block the flow of javascript - javascript

If I write:
window.onbeforeunload = function(){ return 'exit?' ;};
I get a popup to stay / leave the page.
you can create a custom pop-up in html?
the problem is this:
if I create a popup html, which is activated only when you exit from the current page, and I will see him for half a second, then change page ... how can I fix this?
I need something (like the command alert) I block the page until you press a button.

You can't do that. Which is good, because it would be really damn irritating if every website could stop me from browsing away from the page until they felt like it.
onbeforeunload is the only mechanism you've got. It ensures the browser still has enough control to let me leave if I want to, and prevents you from sticking me in an alert loop or similar.

Related

How to get the id of a window.alert()?

I want to pop up a window.alert() if the user mouses out of an area when they haven't saved changes yet (for structural reasons, there are several forms and a common problem I've seen in other apps is making changes in multiple areas, submitting one and losing the rest) and automatically close the alert when they mouse back into the area. To do that, I need the id of the window that pops up, but I'm not sure how to get it.
The window does not have an id, and you cannot close it from Javascript. It is not a part of the DOM.
You can only open an alert() box, and then wait till the user closes it. Nothing else.
No alert() please :)
Actually an alert() will block further code execution anyway so even if you COULD close it programatically it would never actually execute that dialog-closing code.
You need something you can access through the DOM (like every other response here says).
Make your Javascript track the mouse location and upon leaving the area you overlay a dark translucent background or do a modal dialog
Techniques on creating modal dialogs
I would also advise adding a pointer-events: none; and position: fixed to the underlying content to prevent further action until the user actually goes back where they should be.
If you want real specifics on how to code this let me know. I'm hoping you'll travel down the rabbit hole and discover the wonders on your own, though. Much more satisfying.

How can I replace window.onbeforeunload with custom code?

For accessibility reasons, for my Chrome extension, I need to be able to replace all standard window.onbeforeunload popups with an in-page HTML substitute. I know how to create a substitute skeleton, that's trivial.
And I know the basic idea here is window.onbeforeunload = {my substitute code}.
What I don't know how to do is grab the text and code from each confirmation window that a page issues, and channel it into my substitute, so that the same message is shown as would be in the original popup and clicking my substitute confirm and leave page (or whatever) buttons yield the same result as the original popup.
How can this be done?
EXAMPLE:
You have my extension installed (don't ask what its purpose is, irrelevant).
You start writing a question on StackOverflow, then realize you already know the answer and go to close the tab.
Normally, a confirmation window would come up asking if you're sure you want to leave the page.
But because of my extension, instead, the whole page's HTML gets shoved down a bit to make room for a temporary HTML confirmation box is shown with the same text and the same two buttons that yield the same two results when clicked, all in-page. No pop-up.
The feature you're talking about is the window.onbeforeunload event, and unfortunately the only way it can be customized is to provide a custom string message for the user, because the potential for abuse is so high.
The api reference over at msdn for Internet Explorer states:
The default statement that appears in the dialog box, "Are you sure
you want to navigate away from this page? ... Press OK to continue, or
Cancel to stay on the current page.", cannot be removed or altered.
I take this to mean the dialog itself cannot be altered, all you can do is provide an additional context-specific message. I cant locate the same reference for Chrome, but it seems to be the same story there.
window.onbeforeunload = function() {
//all you can do is provide a message..
return "you have unsaved changes, if you leave they will be lost";
}

Required fields not met when closing window

I'm looking for the best way to go about "forcing" the user to fill a textarea.
For my work we have a system that keeps track of time spent on a particular "task". Some tasks are required to have a comment while others are optional. At the top of the page there is a timer, a textarea for the comments and a list of different tasks.
So far I have it so when the user tries to stop the timer, it won't stop until the comment is written (if it is required). When the paged is closed while the timer is running, an onbeforeunload function sends an alert warning that the comments aren't filled out and then the "Are you sure you want to leave?" warning pops up.
As far as I can tell there is no way to prevent the user from completely exiting the page. The idea we had was when the user closes the window, have another simple page open that just has a textarea and an instruction telling the user to write a comment. I'm pretty new to JavaScript and web development so I'm not entirely sure the best way to go about this.
Put that text area in a popup or iframe or modal window where you can control its closing.
On these window.close you can call the functions to validate the text area is filled or not.
Am not sure you can put that in a popup or not .but thats the only good way i can think of !!
There is no way to prevent the user from leaving a page.
Built in pop up blockers will also block the system from opening up popup windows onunload. Only way to allow onunload popups is if your system admins can update every browser to add an exception to the browser security settings.
It is impossible to make a web application act like a client application.

