如何使用JavaScript进行AJAX调用,而不使用jQuery?
当前回答
如果您不想包含JQuery,我建议您尝试一些轻量级AJAX库。
我最喜欢的是reqwest。它只有3.4kb,构建得非常好:https://github.com/ded/Reqwest
下面是一个带有reqwest的GET请求示例:
reqwest({
url: url,
method: 'GET',
type: 'json',
success: onSuccess
});
现在,如果您想要更轻量级的东西,我将尝试仅需0.4kb的microAjax: https://code.google.com/p/microajax/
这是所有的代码:
function microAjax(B,A){this.bindFunction=function(E,D){return function(){return E.apply(D,[D])}};this.stateChange=function(D){if(this.request.readyState==4){this.callbackFunction(this.request.responseText)}};this.getRequest=function(){if(window.ActiveXObject){return new ActiveXObject("Microsoft.XMLHTTP")}else{if(window.XMLHttpRequest){return new XMLHttpRequest()}}return false};this.postBody=(arguments[2]||"");this.callbackFunction=A;this.url=B;this.request=this.getRequest();if(this.request){var C=this.request;C.onreadystatechange=this.bindFunction(this.stateChange,this);if(this.postBody!==""){C.open("POST",B,true);C.setRequestHeader("X-Requested-With","XMLHttpRequest");C.setRequestHeader("Content-type","application/x-www-form-urlencoded");C.setRequestHeader("Connection","close")}else{C.open("GET",B,true)}C.send(this.postBody)}};
下面是一个示例调用:
microAjax(url, onSuccess);
其他回答
你可以根据浏览器获得正确的对象
function getXmlDoc() {
var xmlDoc;
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlDoc = new XMLHttpRequest();
}
else {
// code for IE6, IE5
xmlDoc = new ActiveXObject("Microsoft.XMLHTTP");
}
return xmlDoc;
}
有了正确的对象,GET可以被抽象为:
function myGet(url, callback) {
var xmlDoc = getXmlDoc();
xmlDoc.open('GET', url, true);
xmlDoc.onreadystatechange = function() {
if (xmlDoc.readyState === 4 && xmlDoc.status === 200) {
callback(xmlDoc);
}
}
xmlDoc.send();
}
并将邮件发送到:
function myPost(url, data, callback) {
var xmlDoc = getXmlDoc();
xmlDoc.open('POST', url, true);
xmlDoc.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlDoc.onreadystatechange = function() {
if (xmlDoc.readyState === 4 && xmlDoc.status === 200) {
callback(xmlDoc);
}
}
xmlDoc.send(data);
}
老了,但我会尝试,也许有人会发现这个信息有用。
这是执行GET请求并获取一些JSON格式数据所需的最小代码量。这只适用于现代浏览器,如最新版本的Chrome, FF, Safari, Opera和Microsoft Edge。
const xhr = new XMLHttpRequest();
xhr.open('GET', 'https://example.com/data.json'); // by default async
xhr.responseType = 'json'; // in which format you expect the response to be
xhr.onload = function() {
if(this.status == 200) {// onload called even on 404 etc so check the status
console.log(this.response); // No need for JSON.parse()
}
};
xhr.onerror = function() {
// error
};
xhr.send();
还可以查看新的Fetch API,它是XMLHttpRequest API的基于承诺的替代品。
这里有一个非常好的纯javascript解决方案
/*create an XMLHttpRequest object*/
let GethttpRequest=function(){
let httpRequest=false;
if(window.XMLHttpRequest){
httpRequest =new XMLHttpRequest();
if(httpRequest.overrideMimeType){
httpRequest.overrideMimeType('text/xml');
}
}else if(window.ActiveXObject){
try{httpRequest =new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
try{
httpRequest =new ActiveXObject("Microsoft.XMLHTTP");
}catch(e){}
}
}
if(!httpRequest){return 0;}
return httpRequest;
}
/*Defining a function to make the request every time when it is needed*/
function MakeRequest(){
let uriPost ="myURL";
let xhrPost =GethttpRequest();
let fdPost =new FormData();
let date =new Date();
/*data to be sent on server*/
let data = {
"name" :"name",
"lName" :"lName",
"phone" :"phone",
"key" :"key",
"password" :"date"
};
let JSONdata =JSON.stringify(data);
fdPost.append("data",JSONdata);
xhrPost.open("POST" ,uriPost, true);
xhrPost.timeout = 9000;/*the time you need to quit the request if it is not completed*/
xhrPost.onloadstart = function (){
/*do something*/
};
xhrPost.onload = function (){
/*do something*/
};
xhrPost.onloadend = function (){
/*do something*/
}
xhrPost.onprogress =function(){
/*do something*/
}
xhrPost.onreadystatechange =function(){
if(xhrPost.readyState < 4){
}else if(xhrPost.readyState === 4){
if(xhrPost.status === 200){
/*request succesfull*/
}else if(xhrPost.status !==200){
/*request failled*/
}
}
}
xhrPost.ontimeout = function (e){
/*you can stop the request*/
}
xhrPost.onerror = function (){
/*you can try again the request*/
};
xhrPost.onabort = function (){
/*you can try again the request*/
};
xhrPost.overrideMimeType("text/plain; charset=x-user-defined-binary");
xhrPost.setRequestHeader("Content-disposition", "form-data");
xhrPost.setRequestHeader("X-Requested-With","xmlhttprequest");
xhrPost.send(fdPost);
}
/*PHP side
<?php
//check if the variable $_POST["data"] exists isset() && !empty()
$data =$_POST["data"];
$decodedData =json_decode($_POST["data"]);
//show a single item from the form
echo $decodedData->name;
?>
*/
/*Usage*/
MakeRequest();
<html>
<script>
var xmlDoc = null ;
function load() {
if (typeof window.ActiveXObject != 'undefined' ) {
xmlDoc = new ActiveXObject("Microsoft.XMLHTTP");
xmlDoc.onreadystatechange = process ;
}
else {
xmlDoc = new XMLHttpRequest();
xmlDoc.onload = process ;
}
xmlDoc.open( "GET", "background.html", true );
xmlDoc.send( null );
}
function process() {
if ( xmlDoc.readyState != 4 ) return ;
document.getElementById("output").value = xmlDoc.responseText ;
}
function empty() {
document.getElementById("output").value = '<empty>' ;
}
</script>
<body>
<textarea id="output" cols='70' rows='40'><empty></textarea>
<br></br>
<button onclick="load()">Load</button>
<button onclick="empty()">Clear</button>
</body>
</html>
在浏览器中使用纯JavaScript:
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState == XMLHttpRequest.DONE ) {
if(xhr.status == 200){
console.log(xhr.responseText);
} else if(xhr.status == 400) {
console.log('There was an error 400');
} else {
console.log('something else other than 200 was returned');
}
}
}
xhr.open("GET", "mock_data.json", true);
xhr.send();
或者如果你想使用Browserify使用node.js来捆绑你的模块。你可以使用超级代理:
var request = require('superagent');
var url = '/mock_data.json';
request
.get(url)
.end(function(err, res){
if (res.ok) {
console.log('yay got ' + JSON.stringify(res.body));
} else {
console.log('Oh no! error ' + res.text);
}
});