Hello I am new in javascript, I am making chrome extension, this extension contains the setInterval command, I want to change the time with javascript to the textbox I have added to a website. This change should remain when I refresh the page, how can I do this.
My content script start document_end
var Refresh = setInterval(clickerStart,4000)
function clickerStart(){
var selection1 = document.querySelector("#\\30 ") !== null;
if (selection1) {
location.reload();
} else {
console.log("Islem Bulundu.");
};
}
//textbox
var Interval = document.createElement("INPUT");
Interval.setAttribute("type", "text");
Interval.setAttribute("value", " ");
document.body.appendChild(Interval);
If you are not handling with sensitive data, which I think it is the case, you can use localStorage or cookies to store and reuse data (the interval time) until the user returns to the page (after refreshing it or reopening it).
Here's an explanation on how to set cookies:
https://www.w3schools.com/js/js_cookies.asp
I am trying to read a label and append its value as a query string once the user hits the refresh button on their browser. The code I have so far is:
function AppendQueryString() {
var currUrl = document.location;
var trackingNbr = $("#lblTrackingNbr").text();
if (window.location.href.indexOf("?TrackingNumber=") <= 0 && trackingNbr !== null) {
document.location = currUrl + "?TrackingNumber="+ trackingNbr;
}
}
window.onbeforeunload = AppendQueryString();
The problem is, the trackingNbr variable is always null even though the label has the value before I hit refresh. What am I doing wrong or is there a better way of doing this ?
SessionStorage would be a good solution, with something like this:
sessionStorage.setItem("trackingNbr", trackingNbr);
When the refresh button is clicked, you can pull this value back from session storage easily:
var trackingNbr = sessionStorage.getItem("trackingNbr");
Security: Because this is session storage rather than local storage, the value will be cleared from the browser when the session ends. Note that only your domain can access whatever you put into either session or local storage. However, a knowledgeable end user can read the value by using developer tools in any of the major browsers.
I have a simple user survey form in which there is one section where the user needs to click on a link, read the page inside the link and then come back to continue the form. Currently, I have a parent HTML page from which I am providing a link to open a child web page in a different window/tab.
How can I obtain the time the user spent on the child window/tab?
listen to the user's click by something like
$('a').on('click', function(){
var d = new Date();
var curr_time = d.getTime();
//save in cookie1
})
and now in the other html page where the user is reading....do the same thing but only on window's unload
$(window).unload(function(){
var d1 = new Date();
var curr_time1 = d1.getTime();
//save in cookie2
})
save this also....
then when s/he comes back I mean on its onfocus you can subtract the values of these 2 cookies and divide by 1000 to get seconds as these time will be in milliseconds.
(cookie1 -cookie2)/1000 seconds //if the cookie thing is used
Does the user leave the page by clicking on the link, or is the second page displayed inside the first one? In the first case, you'll have to use a cookie to store the click time, in the second case, use a variable. Time can be retrieved using new Date().
Record the time of window open
Open the page in a named window
Set a timeinteval function (on original page) to check the location.href of the named window of say 1000 ms
if changed (to a finished/thankyou page) or not existing user must have finished reading
You should set a cookie or an DOM storage value while the page-to-read is open. In that page:
var isFocused = true; // just opened
var secondsLookedupon = 0; // eventually init with a saved value
window.onblur = function(){ isFocused=false; }; // use addEventHandler and co
window.onfocus = function(){ isFocused=true; }; // use addEventHandler and co
window.setInterval(function(){
if (!isFocused) {
secondsLookedupon++;
document.cookie.name = secondsLookedupon; // set a cookie in some way
window.sessionStorage.setItem("name", secondsLookedupon); // or use DOM storage
}
}, 1000);
and from the survey form page you can read that value from the cookie or domstorage whenever you need.
My Case: localStorage with key + value that should be deleted when browser is closed and not single tab.
