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Reload page after click OK on the Alert Page

I want to reload page after clicking OK button on the javascript Alert box.
Here is my code :
$(".erase").click(function () {
var answer = confirm("Delete This Data?");
if (answer === true) {
var erase = false;
if (!erase) {
erase = true;
$.post('delete.php', {id: $(this).attr('data-id')} );
erase = false;
}
window.location.reload();
} else {
return false;
}
});
if I put the window.location.reload(); there, the page reloading after click OK, but I can't delete the data I want.
If I remove it, I can delete the data but the page doesn't reload.
Please help me on this

You just need to provide the window.reload() as a callback to $.post.
$(".erase").click(function () {
var answer = confirm("Delete This Data?");
if (answer === true) {
var erase = false;
if (!erase) {
erase = true;
$.post('delete.php', {id: $(this).attr('data-id')}, function() { // here's the new bit
window.location.reload();
} );
erase = false;
}
} else {
return false;
}
});

Change your first line to (I write code from head):
$(".erase").click(async function () {
and line with $.post to this:
let postResult = await Promise.resolve($.post('delete.php', {id: $(this).attr('data-id')} ));

how to set event listener to back button in IE?

I need to set an event listener that will listen to the back button in the browser. I need to show alert after the user clicks on the back button.

Thanks for negative response.. its my first question :\
i found this solution and its very useful >>
<SCRIPT type="text/javascript">
window.onload = function ()
{
if (typeof history.pushState === "function")
{
history.pushState("jibberish", null, null);
window.onpopstate = function ()
{
history.pushState('newjibberish', null, null);
// Handle the back (or forward) buttons here
// Will NOT handle refresh, use onbeforeunload for this.
};
}
else
{
var ignoreHashChange = true;
window.onhashchange = function ()
{
if (!ignoreHashChange)
{
ignoreHashChange = true;
window.location.hash = Math.random();
// Detect and redirect change here
// Works in older FF and IE9
// * it does mess with your hash symbol (anchor?) pound sign
// delimiter on the end of the URL
}
else
{
ignoreHashChange = false;
}
};
}
}
</SCRIPT>

Show a div only once per visit / set cookie

I'm trying to set an element so it's being shown only once per visit. It's a scroll down arrow on my homepage and so once the user gets it it won't be necessary to keep it anymore. So I don't want it to be shown while the user is surfing on my website however, when he visits it again in the future it's there again. I'm a newbie and can't quite solve it.
My code:
setTimeout(function () {
$('.scroll_down').show()
}, 2000);
var $element = $('.scroll_down'); // fade out / in on scroll
$(window).scroll(function() {
if($(this).scrollTop() > 0) {
$element.fadeOut(1000);
}
});
I also would like the arrow to fade in but my attempts were not successful. Thanks guys

Please write cookie code as follow:
jQuery(document).ready(function($){
if($.cookie('show_div_once') != 'yes'){
your_code_for_show_div;
}
$.cookie('show_div_once', 'yes', { path: '/', expires: 365 });
});

I used localStorage
firstSiteLoad = (function() {
var checkSupport;
checkSupport = function() {
var e, error, support;
try {
support = 'localStorage' in window && (window['localStorage'] != null);
} catch (error) {
e = error;
support = false;
}
return support;
};
return function() {
if (!checkSupport()) {
return false;
}
if (localStorage.getItem("not_first_load")) {
return false;
} else {
localStorage.setItem("not_first_load", 'true');
return true;
}
};
})();
you can use it by if (firstSiteLoad()) { //your code }

Check if my website is open in another tab

I want to check with JavaScript if the user has already opened my website in another tab in their browser.
It seems I cannot do that with pagevisibility...
The only way I see is to use WebSocket based on a session cookie, and check if the client has more than one socket. But by this way, from current tab, I have to ask my server if this user has a tab opened right next to their current browser tab. It is a little far-fetched!
Maybe with localstorage?

