是否有可能在JavaScript中检测“空闲”时间?
我的主要用例可能是预取或预加载内容。
我将空闲时间定义为用户不活动或没有任何CPU使用的时间段
当前回答
我终于把这个工作在我的网站。我发现equiman的回答最有帮助。这个答案的问题是JavaScript中的alert()函数会暂停脚本执行。如果您像我一样希望发送一个警报，然后如果没有收到响应，站点将自动注销，那么暂停执行是一个问题。
解决方案是用自定义除法替换alert()，如下所述。
下面是代码:(注意:您需要更改第58行以重定向到您的站点的适当URL)
var inactivityTracker = function () { // Create an alert division var alertDiv = document.createElement("div"); alertDiv.setAttribute("style","position: absolute;top: 30%;left: 42.5%;width: 200px;height: 37px;background-color: red;text-align: center; color:white"); alertDiv.innerHTML = "You will be logged out in 5 seconds!!"; // Initialise a variable to store an alert and logout timer var alertTimer; var logoutTimer; // Set the timer thresholds in seconds var alertThreshold = 3; var logoutThreshold = 5; // Start the timer window.onload = resetAlertTimer; // Ensure timer resets when activity logged registerActivityLoggers(resetAlertTimer); // ***** FUNCTIONS ***** // // Function to register activities for alerts function registerActivityLoggers(functionToCall) { document.onmousemove = functionToCall; document.onkeypress = functionToCall; } // Function to reset the alert timer function resetAlertTimer() { clearTimeout(alertTimer); alertTimer = setTimeout(sendAlert, alertThreshold * 1000); } // Function to start logout timer function startLogoutTimer() { clearTimeout(logoutTimer); logoutTimer = setTimeout(logout, logoutThreshold * 1000); } // Function to logout function sendAlert() { // Send a logout alert document.body.appendChild(alertDiv); // Start the logout timer startLogoutTimer(); // Reset everything if an activity is logged registerActivityLoggers(reset); } // Function to logout function logout(){ //location.href = 'index.php'; } // Function to remove alert and reset logout timer function reset(){ // Remove alert division alertDiv.parentNode.removeChild(alertDiv); // Clear the logout timer clearTimeout(logoutTimer); // Restart the alert timer document.onmousemove = resetAlertTimer; document.onkeypress = resetAlertTimer; } }; <html> <script type="text/javascript" src="js/inactivityAlert.js"></script> <head> <title>Testing an inactivity timer</title> </head> <body onload="inactivityTracker();" > Testing an inactivity timer </body> </html>
其他回答
根据equiman提供的输入:
class _Scheduler {
timeoutIDs;
constructor() {
this.timeoutIDs = new Map();
}
addCallback = (callback, timeLapseMS, autoRemove) => {
if (!this.timeoutIDs.has(timeLapseMS + callback)) {
let timeoutID = setTimeout(callback, timeLapseMS);
this.timeoutIDs.set(timeLapseMS + callback, timeoutID);
}
if (autoRemove !== false) {
setTimeout(
this.removeIdleTimeCallback, // Remove
10000 + timeLapseMS, // 10 secs after
callback, // the callback
timeLapseMS, // is invoked.
);
}
};
removeCallback = (callback, timeLapseMS) => {
let timeoutID = this.timeoutIDs.get(timeLapseMS + callback);
if (timeoutID) {
clearTimeout(timeoutID);
this.timeoutIDs.delete(timeLapseMS + callback);
}
};
}
class _IdleTimeScheduler extends _Scheduler {
events = [
'load',
'mousedown',
'mousemove',
'keydown',
'keyup',
'input',
'scroll',
'touchstart',
'touchend',
'touchcancel',
'touchmove',
];
callbacks;
constructor() {
super();
this.events.forEach(name => {
document.addEventListener(name, this.resetTimer, true);
});
this.callbacks = new Map();
}
addIdleTimeCallback = (callback, timeLapseMS) => {
this.addCallback(callback, timeLapseMS, false);
let callbacksArr = this.callbacks.get(timeLapseMS);
if (!callbacksArr) {
this.callbacks.set(timeLapseMS, [callback]);
} else {
if (!callbacksArr.includes(callback)) {
callbacksArr.push(callback);
}
}
};
removeIdleTimeCallback = (callback, timeLapseMS) => {
this.removeCallback(callback, timeLapseMS);
let callbacksArr = this.callbacks.get(timeLapseMS);
if (callbacksArr) {
let index = callbacksArr.indexOf(callback);
if (index !== -1) {
callbacksArr.splice(index, 1);
}
}
};
resetTimer = () => {
for (let [timeLapseMS, callbacksArr] of this.callbacks) {
callbacksArr.forEach(callback => {
// Clear the previous IDs
let timeoutID = this.timeoutIDs.get(timeLapseMS + callback);
clearTimeout(timeoutID);
// Create new timeout IDs.
timeoutID = setTimeout(callback, timeLapseMS);
this.timeoutIDs.set(timeLapseMS + callback, timeoutID);
});
}
};
}
export const Scheduler = new _Scheduler();
export const IdleTimeScheduler = new _IdleTimeScheduler();
你也许可以使用上面列出的鼠标移动技巧来检测网页上的不活跃状态，但这并不能告诉你用户不在另一个窗口或选项卡的另一个页面上，或者用户在Word、Photoshop或WoW中，只是在这个时候没有在看你的页面。
一般来说，我只会预取，并依赖于客户端的多任务处理。如果你真的需要这个功能，你可以在Windows中使用ActiveX控件做一些事情，但它充其量是丑陋的。
Debounce其实是个好主意!下面是一个用于无jquery项目的版本:
const derivedLogout = createDerivedLogout(30);
derivedLogout(); // It could happen that the user is too idle)
window.addEventListener('click', derivedLogout, false);
window.addEventListener('mousemove', derivedLogout, false);
window.addEventListener('keyup', derivedLogout, false);
function createDerivedLogout (sessionTimeoutInMinutes) {
return _.debounce( () => {
window.location = this.logoutUrl;
}, sessionTimeoutInMinutes * 60 * 1000 )
}
我编写了一个小型ES6类来检测活动，并在空闲超时时触发事件。它涵盖了键盘，鼠标和触摸，可以激活和禁用，并且有一个非常精简的API:
const timer = new IdleTimer(() => alert('idle for 1 minute'), 1000 * 60 * 1);
timer.activate();
它不依赖于jQuery，不过您可能需要通过Babel来运行它以支持旧的浏览器。
https://gist.github.com/4547ef5718fd2d31e5cdcafef0208096
下面是tvanfosson的想法的粗略jQuery实现:
$(document).ready(function(){
idleTime = 0;
//Increment the idle time counter every second.
var idleInterval = setInterval(timerIncrement, 1000);
function timerIncrement()
{
idleTime++;
if (idleTime > 2)
{
doPreload();
}
}
//Zero the idle timer on mouse movement.
$(this).mousemove(function(e){
idleTime = 0;
});
function doPreload()
{
//Preload images, etc.
}
})