Please see my code if its proper and what can be improved:
//create localStorage key + value if not exist
if (localStorage) {
localStorage.myPageDataArr = {
"name" => "Dan",
"lastname" => "Bonny"
};
}
//when browser closed - psedocode
$(window).unload(function() {
localStorage.myPageDataArr = undefined;
});
should be done like that and not with delete operator:
localStorage.removeItem(key);
Use with window global keyword:-
window.localStorage.removeItem('keyName');
You should use the sessionStorage instead if you want the key to be deleted when the browser close.
You can make use of the beforeunload event in JavaScript.
Using vanilla JavaScript you could do something like:
window.onbeforeunload = function() {
localStorage.removeItem(key);
return '';
};
That will delete the key before the browser window/tab is closed and prompts you to confirm the close window/tab action. I hope that solves your problem.
NOTE: The onbeforeunload method should return a string.
localStorage.removeItem(key); //item
localStorage.clear(); //all items
There is a very specific use case in which any suggestion to use sessionStorage instead of localStorage does not really help.
The use-case would be something as simple as having something stored while you have at least one tab opened, but invalidate it if you close the last tab remaining.
If you need your values to be saved cross-tab and window, sessionStorage does not help you unless you complicate your life with listeners, like I have tried.
In the meantime localStorage would be perfect for this, but it does the job 'too well', since your data will be waiting there even after a restart of the browser.
I ended up using a custom code and logic that takes advantage of both.
I'd rather explain then give code. First store what you need to in localStorage, then also in localStorage create a counter that will contain the number of tabs that you have opened.
This will be increased every time the page loads and decreased every time the page unloads. You can have your pick here of the events to use, I'd suggest 'load' and 'unload'.
At the time you unload, you need to do the cleanup tasks that you'd like to when the counter reaches 0, meaning you're closing the last tab.
Here comes the tricky part: I haven't found a reliable and generic way to tell the difference between a page reload or navigation inside the page and the closing of the tab.
So If the data you store is not something that you can rebuild on load after checking that this is your first tab, then you cannot remove it at every refresh.
Instead you need to store a flag in sessionStorage at every load before increasing the tab counter.
Before storing this value, you can make a check to see if it already has a value and if it doesn't,
this means you're loading into this session for the first time, meaning that you can do the cleanup at load if this value is not set and the counter is 0.
use sessionStorage
The sessionStorage object is equal to the localStorage object, except that it stores the data for only one session. The data is deleted when the user closes the browser window.
The following example counts the number of times a user has clicked a button, in the current session:
Example
if (sessionStorage.clickcount) {
sessionStorage.clickcount = Number(sessionStorage.clickcount) + 1;
} else {
sessionStorage.clickcount = 1;
}
document.getElementById("result").innerHTML = "You have clicked the button " +
sessionStorage.clickcount + " time(s) in this session.";
Try using
$(window).unload(function(){
localStorage.clear();
});
Hope this works for you
There are five methods to choose from:
setItem(): Add key and value to localStorage
getItem(): Retrieve a value by the key from localStorage
removeItem(): Remove an item by key from localStorage
clear(): Clear all localStorage
key(): Passed a number to retrieve nth key of a localStorage
You can use clear(), this method when invoked clears the entire storage of all records for that domain. It does not receive any parameters.
window.localStorage.clear();
for (let i = 0; i < localStorage.length; i++) {
if (localStorage.key(i).indexOf('the-name-to-delete') > -1) {
arr.push(localStorage.key(i));
}
}
for (let i = 0; i < arr.length; i++) {
localStorage.removeItem(arr[i]);
}
8.5 years in and the original question was never actually answered.
when browser is closed and not single tab.
This basic code snippet will give you the best of both worlds. Storage that persists only as long as the browser session (like sessionStorage), but is also shareable between tabs (localStorage).
It does this purely through localStorage.
function cleanup(){
// place whatever cleanup logic you want here, for example:
// window.localStorage.removeItem('my-item')
}
function tabOpened(){
const tabs = JSON.parse(window.localStorage.getItem('tabs'))
if (tabs === null) {
window.localStorage.setItem('tabs', 1)
} else {
window.localStorage.setItem('tabs', ++tabs)
}
}
function tabClosed(){
const tabs = JSON.parse(window.localStorage.getItem('tabs'))
if (tabs === 1) {
// last tab closed, perform cleanup.
window.localStorage.removeItem('tabs')
cleanup()
} else {
window.localStorage.setItem('tabs', --tabs)
}
}
window.onload = function () {
tabOpened();
}
window.onbeforeunload = function () {
tabClosed();
}
why not used sessionStorage?