The shorter version with localStorage and Storage listener
<script type="text/javascript">
// Broadcast that you're opening a page.
localStorage.openpages = Date.now();
var onLocalStorageEvent = function(e){
if(e.key == "openpages"){
// Listen if anybody else is opening the same page!
localStorage.page_available = Date.now();
}
if(e.key == "page_available"){
alert("One more page already open");
}
};
window.addEventListener('storage', onLocalStorageEvent, false);
</script>
Update:
Works on page crash as well.
Stimulate page crash in chrome: chrome://inducebrowsercrashforrealz
Live demo

Using local storage I created a simple demo that should accomplish what your looking to do. Basically, it simply maintains a count of currently opened windows. When the window is closed the unload events fire and remove it from the total window count.
When you first look at it, you may think there's more going on than there really is. Most of it was a shotty attempt to add logic into who was the "main" window, and who should take over as the "main" window as you closed children. (Hence the setTimeout calls to recheck if it should be promoted to a main window) After some head scratching, I decided it would take too much time to implement and was outside the scope of this question. However, if you have two windows open (Main, and Child) and you close the Main, the child will be promoted to a main.
For the most part you should be able to get the general idea of whats going on and use it for your own implementation.
See it all in action here:
http://jsbin.com/mipanuro/1/edit
Oh yeah, to actually see it in action... Open the link in multiple windows. :)
Update:
I've made the necessary changes to have the the local storage maintain the "main" window. As you close tabs child windows can then become promoted to a main window. There are two ways to control the "main" window state through a parameter passed to the constructor of WindowStateManager. This implementation is much nicer than my previous attempt.
JavaScript:
// noprotect
var statusWindow = document.getElementById('status');
(function (win)
{
//Private variables
var _LOCALSTORAGE_KEY = 'WINDOW_VALIDATION';
var RECHECK_WINDOW_DELAY_MS = 100;
var _initialized = false;
var _isMainWindow = false;
var _unloaded = false;
var _windowArray;
var _windowId;
var _isNewWindowPromotedToMain = false;
var _onWindowUpdated;
function WindowStateManager(isNewWindowPromotedToMain, onWindowUpdated)
{
//this.resetWindows();
_onWindowUpdated = onWindowUpdated;
_isNewWindowPromotedToMain = isNewWindowPromotedToMain;
_windowId = Date.now().toString();
bindUnload();
determineWindowState.call(this);
_initialized = true;
_onWindowUpdated.call(this);
}
//Determine the state of the window
//If its a main or child window
function determineWindowState()
{
var self = this;
var _previousState = _isMainWindow;
_windowArray = localStorage.getItem(_LOCALSTORAGE_KEY);
if (_windowArray === null || _windowArray === "NaN")
{
_windowArray = [];
}
else
{
_windowArray = JSON.parse(_windowArray);
}
if (_initialized)
{
//Determine if this window should be promoted
if (_windowArray.length <= 1 ||
(_isNewWindowPromotedToMain ? _windowArray[_windowArray.length - 1] : _windowArray[0]) === _windowId)
{
_isMainWindow = true;
}
else
{
_isMainWindow = false;
}
}
else
{
if (_windowArray.length === 0)
{
_isMainWindow = true;
_windowArray[0] = _windowId;
localStorage.setItem(_LOCALSTORAGE_KEY, JSON.stringify(_windowArray));
}
else
{
_isMainWindow = false;
_windowArray.push(_windowId);
localStorage.setItem(_LOCALSTORAGE_KEY, JSON.stringify(_windowArray));
}
}
//If the window state has been updated invoke callback
if (_previousState !== _isMainWindow)
{
_onWindowUpdated.call(this);
}
//Perform a recheck of the window on a delay
setTimeout(function()
{
determineWindowState.call(self);
}, RECHECK_WINDOW_DELAY_MS);
}
//Remove the window from the global count
function removeWindow()
{
var __windowArray = JSON.parse(localStorage.getItem(_LOCALSTORAGE_KEY));
for (var i = 0, length = __windowArray.length; i < length; i++)
{
if (__windowArray[i] === _windowId)
{
__windowArray.splice(i, 1);
break;
}
}
//Update the local storage with the new array
localStorage.setItem(_LOCALSTORAGE_KEY, JSON.stringify(__windowArray));
}
//Bind unloading events
function bindUnload()
{
win.addEventListener('beforeunload', function ()
{
if (!_unloaded)
{
removeWindow();
}
});
win.addEventListener('unload', function ()
{
if (!_unloaded)
{
removeWindow();
}
});
}
WindowStateManager.prototype.isMainWindow = function ()
{
return _isMainWindow;
};
WindowStateManager.prototype.resetWindows = function ()
{
localStorage.removeItem(_LOCALSTORAGE_KEY);
};
win.WindowStateManager = WindowStateManager;
})(window);
var WindowStateManager = new WindowStateManager(false, windowUpdated);
function windowUpdated()
{
//"this" is a reference to the WindowStateManager
statusWindow.className = (this.isMainWindow() ? 'main' : 'child');
}
//Resets the count in case something goes wrong in code
//WindowStateManager.resetWindows()
HTML:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS Bin</title>
</head>
<body>
<div id='status'>
<span class='mainWindow'>Main Window</span>
<span class='childWindow'>Child Window</span>
</div>
</body>
</html>
CSS:
#status
{
display:table;
width:100%;
height:500px;
border:1px solid black;
}
span
{
vertical-align:middle;
text-align:center;
margin:0 auto;
font-size:50px;
font-family:arial;
color:#ba3fa3;
display:none;
}
#status.main .mainWindow,
#status.child .childWindow
{
display:table-cell;
}
.mainWindow
{
background-color:#22d86e;
}
.childWindow
{
background-color:#70aeff;
}

