个人学习用途而已，仅供参考。
class Ajax {
constructor(xhr) {
xhr = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XMLHTTP");
this.xhr = xhr;
} send(method, url, async, callback, data) {
let xhr = this.xhr; xhr.onreadystatechange = () => {
// readyState: 0: init, 1: connect has set up, 2: recive request, 3: request.. , 4: request end, send response
if (xhr.readyState === 4 && xhr.status === 200) {
// status: 200: OK, 404: Not Found Page
callback(xhr.responseText);
}
}; xhr.open(method, url, async);
xhr.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xhr.send(data);
}
}
Promise增强版:
class Ajax {
constructor(xhr) {
xhr = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XMLHTTP");
this.xhr = xhr;
} send(options) { let xhr = this.xhr; let opt = {
type: options.type || 'get',
url: options.url || '',
async: options.async || true,
dataType: options.dataType || 'json',
questring: options.questring || ''
}; return new Promise((resolve, reject) => { xhr.open(opt.type, opt.url, opt.async); xhr.onreadystatechange = () => {
// readyState: 0: init, 1: connect has set up, 2: recive request, 3: request.. , 4: request end, send response
if (xhr.readyState === 4) {
if (xhr.status === 200) {
// status: 200: OK, 404: Not Found Page
if (opt.dataType === 'json') {
const data = JSON.parse(xhr.responseText);
resolve(data);
}
} else {
reject(new Error(xhr.status || 'Server is fail.'));
}
}
}; xhr.onerror = () => {
reject(new Error(xhr.status || 'Server is fail.'));
} xhr.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xhr.send(opt.questring); });
}
}