JavaScript problem toolbar=no

I have a simple logon page. When the user is validated, the window navigates to a new page. The javascript is window.open('http://www.google.com',"mytest",'toolbar=no'); My expectation is that when it navigates away from our logon page and opens the google site that the back button would be disabled. But it's not. Does anyone have any idea why?
It depends on your browser. Ultimately, all you can do with javascript's window.open() is tell the browser what you'd like it to do, but it's not obligated to do it. Browsers can and do ignore some directives based on user preferences.
I believe the option your looking for is 'location=no', as that hides the address bar and therefore the back button too. The toolbar is things like favorites/etc.
This is bad practice - what happens if the user has javascript disabled? If the browser prevents the js from removing the toolbar of the main window?
Instead, amend the logon page to detect whether the user is logged in before showing the login form. If logged in, show a message saying so instead of the form - that way, a user clicking back won't be a problem.
I find it very annoying when a website messes around with my browser window, and generally don't come back.
This is what worked for me. Instead of disabling the back key. I listen for on unload event. I then write the following in javascript:
window.onbeforeunload = function () { return "You should not press the back button while in this application. If you continue, your work will not be saved and you will need to log back in."}
Java Script pops a dialogue box with OK and Cancel options. If the user clicks cancel. The application stays right where they are. The script is embedded within the tags. For me this is the ideal solution. I found this at
http://www.hunlock.com/blogs/Mastering_The_Back_Button_With_Javascript

JavaScript To Get An Alert To Redirect When Closing The Browser Window

I'm trying to get this JavaScript to work properly. My intention is, when a user is trying to close the site page to get an alert saying "stay on current page or close" If they hit 'ok' I want it to close, if they hit 'cancel' i want it to redirect to another page. The problem is, when they try to go to another page on the same site, it gives them that popup. I want it to show only when closing, not when leaving the page to another page. I'm not sure if that's possible, I do appreciate your help and comments.
window.onbeforeunload = fget;
function yPop(url) {
var found = 1;
window.onbeforeunload = '';
window.location = url;
return false;
}
function fget() {
alert("Thank you for visiting our website, you are welcome any time! \n\n");
window.location = "http://NewLink.com";
return "\n________________________\n\n PRESS 'CANCEL' To Stay On The Current Page \n\n________________________\n";
}
The problem is, when they try to go to another page on the same site, it gives them that popup. I want it to show only when closing
Don't do this.
You can't detect closing only, but you can tell the difference between leaving by clicking on an internal link and other kinds of leaving, including external links, back button, closing and choosing/typing a new URL. In a script after the page has loaded, set the onbeforeunload event, then scan over all the document.links and test their .host against the current location.host. If they match, it's an internal link. In this case add an onclick event to them that removes the onbeforeunload event before returning true, allowing the link to operate normally without a warning.
Seriously, don't do this. It is incredibly irritating, arrogant and useless. Webmasters who employ leaving-pester scripts are condemned to the the fourth circle of internet hell, where they must spend the rest of eternity making stylesheets work on Netscape 4 using only ed, a worn toothbrush and a < layer>-tag.
you should use the window onbeforeunload Event.
http://msdn.microsoft.com/en-us/library/ms536907(VS.85).aspx
https://developer.mozilla.org/en/DOM/window.onbeforeunload
for jquery users :
$(window).unload( function () { alert("Bye now!"); } );
You may want to consider building a "You're about to leave this site" page instead.
The idea is that you wrap URLs on the page that aren't on your site to point to that page, letting the visitor know they're about to leave, and giving them a chance to go back, or proceed.
It's gentler than an unexpected modal dialog, it lets you format your messaging better, and it ultimately gives your users the exact same choice.

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