This question already has answers here:
Identifying Between Refresh And Close Browser Actions
(13 answers)
Closed 6 years ago.
I am currently looking at the "unload" event of a window to try to determine how the "unload" event was triggered, but am having little success. Is there a way to determine how the javascript event was triggered?
Page Refresh
Back Button (or navigate away from the page)
Closing the Browser
Essentially I need to execute some code only when the browser window is being closed, not refreshed or navigated away from.
Purpose: When a customer does an update of our software, the update will redirect their first Internet request to an offer page. There is a button for a "Do Not Bother" option, but some users will simply close their browser. Upon closing the browser, I need to duplicate the "Do Not Bother" functionality so the user no longer gets redirected to the offer page. Simply attaching to the "unload" event will not work due to the different ways of leaving a page.
No, and if there was it would be browser dependent.
What kind of code are you trying to run when the user closes the page?
Is it to logout the user?
Then the user would not be logged out if the browser crashes or the network connection breaks (and probably not if the computer goes to sleep/hibernation mode).
If it is for logout-purposes you should probably use a timestamp variable at the server that gets updated with every request (or use a ajax-ping), and logout the user if it hasn't been seen for a specified time.
Update: Found this answer here at stackoverflow.
Yes, there is a solution!
I've designed a solution based on onBeforeUnload+onLoad events, HTML5 local storage and client/server communication. See the details on https://stackoverflow.com/a/13916847/698168.
I use a method of doing keyboard "sniffing", in that it looks for keydown's of "F5", "ctrl+r", "alt-f4", "backspace" and others, and if it finds them flowing through the keyboard event queue, it sets boolean variables appropriately to trap that status... then I use a "onbeforeunload" function handler, which tests against those boolean status variables to decide what to do.
You can even shut down various keyboard strokes (like "ctrl+n" or "F1" for instance) by using preventDefault(), bubbles=false and returnValue=false in your keyboard handling.
This stuff is not for the faint of heart, but its certainly doable with some persistence and lots of cross browser testing!
Related
Context :
I have developped an application which require authentification. This application uses events for dialoging with a server. When the server answer, some events are send to the client (UI).
Problem :
When the user close the page, it is necessary to make a logout on the server. With my architecture, it's easy to call a method which perform this logout. But i would like that the user show the logout progress before closing the webpage. In fact, i would like to close the webpage only when a specific event (for example : disconnection_success), is well received.
Moreover, it's verry important to not launcg another webpage because event is received on the first webpage when the logout is successfull. (Because dialog is done throw XMLHttpRequest)
Test :
I already do some test using onbeforeunload but it seems that is difficult to customize the popup.
Do you have some ideas to resolve the problem ?
BR
There are some issues with this, but you're on the right track. You're right in that you should use onbeforeunload because it is the only event that you can have triggered upon the closing of the browser window. (I know you can use onunload but at that point you have no time to do anything.) The issue here is how much code do you want to execute. The onbeforeunload doesn't allow you much time before it starts to unload the page.
BTW, there are two different scenarios with onbeforeunload:
If you return a string inside the onbeforeunload event, it creates the pop-up that you were referring to. The issue here is that with the pop-up, you won't have enough time to execute code
The other option is not returning anything. Instead, call your logout methods. This should give your code enough time to execute before closing
I actually had a question very similar to this and ended up solving it myself: How to logout during onbeforeunload/onunload using Javascript
In your question you state that you want to have a progress bar displayed when they log-out. This is impossible to do when the user closes the browser. At the moment they close their window, you have lost all control, except for in the onbeforeunload (and onunload but don't use this), and that is why your code needs to be executed there. With that being said, you could anchor your logout button (I'm assuming you have one on your application) and have it display the progress bar.
Just think about what could happen if you actually did have that kind of control - where you could pop up windows and progress bars when the user is trying to close their browser window. You could pop up anything and restrict the user from having any reliable functionality. That is why it was programmed that the onbeforeunload (and unload) events are the only ones possible to access the closing of a browser. These events have some pretty strict guidelines to them that prevent any kind of possible mis-use. I understand the problem you're having, I was there and it stinks, but I think that is your only option if you were going to use onbeforeunload.
This question already has answers here:
Communication between tabs or windows
(9 answers)
Closed 6 years ago.
I am building an app that performs a lot of client side data downloading and processing. The data processing is isolated from the main app by being processed in an iframe that resides on a sub domain. It is this iframe that downloads the data. Communication is via postMessage.
Everything works fine, except it could be better.
If the user opens extra tabs/windows, the app currently reloads all the data and may even do duplicate processing work, which isn't a problem other than that it slows everything down and pages take longer to load.
What I would like to do is have each top level tab/window communicate with just the one processing iframe, which could be reinstated if the original window is closed. The trouble is, these are not opened via javascript, but via the normal browser methods to open links in tabs so I can't get a reference to the iframe that is needed to send a message.
Is there anyway I can communicate the window reference for the iframe to the other tabs so that they can communicate with it via a postMessage? Could this in someway be achieved using shared workers?
I realize I could use shared workers for the whole processing task, but this would have it's own problems as the the data comes from third party domains, which can't be accessed from within a worker.
Only compatibility with the latest versions of all major browsers is needed.
Edit: I've just discovered that SharedWorker is not yet implemented in firefox, so I guess that is not going to work. Any other way I could achieve this?
Edit 2: I've discovered that you can use :
var win = window.open('', 'my_window_name');
to capture a reference to an iframe from any other window. However, if the iframe does not already exist then it will open it as a window. Even if it is closed immediately, it causes a flicker and causes the 'popup blocked' messages, making it unusable.
In case any one else finds this, I've come up with a solution. It is somewhat hacky and requires further testing. But so far it is working. It works cross domain if that is needed.
