如何使用JavaScript进行AJAX调用，而不使用jQuery?
当前回答
var load_process = false;
function ajaxCall(param, response) {
if (load_process == true) {
return;
}
else
{
if (param.async == undefined) {
param.async = true;
}
if (param.async == false) {
load_process = true;
}
var xhr;
xhr = new XMLHttpRequest();
if (param.type != "GET") {
xhr.open(param.type, param.url, true);
if (param.processData != undefined && param.processData == false && param.contentType != undefined && param.contentType == false) {
}
else if (param.contentType != undefined || param.contentType == true) {
xhr.setRequestHeader('Content-Type', param.contentType);
}
else {
xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
}
}
else {
xhr.open(param.type, param.url + "?" + obj_param(param.data));
}
xhr.onprogress = function (loadTime) {
if (param.progress != undefined) {
param.progress({ loaded: loadTime.loaded }, "success");
}
}
xhr.ontimeout = function () {
this.abort();
param.success("timeout", "timeout");
load_process = false;
};
xhr.onerror = function () {
param.error(xhr.responseText, "error");
load_process = false;
};
xhr.onload = function () {
if (xhr.status === 200) {
if (param.dataType != undefined && param.dataType == "json") {
param.success(JSON.parse(xhr.responseText), "success");
}
else {
param.success(JSON.stringify(xhr.responseText), "success");
}
}
else if (xhr.status !== 200) {
param.error(xhr.responseText, "error");
}
load_process = false;
};
if (param.data != null || param.data != undefined) {
if (param.processData != undefined && param.processData == false && param.contentType != undefined && param.contentType == false) {
xhr.send(param.data);
}
else {
xhr.send(obj_param(param.data));
}
}
else {
xhr.send();
}
if (param.timeout != undefined) {
xhr.timeout = param.timeout;
}
else
{
xhr.timeout = 20000;
}
this.abort = function (response) {
if (XMLHttpRequest != null) {
xhr.abort();
load_process = false;
if (response != undefined) {
response({ status: "success" });
}
}
}
}
}
function obj_param(obj) {
var parts = [];
for (var key in obj) {
if (obj.hasOwnProperty(key)) {
parts.push(encodeURIComponent(key) + '=' + encodeURIComponent(obj[key]));
}
}
return parts.join('&');
}
我的ajax调用
var my_ajax_call=ajaxCall({
url: url,
type: method,
data: {data:value},
dataType: 'json',
async:false,//synchronous request. Default value is true
timeout:10000,//default timeout 20000
progress:function(loadTime,status)
{
console.log(loadTime);
},
success: function (result, status) {
console.log(result);
},
error :function(result,status)
{
console.log(result);
}
});
对于中止先前的请求
my_ajax_call.abort(function(result){
console.log(result);
});
其他回答
这个版本在普通ES6/ES2015中怎么样?
function get(url) {
return new Promise((resolve, reject) => {
const req = new XMLHttpRequest();
req.open('GET', url);
req.onload = () => req.status === 200 ? resolve(req.response) : reject(Error(req.statusText));
req.onerror = (e) => reject(Error(`Network Error: ${e}`));
req.send();
});
}
函数返回一个promise。下面是一个关于如何使用该函数并处理它返回的承诺的示例:
get('foo.txt')
.then((data) => {
// Do stuff with data, if foo.txt was successfully loaded.
})
.catch((err) => {
// Do stuff on error...
});
如果你需要加载一个json文件，你可以使用json .parse()将加载的数据转换为JS对象。
您还可以集成req。responseType='json'到函数中，但不幸的是，没有IE支持它，所以我将坚持使用json .parse()。
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
alert(this.responseText);
}
};
xhttp.open("GET", "ajax_info.txt", true);
xhttp.send();
XMLHttpRequest ()
您可以使用XMLHttpRequest()构造函数创建一个新的XMLHttpRequest(XHR)对象，该对象将允许您使用标准的HTTP请求方法(如GET和POST)与服务器交互:
const data = JSON.stringify({
example_1: 123,
example_2: 'Hello, world!',
});
const request = new XMLHttpRequest();
request.addEventListener('load', function () {
if (this.readyState === 4 && this.status === 200) {
console.log(this.responseText);
}
});
request.open('POST', 'example.php', true);
request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
request.send(data);
fetch ()
你也可以使用fetch()方法获取一个Promise，它解析为响应对象，表示对请求的响应:
const data = JSON.stringify({
example_1: 123,
example_2: 'Hello, world!',
});
fetch('example.php', {
method: 'POST',
headers: {
'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
},
body: data,
}).then(response => {
if (response.ok) {
response.text().then(response => {
console.log(response);
});
}
});
领航员sendBeacon()。
另一方面，如果你只是试图POST数据，不需要服务器的响应，最短的解决方案是使用navigator.sendBeacon():
const data = JSON.stringify({
example_1: 123,
example_2: 'Hello, world!',
});
navigator.sendBeacon('example.php', data);
HTML:
<!DOCTYPE html>
<html>
<head>
<script>
function loadXMLDoc()
{
var xmlhttp;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","1.php?id=99freebies.blogspot.com",true);
xmlhttp.send();
}
</script>
</head>
<body>
<div id="myDiv"><h2>Let AJAX change this text</h2></div>
<button type="button" onclick="loadXMLDoc()">Change Content</button>
</body>
</html>
PHP:
<?php
$id = $_GET[id];
print "$id";
?>
使用XMLHttpRequest。
简单的GET请求
httpRequest = new XMLHttpRequest()
httpRequest.open('GET', 'http://www.example.org/some.file')
httpRequest.send()
简单的POST请求
httpRequest = new XMLHttpRequest()
httpRequest.open('POST', 'http://www.example.org/some/endpoint')
httpRequest.send('some data')
我们可以通过可选的第三个参数指定请求应该是异步(true)(默认值)或同步(false)。
// Make a synchronous GET request
httpRequest.open('GET', 'http://www.example.org/some.file', false)
我们可以在调用httpRequest.send()之前设置头信息
httpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
我们可以通过设置httpRequest来处理响应。在调用httpRequest.send()之前，onreadystatechange函数
httpRequest.onreadystatechange = function(){
// Process the server response here.
if (httpRequest.readyState === XMLHttpRequest.DONE) {
if (httpRequest.status === 200) {
alert(httpRequest.responseText);
} else {
alert('There was a problem with the request.');
}
}
}
