以使用Safari本机支持的对象XMLHttpRequest 正如Andrew Hedges所报道的，默认情况下，小部件无法访问网络；您需要在与小部件关联的info.plist中更改该设置。浏览器（和Dashcode）提供一个XMLHttpRequest对象，可用于从JavaScript发出HTTP请求：
function httpGet(theUrl)
{
var xmlHttp = new XMLHttpRequest();
xmlHttp.open( "GET", theUrl, false ); // false for synchronous request
xmlHttp.send( null );
return xmlHttp.responseText;
}
function httpGetAsync(theUrl, callback)
{
var xmlHttp = new XMLHttpRequest();
xmlHttp.onreadystatechange = function() {
if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
callback(xmlHttp.responseText);
}
xmlHttp.open("GET", theUrl, true); // true for asynchronous
xmlHttp.send(null);
}
没有回调的版本
var i = document.createElement("img");
i.src = "/your/GET/url?params=here";
上面有很多很好的建议，但不是很好的重用，而且常常充满了DOM胡说八道和其他隐藏简单代码的漏洞 下面是我们创建的一个Javascript类，它是可重用且易于使用的。目前它只有一个GET方法，但这对我们来说是有效的。添加一个帖子不应该影响任何人的技能
var HttpClient = function() {
this.get = function(aUrl, aCallback) {
var anHttpRequest = new XMLHttpRequest();
anHttpRequest.onreadystatechange = function() {
if (anHttpRequest.readyState == 4 && anHttpRequest.status == 200)
aCallback(anHttpRequest.responseText);
}
anHttpRequest.open( "GET", aUrl, true );
anHttpRequest.send( null );
}
}
var client = new HttpClient();
client.get('http://some/thing?with=arguments', function(response) {
// do something with response
});
您可以通过两种方式获取HTTP get请求：
xmlhttp.open("GET","URL",true);
xmlhttp.send();
$("btn").click(function() {
$.ajax({url: "demo_test.txt", success: function_name(result) {
$("#innerdiv").html(result);
}});
});
$http.get$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.
});
看看这个链接吧新的API是使用ES6承诺的
XMLHttpRequest一个支持旧浏览器的解决方案：
function httpRequest() {
var ajax = null,
response = null,
self = this;
this.method = null;
this.url = null;
this.async = true;
this.data = null;
this.send = function() {
ajax.open(this.method, this.url, this.asnyc);
ajax.send(this.data);
};
if(window.XMLHttpRequest) {
ajax = new XMLHttpRequest();
}
else if(window.ActiveXObject) {
try {
ajax = new ActiveXObject("Msxml2.XMLHTTP.6.0");
}
catch(e) {
try {
ajax = new ActiveXObject("Msxml2.XMLHTTP.3.0");
}
catch(error) {
self.fail("not supported");
}
}
}
if(ajax == null) {
return false;
}
ajax.onreadystatechange = function() {
if(this.readyState == 4) {
if(this.status == 200) {
self.success(this.responseText);
}
else {
self.fail(this.status + " - " + this.statusText);
}
}
};
}
您也可以使用纯JS实现这一点：
// 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();
}
请参阅：了解更多详细信息：简洁明了：
consthttp=newxmlhttprequest（）
http.open（“GET”https://api.lyrics.ovh/v1/toto/africa")
http.send（）
http.onload=（）=>console.log（http.responseText）let httpRequestAsync = (method, url) => {
return new Promise(function (resolve, reject) {
var xhr = new XMLHttpRequest();
xhr.open(method, url);
xhr.onload = function () {
if (xhr.status == 200) {
resolve(xhr.responseText);
}
else {
reject(new Error(xhr.responseText));
}
};
xhr.send();
});
}
为此，建议使用JavaScript承诺使用fetchapi。XMLHttpRequest（XHR）、IFrame对象或动态标记是较旧（且较笨重）的方法
<script type=“text/javascript”>
// Create request object
var request = new Request('https://example.com/api/...',
{ method: 'POST',
body: {'name': 'Klaus'},
headers: new Headers({ 'Content-Type': 'application/json' })
});
// Now use it!
