问题
I have a jquery script in my shared _Layout.cshtml, which records the last click and logs out the user after a specific time interval. The problem that arises is that when more than 1 pages are opend (i.e, in multiple tabs of browser, different pages of same application are opened), if any page remains idle for specified time, it logs out the user. and the other page that the user is currently working on, when user clicks, it throws exception (which is obvious, because user has been logged out by other page). I cannot use sessions related stuff. is there anyway, i can maintain scope of such type of variables across different opened tabs of browser? I want to reset the timer of other opened tabs to zero, if user is working on any of the opened tabs. I tried to look around for the answer first, but i found every issue different as compared to my scenario.
(I'm using MVC 4. Jquery script is in /Shared/_Layout.cshtml)
回答1:
I solved it using some library, called store.js. It doesn't require polling server and stuff, instead, a cookie is simply shared instantly across the tabs, very soon as it is set on any of the opened tabs (without the need for tab to refresh; which normally is required in order to get cookie, set on some other tab.). and above all, what i loved about this is that store.js uses localStorage when available, and falls back on the userData behavior in IE6 and IE7. No flash to slow down your page load. No cookies to fatten your network requests. store.js depends on JSON for serialization to disk. It's very simple to use.
Example use:
store.set('username', 'joe')
document.write('username: ' + store.get('username') + '<br />')
store.remove('username')
store.clear()
store.set('user', { name: 'joe', likes: 'javascript' })
var user = store.get('user')
document.write(user.name + ' likes ' + user.likes)
回答2:
The idle timer can communicate (stay in sync) across multiple windows & tabs using localStorage. On github, marcuswestin/store.js provides good functionality with multiple browser varieties. Here is the 'testing' code for an idletimer plugin which provides synchronized windows/tabs/iframes, provided they are all within the same domain. https://github.com/JillElaine/jquery-idleTimeout
/**
* This work is licensed under the MIT License
*
* Configurable idle (no activity) timer and logout redirect for jQuery.
* Works across multiple windows, tabs and iframes from the same domain.
*
* Dependencies: JQuery v1.7+, JQuery UI, store.js from https://github.com/marcuswestin/store.js - v1.3.4+
*
* Commented and console logged for debugging with Firefox & Firebug or similar
* version 1.0.6
**/
/*global jQuery: false, document: false, store: false, clearInterval: false, setInterval: false, setTimeout: false, window: false, alert: false, console: false*/
/*jslint indent: 2, sloppy: true, plusplus: true*/
(function ($) {
$.fn.idleTimeout = function (options) {
console.log('start');
//##############################
//## Configuration Variables
//##############################
var defaults = {
idleTimeLimit: 30000, // 30 seconds for testing. 'No activity' time limit in milliseconds. 1200000 = 20 Minutes
dialogDisplayLimit: 20000, // 20 seconds for testing. Time to display the warning dialog before redirect (and optional callback) in milliseconds. 180000 = 3 Minutes
redirectUrl: '/logout', // redirect to this url on timeout logout. Set to "redirectUrl: false" to disable redirect
// optional custom callback to perform before redirect
customCallback: false, // set to false for no customCallback
// customCallback: function () { // define optional custom js function
// perform custom action before logout
// },
// configure which activity events to detect
// http://www.quirksmode.org/dom/events/
// https://developer.mozilla.org/en-US/docs/Web/Reference/Events
activityEvents: 'click keypress scroll wheel mousewheel', // separate each event with a space
//dialog box configuration
dialogTitle: 'Session Expiration Warning',
dialogText: 'Because you have been inactive, your session is about to expire.',
// server-side session keep-alive timer
sessionKeepAliveTimer: 600000 // Ping the server at this interval in milliseconds. 600000 = 10 Minutes
// sessionKeepAliveTimer: false // Set to false to disable pings
},
//##############################
//## Private Variables
//##############################
opts = $.extend(defaults, options),
checkHeartbeat = 2000, // frequency to check for timeouts - 2000 = 2 seconds
origTitle = document.title, // save original browser title
sessionKeepAliveUrl = window.location.href, // set URL to ping to user's current window
keepSessionAlive, activityDetector,
idleTimer, remainingTimer, checkIdleTimeout, idleTimerLastActivity, startIdleTimer, stopIdleTimer,
openWarningDialog, dialogTimer, checkDialogTimeout, startDialogTimer, stopDialogTimer, isDialogOpen, destroyWarningDialog,
countdownDisplay, logoutUser,
checkForIframes, includeIframes, attachEventIframe; // iframe functionality
//##############################
//## Private Functions
//##############################
keepSessionAlive = function () {
if (opts.sessionKeepAliveTimer) {
var keepSession = function () {
if (idleTimerLastActivity === store.get('idleTimerLastActivity')) {
console.log('keep session alive function');
$.get(sessionKeepAliveUrl);
}
};
setInterval(keepSession, opts.sessionKeepAliveTimer);
}
};
activityDetector = function () {
$('body').on(opts.activityEvents, function () {
if (isDialogOpen() !== true) {
console.log('activity detected');
startIdleTimer();
} else {
console.log('dialog open. activity ignored');
}
});
};
checkIdleTimeout = function () {
var timeNow = $.now(), timeIdleTimeout = (store.get('idleTimerLastActivity') + opts.idleTimeLimit);
if (timeNow > timeIdleTimeout) {
console.log('timeNow: ' + timeNow + ' > idle ' + timeIdleTimeout);
if (isDialogOpen() !== true) {
console.log('dialog is not open & will be opened');
openWarningDialog();
startDialogTimer();
}
} else if (store.get('idleTimerLoggedOut') === true) { //a 'manual' user logout?