(2021) You can use BroadcastChannel to communicate between tabs of the same origin.
For example, put the following at the top level of your js code, then test by opening 2 tabs:
const bc = new BroadcastChannel("my-awesome-site");
bc.onmessage = (event) => {
if (event.data === `Am I the first?`) {
bc.postMessage(`No you're not.`);
alert(`Another tab of this site just got opened`);
}
if (event.data === `No you're not.`) {
alert(`An instance of this site is already running`);
}
};
bc.postMessage(`Am I the first?`);

I know it is late, but maybe help someone
This snippet of code, will detect how many tabs are open and how many are active (visible) and if none of tabs is active, it will choose last opened tab, as active one.
This code will handle windows/tab crash too and it will refresh the count at crash.
Because localStorage is not supported on Stack Overflow currently, please test here.
<html>
<body>
Open in several tabs or windows
<div id="holder_element"></div>
<script type="text/javascript">
//localStorage.clear();
manage_crash();
//Create a windows ID for each windows that is oppened
var current_window_id = Date.now() + "";//convert to string
var time_period = 3000;//ms
//Check to see if PageVisibility API is supported or not
var PV_API = page_visibility_API_check();
/************************
** PAGE VISIBILITY API **
*************************/
function page_visibility_API_check ()
{
var page_visibility_API = false;
var visibility_change_handler = false;
if ('hidden' in document)
{
page_visibility_API = 'hidden';
visibility_change_handler = 'visibilitychange';
}
else
{
var prefixes = ['webkit','moz','ms','o'];
//loop over all the known prefixes
for (var i = 0; i < prefixes.length; i++){
if ((prefixes[i] + 'Hidden') in document)
{
page_visibility_API = prefixes[i] + 'Hidden';
visibility_change_handler = prefixes[i] + 'visibilitychange';
}
}
}
if (!page_visibility_API)
{
//PageVisibility API is not supported in this device
return page_visibility_API;
}
return {"hidden": page_visibility_API, "handler": visibility_change_handler};
}
if (PV_API)
{
document.addEventListener(PV_API.handler, function(){
//console.log("current_window_id", current_window_id, "document[PV_API.hidden]", document[PV_API.hidden]);
if (document[PV_API.hidden])
{
//windows is hidden now
remove_from_active_windows(current_window_id);
//skip_once = true;
}
else
{
//windows is visible now
//add_to_active_windows(current_window_id);
//skip_once = false;
check_current_window_status ();
}
}, false);
}
/********************************************
** ADD CURRENT WINDOW TO main_windows LIST **
*********************************************/
add_to_main_windows_list(current_window_id);
//update active_window to current window
localStorage.active_window = current_window_id;
/**************************************************************************
** REMOVE CURRENT WINDOWS FROM THE main_windows LIST ON CLOSE OR REFRESH **
***************************************************************************/
window.addEventListener('beforeunload', function ()
{
remove_from_main_windows_list(current_window_id);
});
/*****************************
** ADD TO main_windows LIST **
******************************/
function add_to_main_windows_list(window_id)
{
var temp_main_windows_list = get_main_windows_list();
var index = temp_main_windows_list.indexOf(window_id);
if (index < 0)
{
//this windows is not in the list currently
temp_main_windows_list.push(window_id);
}
localStorage.main_windows = temp_main_windows_list.join(",");
return temp_main_windows_list;
}
/**************************
** GET main_windows LIST **
***************************/
function get_main_windows_list()
{
var temp_main_windows_list = [];
if (localStorage.main_windows)
{
temp_main_windows_list = (localStorage.main_windows).split(",");
}
return temp_main_windows_list;
}
/**********************************************