fetch(request)
.then(resp => {
// handle response })
.catch(err => {
// handle errors
}); </script>
//创建请求对象
var请求=新请求（'https://example.com/api/...',
{方法：'POST'，
正文：{'name'：'Klaus'}，
标题：新标题（{'Content-Type'：'application/json'}）
});
//现在使用它！
提取（请求）
.然后（resp=>{
//句柄响应}）
.catch（错误=>{
//处理错误
});
function get(url, callback) {
var getRequest = new XMLHttpRequest();
getRequest.open("get", url, true);
getRequest.addEventListener("readystatechange", function() {
if (getRequest.readyState === 4 && getRequest.status === 200) {
callback(getRequest.responseText);
}
});
getRequest.send();
}
这里是xml文件的另一种选择，可以将文件作为对象加载，并以非常快速的方式作为对象访问属性
- 请注意，为了让javascript能够正确解释内容，有必要将文件保存为与HTML页面相同的格式。如果您使用UTF8，请使用UTF8等格式保存文件
function httpRequest() {
var ajax = null,
response = null,
self = this;
this.method = null;
this.url = null;
this.async = true;
this.data = null;
this.send = function() {
ajax.open(this.method, this.url, this.asnyc);
ajax.send(this.data);
};
if(window.XMLHttpRequest) {
ajax = new XMLHttpRequest();
}
else if(window.ActiveXObject) {
try {
ajax = new ActiveXObject("Msxml2.XMLHTTP.6.0");
}
catch(e) {
try {
ajax = new ActiveXObject("Msxml2.XMLHTTP.3.0");
}
catch(error) {
self.fail("not supported");
}
}
}
if(ajax == null) {
return false;
}
ajax.onreadystatechange = function() {
if(this.readyState == 4) {
if(this.status == 200) {
self.success(this.responseText);
}
else {
self.fail(this.status + " - " + this.statusText);
}
}
};
}
//create request with its porperties
var request = new httpRequest();
request.method = "GET";
request.url = "https://example.com/api?parameter=value";
//create callback for success containing the response
request.success = function(response) {
console.log(response);
};
//and a fail callback containing the error
request.fail = function(error) {
console.log(error);
};
//and finally send it away
request.send();
// 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();
}
let httpRequestAsync = (method, url) => {
return new Promise(function (resolve, reject) {
var xhr = new XMLHttpRequest();
xhr.open(method, url);
xhr.onload = function () {
if (xhr.status == 200) {
resolve(xhr.responseText);
}
else {
reject(new Error(xhr.responseText));
}
};
xhr.send();
});
}
<script type=“text/javascript”>
// Create request object
var request = new Request('https://example.com/api/...',
{ method: 'POST',
body: {'name': 'Klaus'},
headers: new Headers({ 'Content-Type': 'application/json' })
});
// Now use it!
fetch(request)
.then(resp => {
// handle response })
.catch(err => {
// handle errors
}); </script>
function get(url, callback) {
var getRequest = new XMLHttpRequest();
getRequest.open("get", url, true);
getRequest.addEventListener("readystatechange", function() {
if (getRequest.readyState === 4 && getRequest.status === 200) {
callback(getRequest.responseText);
}
});
getRequest.send();
}
<property> value <property>
Property1: value
Property2: value
etc.
var objectfile = {};
function getfilecontent(url){
var cli = new XMLHttpRequest();
cli.onload = function(){
if((this.status == 200 || this.status == 0) && this.responseText != null) {
var r = this.responseText;
var b=(r.indexOf('\n')?'\n':r.indexOf('\r')?'\r':'');
if(b.length){
if(b=='\n'){var j=r.toString().replace(/\r/gi,'');}else{var j=r.toString().replace(/\n/gi,'');}
r=j.split(b);
r=r.filter(function(val){if( val == '' || val == NaN || val == undefined || val == null ){return false;}return true;});
r = r.map(f => f.trim());
}
if(r.length > 0){
for(var i=0; i<r.length; i++){
var m = r[i].split(':');
if(m.length>1){
var mname = m[0];
var n = m.shift();
var ivalue = m.join(':');
objectfile[mname]=ivalue;
}
}
}
}
}
cli.open("GET", url);
cli.send();
}
getfilecontent('mesite.com/mefile.txt');
window.onload = function(){
if(objectfile !== null){
alert (objectfile.property1.value);
}
}
yournavigator.exe '' --allow-file-access-from-files
// 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()
<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>
fetch('https://www.randomtext.me/api/lorem')