It uses a combination of two tricks.
The first is to use
remote_window = window.open("", "remote_window_name");
to fetch a reference to the window. This works because if a window is already open with the given name then a reference is returned to it rather than opening a new window.
It does however have the problem that if the iframe does not exist then a new window will pop up. Local storage is used in order to prevent this. When a window/tab loads, it checks localStorage to see if there is another page already with a shared iframe. If not it inserts the the iframe and sets a flag in local storage to say that it is available.
As a last ditched resort, if the window still opens, a try block is used to close the newly opened window. The try block prevents cross domain errors. This means that the worst that will happen is the user sees a window pop up and disappear or they will see the 'enable pop-ups' message. I've yet to manage to trigger this in testing - it is only an edge case fall back.
try {
if(store_window.location.href === "about:blank" ){
remote_window.close();
remote_window = insertIfame();
}
} catch(err) {
}
An onunload event is added which removes the flag should the page be closed.
Also a setInterval is created that constantly refreshes a timeout flag. I have it running 4 times a second; when a second window/tab is loaded it checks that the iframe flag has not timed out before trying to communicate with it. This is a small overhead, but far less than the cost to me of having that second iframe loading. This serves the purpose of preventing stale data if the browser crashes or the the onunload does not fire for any reason. I include a small leeway when checking the timeout - currently 1 second - in case the main window is stuck in a loop. The leeway is only on the timeout, not the unload event which removes the flag entirely.
The flag needs to be checked every time a message is sent in case the original window with the iframe has closed. When this happens the iframe is reinserted in the first open window that requires it and the flag is reset.
Sending messages back is easy. Just use the event.source property of the receiveMessage -this points to the sending window.
One final edge case to account for is if the primary window closes whilst it's iframe is mid process for a secondary window. Theoretically this could be dealt with by using an onunload event in the iframe to send a message back to any windows with data in process. But I've yet to implement it and it may not finish before the page unloads. Another way of dealing with it would be by having a timeout in the secondary window which checks the flag and retries, I'll probably go this route as the messages already have timeouts attached.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Disable browser's back button
Is there any way to disable browser(specifically IE) BACK button, FORWARD button, REFRESH button by javascript. So that, when ever any user will click on any button nothing will happen.
No, you cannot reliably, reasonably do that. Even IE's "kiosk mode" allows back, forward, and refresh (via keyboard shortcuts).
On an actual web page (a real page out on the web), disabling back/forward/refresh would of course be extremely inappropriate behavior and I assume that's not what you're trying to do. (Instead, use history libraries and such to ensure your page/web app actually works with the back and forward buttons to do what the user expects.)
Mind you, if you provide a link that opens a new window (which will probably actually end up being a new tab in most modern browsers), your page will be the first page in that window's history and so the Back button will automatically be disabled. And if your page doesn't offer any links anywhere else, it'll stay that way. And if the user hasn't gone Back, by definition they can't go Forward. Nothing you can do about Refresh, though.
If you have a genuine reason for actually disabling those actions (some kind of intranet application, that sort of thing), you'll probably have to distribute an actual application (for instance, .Net app via No Touch Deployment or similar) that incorporates a web browser control, which gives you the HTML/CSS/JavaScript environment but with dramatically higher control over that environment.
As far as I know, you can't modify the buttons in a browser with scripts.
Since you're working with IE, you may be able to use either VBScript or JScript, but I doubt you'll be able to disable the reload button.
More reading:
http://www.webdeveloper.com/forum/showthread.php?t=62177
i'm looking for a reliable way on how to detect when a user closes the browser/tab in order to display a warning message (i'm having a shopping cart which uses sessions).
i've googled and couldn't find a proper solution - window.onunload will display a message every time i'm refreshing the page ..
any ideas?
thanks
You can't tell the difference between closing, reloading, back/forward etc.
beforeunload is fired on all of them.
Depending on if you launched the window yourself, you could run your code before calling window.close(), but this won't be called if the user closes the window themselves.
I don't believe such a thing is possible.
The browser can fire an event when the page (un)loads, but who's to say wether the user is navigating, or closing the browser/tab?
I am writing an ASP.NET application that tracks the user's scores and info (it is a
training application) to an access database, if any one closes the browser directly I want to display an alert message.
My problem is that I cannot use the unload event because When I pressed any ASP.NET button at that time unload event occurs. What event should I be using that will work for IE and FF?
I want to handle event Browser close(X).
The onbeforeunload event will only give you the confirm box with a message. You can't put more functionality into it.
What you should be doing is having both the window unload eventhandler and the logout button click eventhandler call the same logout method. You don't need to stop the user and ask them to press your button, your button should be just another way of doing the same thing.
Also: have you considered SCORM?
Not sure you know what you want to do here. ;-)
Do you want to prevent the user completely from closing the browser until a certain point in the trainig? If so, have you considered using a modal and maximized window? You should be able to maximize the window without the titlebar, buttons and menus.
Or if you just want to keep track of the progress, scores or similar, then you could use cookies handled by the browser via JavaScript. Just bear in mind that this will keep the data on just one machine for the student.
If you just want to warn the user that he is about to leave the training course, you could use onbeforeunload
I think others have adequately answered your specific question, but Tooney raises some good points. To expand on these. Where are you currently maintaining your the state? Are the scores stored in cookies, within a server-side session or do your persist them page by page within the database.
Assuming this isn't a cheap and cheerful solution, then I would suggest you consider persisting results page by page, as it is minimise the loss of information caused by a premature exit (either by design or accident). Of course, you then need a process to cleanup incomplete training session.
You could still use the onbeforeunload function to trap user exits, but personally I don't like UI's that double check users actions.
Good luck.