Jquery Effect Onunload - javascript

I would like to use the jquery slideUp effect when the user navigates away from the page just to make the page look cool as it closes.
I assume that I should use the onunload event but how can I delay the page closing long enough for the effect to run to completion.
One of the options that came to mind is effectively hijacking the page closing function, storing it in some variable and then executing it once I had run my effect but I have no idea how I would do that.
Any suggestions or alternative ideas are more than welcome

what you're looking for is the onbeforeunload event.
just a warning though... it should be really quick... or your visitors are probably going to hate it no matter how cool it looks
as to preventing the page from navigating away before the animation is done, that's a bigger problem... any animation is going to rely on setTimeout/setInterval and the page won't wait for those to complete before leaving.

Doing anything but closing the window when the users ask to is breaking a contract with the user. The browser window is not yours, it's the users, and no matter how cool the effect, it will inevitably annoy most of your users.
The onbeforeunload event is very restricted in what it can do. It must return a string, which is then used to prompt the user for a confirmation about leaving the page. It won't work for cool animations.

As far as I know, the only way to stop a user from leaving a page is the onbeforeunload event, which isn't cancelable. Instead, you return a string from that method, the browser prompts the user with a Yes/No dialog, life goes on. 276660 has more info about this.
I don't think you're going to have much luck with this one.

why not, instead of making a "cool" effect when a user simple want to go away from your website (even if the user closes the browser/tab the unload event will be fired) and annoying the simple user with that ... preventing him/her to return again...
...do that "cool" effect when a user reaches your website for the first time? as a normal intro effect?
I did that as a simple idea, you can see it here: http://www.balexandre.com/jmfc

I would agree 100% with Jonathan Fingland's answer, and add this.
In IE, (I'm not sure what versions support this, I know IE6 did) you can use some propriety meta tags to achieve fades etc when leaving the page. However, this is limited in browsers (IE only), so you're stuck for cross browser use.

You may find loading new content via AJAX would give you better control of effects and transitions, as well as reducing the annoyance factor to the user which can result from trying to hijack the browser actions in such a manner.
I would look at using a form of slider as mentioned above (see for instance http://webdesignledger.com/tutorials/13-super-useful-jquery-content-slider-scripts-and-tutorials),
or simply loading content panes in response to user clicks.

The only way I've found for delaying the window to close, is using an alert. If this is an acceptable compromise for your case, it will really delay the window destruction in memory, and allow your page timers to execute (of course, if user does not close the alert popup earlier than your animations finalize).
I recently used this approach so i could call a flex method through FABridge (which would otherwise be destroyed before the flex method call finishes). I'd like to hear your comments on this.

Related

window.open affect web page

I have a link that opens a new window using window.open. The pop up works fine, however the normal web page stops loading objects (images, scripts, ajax scripts) and sometimes the page doesn't load at all.
Here is my code:
MyWindow=window.open('player.php','Player','width=500','height=300'); return false;
Is there anything I am doing wrong?
Thanks,
Peter
First of all, please be more specific: tell us more about your browser and which version, and possible your OS. It could be more related to the browser than to the web content.
Then on to the possible problem; you start with saying "I have a link that ...".
To me that sound like you use <a href="javascript:DoSomething()">. Or perhaps <a href="#" onclick="DoSomething()">.
I tried both in some modern browsers: Chrome v37, IE v11. Both browsers did not produce what you describe:
- Chrome v37 will happily keep on loading, even if I immediately click a "window.open()"-link on top of a (huge) webpage;
- IE v11 will someshow show "false", which is strange, but still not what you got.
In some cases I also got to deal with the popup blocker.
A general tip might be to NOT USE <a href> for things like this. Behaviour seems inconsistent across browsers, also these days there are better alternatives, such as <span onclick="">...</span> and <button onclick="">...<button> or by using JQuery or other frameworks (which I do not know much about).
Although this many not be a conclusive answer, maybe this can help you experiment on your own, and think about possible causes or alternative ways of doing things.
The behaviour you describe should definitely NOT normally happen. This is confirmed by robbmj's JSFiddle, that fails to reproduce the problem. That's evidence that something is going on in the main page that is not plain vanilla page loading, or your "link opening" has something unusual to it. Apart from the syntax error (you use four parameters, not three).
Since you do not supply information on either of these points (how do you load the main page? How do you trigger the popup-opening code?), we do not even know if the problem
might be browser-related; I'd start and try to test things in IE, Chrome and Mozilla to see
whether anything changes; this might provide some useful insights.
One possibility
A very strong possibility is that your inadvertent fourth parameter goes into the window.open() "replace" parameter, which is a boolean, and triggers undefined behaviour or simply an error that stops everything. You should have things somewhat working in IE and not working at all in Firefox.
You should also be able to see whether this is the case by using Firefox and the Firebug extension, or the Web Developer Console in Chrome.
Another possibility
A more esoteric possibility is that the way you define the link might make the browser believe you've actually moved on to another page, so that there's no point in continuing loading the current page. Depending on the browser, this might have to do with how the link is defined and could be remedied by defining it some other way.
For example it could conceivably happen if you had
...
which I suspect is what led user Tomzan to ask, "is the link something like javascript:...?"
So if this is the case, try with this instead (this works for me in IE9/Chrome/FF):
link
function openPopup() {
MyWindow = window.open('player.php', 'Player', 'width=500, height=300');
// Also try the following. You won't probably like the results (it should send the
// popup window behind), but if it works, it proves we're dealing with a browser
// issue there.
// Blur and refocus
// MyWindow.blur();
// window.focus();
// Just focus
// window.focus();
return false;
}
Workaround
A possibly acceptable workaround could be to disable the link altogether (or hide it via CSS), and only reactivate/show it upon main document being ready. This sidesteps the problem, even if user experience could be somewhat worse due to a longer wait.
But if it's so likely that a user clicks on the link before waiting for the whole page to load, I'd also consider not automatically loading the rest of the page at all, and reorganize information to provide a more streamlined navigation. Or maybe distribute it on two sequential pages. Again, unfortunately you did not supply enough information to do more than guess.
As you probably know, JavaScript is single threaded. Every event is queued until there is idle time for it to be executed.
In the case of window.open, both windows must share a single context to keep it thread-safe because the opened window can access to it's parent using window.opener.
I don't know how browsers implements it, but we can guess two possibilities:
Idle time is shared between the two windows. It means if the popup does many blocking statements, it can freeze the main window's events.
Only one of the two windows can be active, which depends on which one has the focus. In that case, all events may be paused in the main window when you're using the popup.
If you want a more precise answer, I need more details about your code.
document.addEventListener("DOMContentLoaded", function () {
//whatever the code
MyWindow=window.open('player.php','Player','width=500','height=300'); return false;
}, false);
Try to wrap the code in SetTimeout
setTimeout(function () {
window.open( .. )
}, 0);
Your document should be loaded first, then popup should be open, So write your javascript code in the scope of $(document).ready().
enter code here
$(document).ready(function(){
$("#clickme").click(function(e){
MyWindow=window.open('player.php','Player','width=500','height=300'); return false;
});
});

