This is something that might be annoying or irritating for end user. Obviously, It's impossible
to prevent end user from closing the/any browser. Just think of this if it becomes possible!!!. That will be a horrible web world where everytime you will be attacked by sites and they will not allow
to close your browser until you confirm your shopping cart and do the payment. LOL:) You need
to open the task manager and might have
to kill the running browser exe processes.Anyways; Jokes apart, but I have one situation where I need
to alert/confirm from the user in any anyway when they try
to close the browser or change the url. Think of this: You are creating a single page intranet
asp.
net application where your employee can enter/select their TDS/Investment Declarations and you wish
to at-least ALERT/CONFIRM them if they are attempting to:[1] Close the Browser[2] Close the Browser Tab[3] Attempt
to go some other site by Changing the urlwithout completing/freezing their declaration.So, Finally requirement is clear. I need
to alert/confirm the user what he is going
to do on above bulleted events. I am going
to use window.onbeforeunload event
to set the javascript confirm alert box
to appear. <script language="JavaScript" type="text/javascript"> window.onbeforeunload = confirmExit;
function confirmExit() { return "You are about
to exit the system before freezing your declaration! If you leave now and never return
to freeze your declaration; then they will not go into effect and you may lose tax deduction, Are you sure you want
to leave now?"; } </script>See! you are halfway done!. So, every time browser unloads the page, above confirm alert causes
to appear on front of user like below:By saying here "every time browser unloads the page"; I mean
to say that whenever page loads or postback happens the browser onbeforeunload event will be executed. So, event a button submit or a link submit which causes page
to postback would tend
to execute the browser onbeforeunload event
to fire!So, now the hurdle is how can we prevent the alert "Not
to show when page is being postback" via any button/link submit? Answer is JQuery :)Idea is, you just need
to set the script reference src
to jQuery library and Set the window.onbeforeunload event
to null when any input/link causes a page
to postback.Below will be the complete code:<head runat="server"> <title></title> <script src="jquery.min.js" type="text/javascript"></script> <script language="JavaScript" type="text/javascript"> window.onbeforeunload = confirmExit;
function confirmExit() { return "You are about
to exit the system before freezing your declaration! If you leave now and never return
to freeze your declaration; then they will not go into effect and you may lose tax deduction, Are you sure you want
to leave now?"; } $(function() { $("a").click(function() { window.onbeforeunload = null; }); $("input").click(function() { window.onbeforeunload = null; }); }); </script></head><body> <form id="form1" runat="server"> <div></div> </form></body></html>So, By this post I have tried
to set the confirm alert if user try
to close the browser/tab or try leave the site by changing the url. I have attached a working example with this post here. I hope someone might find it helpful.
