Identifying Between Refresh And Close Browser Actions

Solution 1:

There is a solution.

I wanted to disconnect the user on the server when the tab or browser window was closed, but not when the page was reloaded (you may want to differentiate reload/close events for a different purpose but you may benefit from my solution). I ended up with the following process, based on HTML5's local storage and client/server AJAX communication:

1. on your page, add an onunload to the window to the following handler (pseudo-javascript):

   function myUnload(event) {
       if (window.localStorage) {
           // flag the page as being unloading
           window.localStorage['myUnloadEventFlag']=new Date().getTime();
       }
   
       // notify the server that we want to disconnect the user in a few seconds (I used 5 seconds)
       askServerToDisconnectUserInAFewSeconds(); // synchronous AJAX call
   }
   

2. on your page, add a onloadon the body to the following handler (pseudo-javascript):

   function myLoad(event) {
       if (window.localStorage) {
           var t0 = Number(window.localStorage['myUnloadEventFlag']);
           if (isNaN(t0)) t0=0;
           var t1=new Date().getTime();
           var duration=t1-t0;
           if (duration<10*1000) {
               // less than 10 seconds since the previous Unload event => it's a browser reload (so cancel the disconnection request)
               askServerToCancelDisconnectionRequest(); // asynchronous AJAX call
           } else {
               // last unload event was for a tab/window close => do whatever you want (I do nothing here)
           }
       }
   } 
   

3. on the server, collect the disconnection requests in a list and set a timer thread which inspects the list at regular intervals (I used every 20 seconds). Once a disconnection request timeout (i.e. the 5 seconds are gone), disconnect the user from the server. If a disconnection request cancelation is received in the meantime, the corresponding disconnection request is removed from the list, so that the user will not be disconnected.

This approach is also applicable if you want to differentiate between tab/window close event and followed links or submitted form . You just need to put the two event handlers on every page which contains links and forms and on every link/form landing page.

Note that I use the unload event instead of the beforeUnload event in order to manage links to attachments properly: when a user clicks on a link to an attachment (e.g. PDF file), the beforeUnload event is dispatched, then an open/save popup is raised, and nothing more (the browser does not change the displayed page and does not dispatch the unload event). If I were using the beforeUnload event (as I did before), I would have detected a page change when there is none.

This approach is limited to the browsers which support HTML5 local storage, so you would probably use specific approaches for old browsers such as MSIE7.

Other approaches based on the event.clientY are not reliable because this value is negative when clicking on the reload or tab/window close buttons, and positive when keyboard shortcuts are used to reload (e.g. F5, Ctrl-R, ...) and window closing (e.g. Alt-F4). Relying on the event X position is also not reliable because the buttons are not placed at the same position on every browser (e.g. close button at the left).

Solution 2:

Unfortunately inspecting the clientY/pageY value of the event, as suggested by some of the answers here, is not a reliable way to determine if the unload event is being fired by as a consequence of the user closing the page.

The reason clientY/pageY is negative when you click the browser's close button is because the close button is positioned above the top of the document (i.e. above pixel 0), but so is the reload button meaning that clicking the reload button will also result in a negative value for clientY/pageY.

Going down the path of inspecting the x co-ordinate of the event is also problematic because the browser close button is not always on the right hand side of the window (e.g. it's on the left in OS X) and because a window can be closed by closing its tab or via the keyboard.

Solution 3:

Maybe someone is still searching for an answer...

You can use SessionStorage for that! SessionStorage is not cleared when the page is reloaded but when it is closed. So basically you could set a key/value pair when the page is loaded, but before that you check if the key/value pair exists. If it does exists it means that the page was reloaded, if not it means that the user opened the page for the first time or in a new tab.

if (sessionStorage.getItem('reloaded') != null) {
    console.log('page was reloaded');
} else {
    console.log('page was not reloaded');
}

sessionStorage.setItem('reloaded', 'yes');

This way you can doStuff() with the onunload event (user leaves the page), and otherStuff() if the key/value pair is set (user reloaded the page).

Solution 4:

This is a huge hack with some limitations but it will work in most practical cases.

So if you just need something that works when users use the ctrl+r or cmd+r shortcut, you can keep track of whether r is pressed when whatever you need to do upon reload/close gets run.

Simply create keydown and keyup event listeners that toggle a rDown variable.

let rDown = false;
window.addEventListener("keydown", event => {
    if (event.key == 'r')
        rDown = true;
})
window.addEventListener("keyup", event => {
    if (event.key == 'r')
        rDown = false;
})

Then you have your "onunload" event listener where the listener function has an if statement checking if rDown is true.

window.addEventListener("onunload", () => {
    if (!rDown) {
        // code that only gets run when the window is closed (or
        // some psychopath reloads by actually clicking the icon)
    }
});

Solution 5:

Today I had the same problem and found a possible solution that I want to share with you.

While thinking about what could help to discern between refresh and close, cookies came to my mind. I remember that setting a cookie without an explicit expiration date, renders it available only for the current session. And a current session is clearly valid until the browser is closed. This does not include closing a tab, but my problem was about user authentication and I didn't want to logout the user only for having closed a tab (I think that's the same approach as the ASPXAUTH cookie of ASP.NET).

So, I put a simple cookie in the document.cookies collection when user logged in and checked it on page load: if cookie was still there it was a refresh or a reopened tab and user data was kept, if cookie was not present session had expired so user data was cleared (same as an explicit logout).

Hope this approach can be useful to someone else!