logoutUser();
} else {
console.log('idle not yet timed out');
if (isDialogOpen() === true) {
console.log('dialog is open & will be closed');
destroyWarningDialog();
stopDialogTimer();
}
}
};
startIdleTimer = function () {
stopIdleTimer();
idleTimerLastActivity = $.now();
store.set('idleTimerLastActivity', idleTimerLastActivity);
console.log('start idle timer: ' + idleTimerLastActivity);
idleTimer = setInterval(checkIdleTimeout, checkHeartbeat);
};
stopIdleTimer = function () {
clearInterval(idleTimer);
};
openWarningDialog = function () {
var dialogContent = "<div id='idletimer_warning_dialog'><p>" + opts.dialogText + "</p><p style='display:inline'>Time remaining: <div style='display:inline' id='countdownDisplay'></div></p></div>";
$(dialogContent).dialog({
buttons: {
"Stay Logged In": function () {
console.log('Stay Logged In button clicked');
destroyWarningDialog();
stopDialogTimer();
startIdleTimer();
},
"Log Out Now": function () {
console.log('Log Out Now button clicked');
logoutUser();
}
},
closeOnEscape: false,
modal: true,
title: opts.dialogTitle
});
// hide the dialog's upper right corner "x" close button
$('.ui-dialog-titlebar-close').css('display', 'none');
// start the countdown display
countdownDisplay();
// change title bar to warning message
document.title = opts.dialogTitle;
};
checkDialogTimeout = function () {
var timeNow = $.now(), timeDialogTimeout = (store.get('idleTimerLastActivity') + opts.idleTimeLimit + opts.dialogDisplayLimit);
if ((timeNow > timeDialogTimeout) || (store.get('idleTimerLoggedOut') === true)) {
console.log('timeNow: ' + timeNow + ' > dialog' + timeDialogTimeout);
logoutUser();
} else {
console.log('dialog not yet timed out');
}
};
startDialogTimer = function () {
dialogTimer = setInterval(checkDialogTimeout, checkHeartbeat);
};
stopDialogTimer = function () {
clearInterval(dialogTimer);
clearInterval(remainingTimer);
};
isDialogOpen = function () {
var dialogOpen = $("#idletimer_warning_dialog").is(":visible");
if (dialogOpen === true) {
return true;
}
return false;
};
destroyWarningDialog = function () {
console.log('dialog destroyed');
$(".ui-dialog-content").dialog('destroy').remove();
document.title = origTitle;
};
// display remaining time on warning dialog
countdownDisplay = function () {
var dialogDisplaySeconds = opts.dialogDisplayLimit / 1000, mins, secs;
remainingTimer = setInterval(function () {
mins = Math.floor(dialogDisplaySeconds / 60); // minutes
if (mins < 10) { mins = '0' + mins; }
secs = dialogDisplaySeconds - (mins * 60); // seconds
if (secs < 10) { secs = '0' + secs; }
$('#countdownDisplay').html(mins + ':' + secs);
dialogDisplaySeconds -= 1;
}, 1000);
};
logoutUser = function () {
console.log('logout function');
store.set('idleTimerLoggedOut', true);
if (opts.customCallback) {
console.log('logout function custom callback');
opts.customCallback();
}
if (opts.redirectUrl) {
console.log('logout function redirect to URL');
window.location.href = opts.redirectUrl;
}
};
// document must be in readyState 'complete' before looking for iframes
checkForIframes = function () {
var docReadyCheck, isDocReady;
docReadyCheck = function () {
if (document.readyState === "complete") {
console.log('check for iframes, now that the document is complete');
clearInterval(isDocReady);
includeIframes();
}
};
isDocReady = setInterval(docReadyCheck, 1000);
};
// look for iframes
includeIframes = function () {
console.log('include iframes start');
var foundIframes = document.getElementsByTagName('iframe'), index, iframeItem;
if (foundIframes.length > 0) { //at least one iframe found
console.log('iframes found: ' + foundIframes.length);
// attach events to each iframe found
for (index = 0; index < foundIframes.length; index++) {
iframeItem = foundIframes.item(index);
if (iframeItem.attachEvent) { // IE < 11. Returns a boolean true/false
console.log('attach event to iframe. Browser IE < 11');
iframeItem.attachEvent('onload', attachEventIframe(index));
} else { // IE >= 11 and FF, etc.
console.log('attach event to iframe. Browser NOT IE < 11');
iframeItem.addEventListener('load', attachEventIframe(index), false);
}
} // end for loop
} // end if any iframes
};
// attach events to each iframe
attachEventIframe = function (index) {
var iframe = $('iframe:eq(' + index + ')').contents().find('html');
iframe.on(opts.activityEvents, function (event) {
console.log('bubbling iframe activity event to body of page');
$('body').trigger(event);
});
};
//###############################
// Build & Return the instance of the item as a plugin
// This is your construct.
//###############################
return this.each(function () {
if (store.enabled) {
idleTimerLastActivity = $.now();
store.set('idleTimerLastActivity', idleTimerLastActivity);
store.set('idleTimerLoggedOut', false);
} else {
alert('Please disable "Private Mode", or upgrade to a modern browser. Or perhaps a dependent file missing. Please see: https://github.com/marcuswestin/store.js');
}
activityDetector();
keepSessionAlive();
startIdleTimer();
checkForIframes();
});
};
}(jQuery));
来源：https://stackoverflow.com/questions/23926873/client-side-script-variables-scope-for-multiple-opened-tabs-of-browser-issue