如何使用JavaScript进行AJAX调用,而不使用jQuery?


当前回答

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);
     }
 });

其他回答

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);
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);
       });

您可以使用以下函数:

function callAjax(url, callback){
    var xmlhttp;
    // compatible with IE7+, Firefox, Chrome, Opera, Safari
    xmlhttp = new XMLHttpRequest();
    xmlhttp.onreadystatechange = function(){
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200){
            callback(xmlhttp.responseText);
        }
    }
    xmlhttp.open("GET", url, true);
    xmlhttp.send();
}

你可以在这些链接上尝试类似的解决方案:

https://www.w3schools.com/xml/tryit.asp?filename=tryajax_first https://www.w3schools.com/xml/tryit.asp?filename=tryajax_callback

使用“vanilla”(普通)JavaScript:

function loadXMLDoc() {
    var xmlhttp = new XMLHttpRequest();

    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == XMLHttpRequest.DONE) { // XMLHttpRequest.DONE == 4
           if (xmlhttp.status == 200) {
               document.getElementById("myDiv").innerHTML = xmlhttp.responseText;
           }
           else if (xmlhttp.status == 400) {
              alert('There was an error 400');
           }
           else {
               alert('something else other than 200 was returned');
           }
        }
    };

    xmlhttp.open("GET", "ajax_info.txt", true);
    xmlhttp.send();
}

jQuery:

$.ajax({
    url: "test.html",
    context: document.body,
    success: function() {
      $(this).addClass("done");
    }
});

下面的几个例子的一个小组合,创造了这个简单的作品:

function ajax(url, method, data, async)
{
    method = typeof method !== 'undefined' ? method : 'GET';
    async = typeof async !== 'undefined' ? async : false;

    if (window.XMLHttpRequest)
    {
        var xhReq = new XMLHttpRequest();
    }
    else
    {
        var xhReq = new ActiveXObject("Microsoft.XMLHTTP");
    }


    if (method == 'POST')
    {
        xhReq.open(method, url, async);
        xhReq.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        xhReq.setRequestHeader("X-Requested-With", "XMLHttpRequest");
        xhReq.send(data);
    }
    else
    {
        if(typeof data !== 'undefined' && data !== null)
        {
            url = url+'?'+data;
        }
        xhReq.open(method, url, async);
        xhReq.setRequestHeader("X-Requested-With", "XMLHttpRequest");
        xhReq.send(null);
    }
    //var serverResponse = xhReq.responseText;
    //alert(serverResponse);
}

// Example usage below (using a string query):

ajax('http://www.google.com');
ajax('http://www.google.com', 'POST', 'q=test');

或者如果你的参数是object(s) -轻微的额外代码调整:

var parameters = {
    q: 'test'
}

var query = [];
for (var key in parameters)
{
    query.push(encodeURIComponent(key) + '=' + encodeURIComponent(parameters[key]));
}

ajax('http://www.google.com', 'POST', query.join('&'));

两者都应该完全兼容浏览器+版本。