"The sessionStorage object is equal to the localStorage object, except that it stores the data for only one session. The data is deleted when the user closes the browser window."
http://www.w3schools.com/html/html5_webstorage.asp
Although, some users already answered this question already, I am giving an example of application settings to solve this problem.
I had the same issue. I am using https://github.com/grevory/angular-local-storage module in my angularjs application. If you configure your app as follows, it will save variable in session storage instead of local storage. Therefore, if you close the browser or close the tab, session storage will be removed automatically. You do not need to do anything.
app.config(function (localStorageServiceProvider) {
localStorageServiceProvider
.setPrefix('myApp')
.setStorageType('sessionStorage')
});
Hope it will help.
Here's a simple test to see if you have browser support when working with local storage:
if(typeof(Storage)!=="undefined") {
console.log("localStorage and sessionStorage support!");
console.log("About to save:");
console.log(localStorage);
localStorage["somekey"] = 'hello';
console.log("Key saved:");
console.log(localStorage);
localStorage.removeItem("somekey"); //<--- key deleted here
console.log("key deleted:");
console.log(localStorage);
console.log("DONE ===");
} else {
console.log("Sorry! No web storage support..");
}
It worked for me as expected (I use Google Chrome).
Adapted from: http://www.w3schools.com/html/html5_webstorage.asp.
I don't think the solution presented here is 100% correct because window.onbeforeunload event is called not only when browser/Tab is closed(WHICH IS REQUIRED), but also on all other several events. (WHICH MIGHT NOT BE REQUIRED)
See this link for more information on list of events that can fire window.onbeforeunload:-
http://msdn.microsoft.com/en-us/library/ms536907(VS.85).aspx
After looking at this question 6 years after it was asked, I found that there still is no sufficient answer to this question; which should achieve all of the following:
Clear Local Storage after closing the browser (or all tabs of the domain)
Preserve Local Storage across tabs, if at least one tab remains active
Preserve Local Storage when reloading a single tab
Execute this piece of javascript at the start of each page load in order to achieve the above:
((nm,tm) => {
const
l = localStorage,
s = sessionStorage,
tabid = s.getItem(tm) || (newid => s.setItem(tm, newid) || newid)((Math.random() * 1e8).toFixed()),
update = set => {
let cur = JSON.parse(l.getItem(nm) || '{}');
if (set && typeof cur[tabid] == 'undefined' && !Object.values(cur).reduce((a, b) => a + b, 0)) {
l.clear();
cur = {};
}
cur[tabid] = set;
l.setItem(nm, JSON.stringify(cur));
};
update(1);
window.onbeforeunload = () => update(0);
})('tabs','tabid');
Edit: The basic idea here is the following:
When starting from scratch, the session storage is assigned a random id in a key called tabid
The local storage is then set with a key called tabs containing a object those key tabid is set to 1.
When the tab is unloaded, the local storage's tabs is updated to an object containing tabid set to 0.
If the tab is reloaded, it's first unloaded, and resumed. Since the session storage's key tabid exists, and so does the local storage tabs key with a sub-key of tabid the local storage is not cleared.
When the browser is unloaded, all session storage will be cleared. When resuming the session storage tabid won't exists anymore and a new tabid will be generated. Since the local storage does not have a sub-key for this tabid, nor any other tabid (all session were closed), it's cleared.
Upon a new created tab, a new tabid is generated in session storage, but since at least one tabs[tabid] exists, the local storage is not cleared
This will do the trick for objects.
localStorage.removeItem('key');
Or
localStorage.setItem('key', 0 );
You can simply use sessionStorage. Because sessionStorage allow to clear all key value when browser window will be closed .
See there : SessionStorage- MDN
This is an old question, but it seems none of the answer above are perfect.