** REMOVE WINDOWS FROM THE main_windows LIST **
***********************************************/
function remove_from_main_windows_list(window_id)
{
var temp_main_windows_list = [];
if (localStorage.main_windows)
{
temp_main_windows_list = (localStorage.main_windows).split(",");
}
var index = temp_main_windows_list.indexOf(window_id);
if (index > -1) {
temp_main_windows_list.splice(index, 1);
}
localStorage.main_windows = temp_main_windows_list.join(",");
//remove from active windows too
remove_from_active_windows(window_id);
return temp_main_windows_list;
}
/**************************
** GET active_windows LIST **
***************************/
function get_active_windows_list()
{
var temp_active_windows_list = [];
if (localStorage.actived_windows)
{
temp_active_windows_list = (localStorage.actived_windows).split(",");
}
return temp_active_windows_list;
}
/*************************************
** REMOVE FROM actived_windows LIST **
**************************************/
function remove_from_active_windows(window_id)
{
var temp_active_windows_list = get_active_windows_list();
var index = temp_active_windows_list.indexOf(window_id);
if (index > -1) {
temp_active_windows_list.splice(index, 1);
}
localStorage.actived_windows = temp_active_windows_list.join(",");
return temp_active_windows_list;
}
/********************************
** ADD TO actived_windows LIST **
*********************************/
function add_to_active_windows(window_id)
{
var temp_active_windows_list = get_active_windows_list();
var index = temp_active_windows_list.indexOf(window_id);
if (index < 0)
{
//this windows is not in active list currently
temp_active_windows_list.push(window_id);
}
localStorage.actived_windows = temp_active_windows_list.join(",");
return temp_active_windows_list;
}
/*****************
** MANAGE CRASH **
******************/
//If the last update didn't happened recently (more than time_period*2)
//we will clear saved localStorage's data and reload the page
function manage_crash()
{
if (localStorage.last_update)
{
if (parseInt(localStorage.last_update) + (time_period * 2) < Date.now())
{
//seems a crash came! who knows!?
//localStorage.clear();
localStorage.removeItem('main_windows');
localStorage.removeItem('actived_windows');
localStorage.removeItem('active_window');
localStorage.removeItem('last_update');
location.reload();
}
}
}
/********************************
** CHECK CURRENT WINDOW STATUS **
*********************************/
function check_current_window_status(test)
{
manage_crash();
if (PV_API)
{
var active_status = "Inactive";
var windows_list = get_main_windows_list();
var active_windows_list = get_active_windows_list();
if (windows_list.indexOf(localStorage.active_window) < 0)
{
//last actived windows is not alive anymore!
//remove_from_main_windows_list(localStorage.active_window);
//set the last added window, as active_window
localStorage.active_window = windows_list[windows_list.length - 1];
}
if (! document[PV_API.hidden])
{
//Window's page is visible
localStorage.active_window = current_window_id;
}
if (localStorage.active_window == current_window_id)
{
active_status = "Active";
}
if (active_status == "Active")
{
active_windows_list = add_to_active_windows(current_window_id);
}
else
{
active_windows_list = remove_from_active_windows(current_window_id);
}
console.log(test, active_windows_list);
var element_holder = document.getElementById("holder_element");
element_holder.insertAdjacentHTML("afterbegin", "<div>"+element_holder.childElementCount+") Current Windows is "+ active_status +" "+active_windows_list.length+" window(s) is visible and active of "+ windows_list.length +" windows</div>");
}
else
{
console.log("PageVisibility API is not supported :(");
//our INACTIVE pages, will remain INACTIVE forever, you need to make some action in this case!
}
localStorage.last_update = Date.now();
}
//check storage continuously
setInterval(function(){
check_current_window_status ();
}, time_period);
//initial check
check_current_window_status ();
</script>
</body>
</html>

