How to implement AJAX and JSONP in native JS
I believe there are always some friends who don’t like to use plug-ins when writing code and prefer to use native JS to write. So today I will bring you a tutorial to use native JavaScript to implement AJAX and JSONP.
function ajax(params) {
params = params || {};
params.data = params.data || {};
// 判断是ajax请求还是jsonp请求
var json = params.jsonp ? jsonp(params) : json(params);
// ajax请求
function json(params) {
params.type = (params.type || 'GET').toUpperCase(); // 请求方式，默认是GET
params.data = formatParams(params.data); // 避免有特殊字符，必须格式化传输数据
var xhr = null;
// 实例化XMLHttpRequest对象
if(window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
} else {
// IE6及其以下版本
xhr = new ActiveXObjcet('Microsoft.XMLHTTP');
};
// 监听事件，只要 readyState 的值变化，就会调用 readystatechange 事件
xhr.onreadystatechange = function() {
// readyState属性表示请求/响应过程的当前活动阶段，4为完成，已经接收到全部响应数据
if(xhr.readyState == 4) {
var status = xhr.status;
// status：响应的HTTP状态码，以2开头的都是成功
if(status >= 200 && status < 300) {
var response = '';
// 判断接受数据的内容类型
var type = xhr.getResponseHeader('Content-type');
if(type.indexOf('xml') !== -1 && xhr.responseXML) {
response = xhr.responseXML; //Document对象响应
} else if(type === 'application/json') {
response = JSON.parse(xhr.responseText); //JSON响应
} else {
response = xhr.responseText; //字符串响应
};
// 成功回调函数
params.success && params.success(response);
} else {
params.error && params.error(status);
}
};
};
// 连接和传输数据
if(params.type == 'GET') {
// 三个参数：请求方式、请求地址(get方式时，传输数据是加在地址后的)、是否异步请求(同步请求的情况极少)；
xhr.open(params.type, params.url + '?' + params.data, true);
xhr.send(null);
} else {
xhr.open(params.type, params.url, true);
//必须，设置提交时的内容类型
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
// 传输数据
xhr.send(params.data);
}
}
//格式化参数
function formatParams(data) {
var arr = [];
for(var name in data) {
// encodeURIComponent() ：用于对 URI 中的某一部分进行编码
arr.push(encodeURIComponent(name) + '=' + encodeURIComponent(data[name]));
};
// 添加一个随机数参数，防止缓存
arr.push('v=' + random());
return arr.join('&');
}
// 获取随机数
function random() {
return Math.floor(Math.random() * 10000 + 500);
}
}I believe you have mastered the methods after reading these cases. For more exciting information, please pay attention to other related articles on the php Chinese website!
Related reading:
Summary of the front-end js framework and explanation of its uses
Detailed introduction to the three major structures of the javascript development tutorial
How to implement Web Worker with multi-threading in H5
The above is the detailed content of How to implement AJAX and JSONP in native JS. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1377
52
How to solve the 403 error encountered by jQuery AJAX request
Feb 20, 2024 am 10:07 AM
Title: Methods and code examples to resolve 403 errors in jQuery AJAX requests. The 403 error refers to a request that the server prohibits access to a resource. This error usually occurs because the request lacks permissions or is rejected by the server. When making jQueryAJAX requests, you sometimes encounter this situation. This article will introduce how to solve this problem and provide code examples. Solution: Check permissions: First ensure that the requested URL address is correct and verify that you have sufficient permissions to access the resource.
How to solve jQuery AJAX request 403 error
Feb 19, 2024 pm 05:55 PM
jQuery is a popular JavaScript library used to simplify client-side development. AJAX is a technology that sends asynchronous requests and interacts with the server without reloading the entire web page. However, when using jQuery to make AJAX requests, you sometimes encounter 403 errors. 403 errors are usually server-denied access errors, possibly due to security policy or permission issues. In this article, we will discuss how to resolve jQueryAJAX request encountering 403 error
How to get variables from PHP method using Ajax?
Mar 09, 2024 pm 05:36 PM
Using Ajax to obtain variables from PHP methods is a common scenario in web development. Through Ajax, the page can be dynamically obtained without refreshing the data. In this article, we will introduce how to use Ajax to get variables from PHP methods, and provide specific code examples. First, we need to write a PHP file to handle the Ajax request and return the required variables. Here is sample code for a simple PHP file getData.php:
How to solve the problem of jQuery AJAX error 403?
Feb 23, 2024 pm 04:27 PM
How to solve the problem of jQueryAJAX error 403? When developing web applications, jQuery is often used to send asynchronous requests. However, sometimes you may encounter error code 403 when using jQueryAJAX, indicating that access is forbidden by the server. This is usually caused by server-side security settings, but there are ways to work around it. This article will introduce how to solve the problem of jQueryAJAX error 403 and provide specific code examples. 1. to make
PHP and Ajax: Building an autocomplete suggestion engine
Jun 02, 2024 pm 08:39 PM
Build an autocomplete suggestion engine using PHP and Ajax: Server-side script: handles Ajax requests and returns suggestions (autocomplete.php). Client script: Send Ajax request and display suggestions (autocomplete.js). Practical case: Include script in HTML page and specify search-input element identifier.
PHP vs. Ajax: Solutions for creating dynamically loaded content
Jun 06, 2024 pm 01:12 PM
Ajax (Asynchronous JavaScript and XML) allows adding dynamic content without reloading the page. Using PHP and Ajax, you can dynamically load a product list: HTML creates a page with a container element, and the Ajax request adds the data to that element after loading it. JavaScript uses Ajax to send a request to the server through XMLHttpRequest to obtain product data in JSON format from the server. PHP uses MySQL to query product data from the database and encode it into JSON format. JavaScript parses the JSON data and displays it in the page container. Clicking the button triggers an Ajax request to load the product list.
PHP and Ajax: Ways to Improve Ajax Security
Jun 01, 2024 am 09:34 AM
In order to improve Ajax security, there are several methods: CSRF protection: generate a token and send it to the client, add it to the server side in the request for verification. XSS protection: Use htmlspecialchars() to filter input to prevent malicious script injection. Content-Security-Policy header: Restrict the loading of malicious resources and specify the sources from which scripts and style sheets are allowed to be loaded. Validate server-side input: Validate input received from Ajax requests to prevent attackers from exploiting input vulnerabilities. Use secure Ajax libraries: Take advantage of automatic CSRF protection modules provided by libraries such as jQuery.
Asynchronous data exchange using Ajax functions
Jan 26, 2024 am 09:41 AM
How to use Ajax functions to achieve asynchronous data interaction With the development of the Internet and Web technology, data interaction between the front end and the back end has become very important. Traditional data interaction methods, such as page refresh and form submission, can no longer meet user needs. Ajax (Asynchronous JavaScript and XML) has become an important tool for asynchronous data interaction. Ajax enables the web to use JavaScript and the XMLHttpRequest object