In the case you want to store authentication or any sensitive information that are destructed only when the browser is closed, you can rely on sessionStorage and localStorage for cross-tab message passing.
Basically, the idea is:
You bootstrap from no previous tab opened, thus both your localStorage and sessionStorage are empty (if not, you can clear the localStorage). You'll have to register a message event listener on the localStorage.
The user authenticate/create a sensitive info on this tab (or any other tab opened on your domain).
You update the sessionStorage to store the sensitive information, and use the localStorage to store this information, then delete it (you don't care about timing here, since the event was queued when the data changed). Any other tab opened at that time will be called back on the message event, and will update their sessionStorage with the sensitive information.
If the user open a new tab on your domain, its sessionStorage will be empty. The code will have to set a key in the localStorage (for exemple: req). Any(all) other tab will be called back in the message event, see that key, and can answer with the sensitive information from their sessionStorage (like in 3), if they have such.
Please notice that this scheme does not depend on window.onbeforeunload event which is fragile (since the browser can be closed/crashed without these events being fired). Also, the time the sensitive information is stored on the localStorage is very small (since you rely on transcients change detection for cross tab message event) so it's unlikely that such sensitive information leaks on the user's hard drive.
Here's a demo of this concept: http://jsfiddle.net/oypdwxz7/2/
There are no such the way to detect browser close so probably you can't delete localStorage on browser close but there are another way to handle the things you can uses sessionCookies as it will destroy after browser close.This is I implemented in my project.
if(localStorage.getItem("visit") === null) {
localStorage.setItem('visit', window.location.hostname);
console.log(localStorage.getItem('visit'));
}
else if(localStorage.getItem('visit') == 'localhost'){
console.log(localStorage.getItem('visit'));
}
else {
console.log(localStorage.getItem('visit'));
}
$(document).ready(function(){
$("#clickme").click(function(){
localStorage.setItem('visit', '0');
});
});
window.localStorage.removeItem('visit');
window.addEventListener('beforeunload', (event) => {
localStorage.setItem("new_qus_id", $('.responseId').attr('id'));
var new_qus_no = localStorage.getItem('new_qus_id');
console.log(new_qus_no);
});
if (localStorage.getItem('new_qus_id') != '') {
var question_id = localStorage.getItem('new_qus_id');
} else {
var question_id = "<?php echo $question_id ; ?>";
}
you can try following code to delete local storage:
delete localStorage.myPageDataArr;
This should be a really easy "derp" question, but here it is:
I'm trying to set up a global variable in a JS file so that I can control when an action triggers. In my case, I want okBoxCall to only be called if firstTime is true. I have firstTime set to true initially, then I change it to false afterwards. My code is NOT working as it should however, as it still calls up okBoxCall more than once.
var Dialog;
var HUDWindow;
var smartPhone;
var firstTime = true;
$(document).ready(function(){
smartPhone = new SmartPhone();
initDialog();
initHUDWindow();
if(firstTime == true)
{
okBoxCall("Tutorial", "Welcome to McLarin Energy!");
firstTime = false;
}
});
What am I doing wrong? Obviously firstTime is not holding its change to false...
EDIT Forgot to mention that this is for a 3D game, not web pages. Cookies are not used.
I'm guessing you want to check whether this is the first time the user opens a page and open a tutorial if it is?
It is not possible the way you want to do it. Every time your page is loaded your script is evaluated again. So this means a variable firstTime is created and it is set to true. What you need is some persistent storage on the client to store whether it is the first time or not. You will need to set a cookie or call the localStorage API if you don't bother disregarding older browsers.
Your function should only be called once due to $(document).ready(...). So, I'm guessing you're reloading the page to get the alert to display again and again...
Maybe you should be looking at using cookies, not just a plain old JS variable..?
What is okBoxCall doing? If you have any error in okBoxCall firstTime = false will not be executed. Set the value before you call okBoxCall.
$(document).ready(function(){
smartPhone = new SmartPhone();
initDialog();
initHUDWindow();
if(firstTime == true)
{
firstTime = false;
okBoxCall("Tutorial", "Welcome to McLarin Energy!");
}
});