setInterval with other jQuery events - Too many recursions

I'm trying to build a Javascript listener for a small page that uses AJAX to load content based on the anchor in the URL. Looking online, I found and modified a script that uses setInterval() to do this and so far it works fine. However, I have other jQuery elements in the $(document).ready() for special effects for the menus and content. If I use setInterval() no other jQuery effects work. I finagled a way to get it work by including the jQuery effects in the loop for setInterval() like so:
$(document).ready(function() {
var pageScripts = function() {
pageEffects();
pageURL();
}
window.setInterval(pageScripts, 500);
});
var currentAnchor = null;
function pageEffects() {
// Popup Menus
$(".bannerMenu").hover(function() {
$(this).find("ul.bannerSubmenu").slideDown(300).show;
}, function() {
$(this).find("ul.bannerSubmenu").slideUp(400);
});
$(".panel").hover(function() {
$(this).find(".panelContent").fadeIn(200);
}, function() {
$(this).find(".panelContent").fadeOut(300);
});
// REL Links Control
$("a[rel='_blank']").click(function() {
this.target = "_blank";
});
$("a[rel='share']").click(function(event) {
var share_url = $(this).attr("href");
window.open(share_url, "Share", "width=768, height=450");
event.preventDefault();
});
}
function pageURL() {
if (currentAnchor != document.location.hash) {
currentAnchor = document.location.hash;
if (!currentAnchor) {
query = "section=home";
} else {
var splits = currentAnchor.substring(1).split("&");
var section = splits[0];
delete splits[0];
var params = splits.join("&");
var query = "section=" + section + params;
}
$.get("loader.php", query, function(data) {
$("#load").fadeIn("fast");
$("#content").fadeOut(100).html(data).fadeIn(500);
$("#load").fadeOut("fast");
});
}
}
This works fine for a while but after a few minutes of the page being loaded, it drags to a near stop in IE and Firefox. I checked the FF Error Console and it comes back with an error "Too many Recursions." Chrome seems to not care and the page continues to run more or less normally despite the amount of time it's been open.
It would seem to me that the pageEffects() call is causing the issue with the recursion, however, any attempts to move it out of the loop breaks them and they cease to work as soon as setInterval makes it first loop.
Any help on this would be greatly appreciated!

I am guessing that the pageEffects need added to the pageURL content.
At the very least this should be more efficient and prevent duplicate handlers
$(document).ready(function() {
pageEffects($('body'));
(function(){
pageURL();
window.setTimeout(arguments.callee, 500);
})();
});
var currentAnchor = null;
function pageEffects(parent) {
// Popup Menus
parent.find(".bannerMenu").each(function() {
$(this).unbind('mouseenter mouseleave');
var proxy = {
subMenu: $(this).find("ul.bannerSubmenu"),
handlerIn: function() {
this.subMenu.slideDown(300).show();
},
handlerOut: function() {
this.subMenu.slideUp(400).hide();
}
};
$(this).hover(proxy.handlerIn, proxy.handlerOut);
});
parent.find(".panel").each(function() {
$(this).unbind('mouseenter mouseleave');
var proxy = {
content: panel.find(".panelContent"),
handlerIn: function() {
this.content.fadeIn(200).show();
},
handlerOut: function() {
this.content.slideUp(400).hide();
}
};
$(this).hover(proxy.handlerIn, proxy.handlerOut);
});
// REL Links Control
parent.find("a[rel='_blank']").each(function() {
$(this).target = "_blank";
});
parent.find("a[rel='share']").click(function(event) {
var share_url = $(this).attr("href");
window.open(share_url, "Share", "width=768, height=450");
event.preventDefault();
});
}
function pageURL() {
if (currentAnchor != document.location.hash) {
currentAnchor = document.location.hash;
if (!currentAnchor) {
query = "section=home";
} else {
var splits = currentAnchor.substring(1).split("&");
var section = splits[0];
delete splits[0];
var params = splits.join("&");
var query = "section=" + section + params;
}
var content = $("#content");
$.get("loader.php", query, function(data) {
$("#load").fadeIn("fast");
content.fadeOut(100).html(data).fadeIn(500);
$("#load").fadeOut("fast");
});
pageEffects(content);
}
}

Thanks for the suggestions. I tried a few of them and they still did not lead to the desirable effects. After some cautious testing, I found out what was happening. With jQuery (and presumably Javascript as a whole), whenever an AJAX callback is made, the elements brought in through the callback are not binded to what was originally binded in the document, they must be rebinded. You can either do this by recalling all the jQuery events on a successful callback or by using the .live() event in jQuery's library. I opted for .live() and it works like a charm now and no more recursive errors :D.
$(document).ready(function() {
// Popup Menus
$(".bannerMenu").live("hover", function(event) {
if (event.type == "mouseover") {
$(this).find("ul.bannerSubmenu").slideDown(300);
} else {
$(this).find("ul.bannerSubmenu").slideUp(400);
}
});
// Rollover Content
$(".panel").live("hover", function(event) {
if (event.type == "mouseover") {
$(this).find(".panelContent").fadeIn(200);
} else {
$(this).find(".panelContent").fadeOut(300);
}
});
// HREF Events
$("a[rel='_blank']").live("click", function(event) {
var target = $(this).attr("href");
window.open(target, "_blank");
event.preventDefault();
});
$("a[rel='share']").live("click", function(event) {
var share_url = $(this).attr("href");
window.open(share_url, "Share", "width=768, height=450");
event.preventDefault();
});
setInterval("checkAnchor()", 500);
});
var currentAnchor = null;
function checkAnchor() {
if (currentAnchor != document.location.hash) {
currentAnchor = document.location.hash;
if (!currentAnchor) {
query = "section=home";
} else {
var splits = currentAnchor.substring(1).split("&");
var section = splits[0];
delete splits[0];
var params = splits.join("&");
var query = "section=" + section + params;
}
$.get("loader.php", query, function(data) {
$("#load").fadeIn(200);
$("#content").fadeOut(200).html(data).fadeIn(200);
$("#load").fadeOut(200);
});
}
}
Anywho, the page works as intended even in IE (which I rarely check for compatibility). Hopefully, some other newb will learn from my mistakes :p.