jQuery / Javascript event to detect page change cancellation

A bit of a curve ball request that might well not have a solution, but worth asking...
We have a heavy AJAX-based website and we rely on modal/loading screens fairly heavily to indicate when something important is happening. All works well.
We also have some operations that trigger full page changes which can take a couple seconds. I'd like to impose the same modal/loading screen when those changes kick off, however- if a user cancels the page load I'd like to detect it and take the loading modal down. Else it'd just sit there forever.
I can watch for the Escape key being used but is there a way to detect the cancellation in a more generic way that'd also work when initiated by the browser's cancel controls?
Thanks
P.S. To be clear, I'm talking normal page changes in this case. Mentioning the AJAX used elsewhere was just to explain why I want the loading screen now; for consistency. Otherwise I think we'd all agree it's abnormal to have loading screens just to navigate around a site.
RESULT
Evidently not possible.
As niklas found:
But now I see what you're tying to do and i found this https://stackoverflow.com/a/1776490/3877639. I don't like your odds I'm afraid.
Started answering, then I saw Carlos answer and thought I might have misinterpret your question. I'll leave my first answer in the bottom, just in case it might be of some use to you either way.
You wish to detect the page load being canceled. But if the page load is canceled, won't the ajax call fail? Couldn't you listen for that some how and then take down the modal/loading screen?
Don't know if you use jQuery's .ajax(), but then it's easy doing stuff if there's any errors.
What you are looking for is the onunload event. However, the browser support is not so good (as you can see in the link).
There's also the onbeforeunload event that has better browser support, but it triggers a browser dialog you can't override. Just send a text to. Then the user can choose to stay on the page or leave it/close it.
Basically you can abort the XMLHttpRequest the ajax call returns with jQuery.
See this

Waiting event before closing window using onbeforeunload

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.

How can I delay leaving a page via javascript?

I'm trying to get add a delay of 1000ms before a person leaved the page. I'm using the beforeunload event to start a jquery animation and would like it to finish before the page leaves.
I'm not concerned with older browsers, IE9, latest safari, chrome and FF4 are all i'm interested in.
Edit: Well I was hoping to implement it when just navigating internal pages. Sure I can make all my internal links a javascript call, but I would have preferred a less brute force method.
Also, I'm not stopping people from leaving the page, not even making them wait a huge long time, 1 second for a fade out? Thats no worse than every game I play fading out when I select quit.
Now had I asked how do I prevent a person from leaving a page, then yes all the "don't do it" would have been deserved.
Firstly, if people want to leave your page, don't put any barriers or difficulties in leaving it. Just let them.
Konerak said it well...
Using a blocking action is acceptable when the user is about to lose data by leaving the page, but using them for animations and gimmicks will quickly annoy your users.
Secondly, you can only prevent automatic closing with a blocking action, such as an alert() or prompt(), which temporary blocks the browser's viewport, waiting for user response.
jsFiddle.
Well I was hoping to implement it when just navigating internal pages.
I know it’s four years later now, but I wanted to point out that, within the bounds you’ve described, you can do this.
$(document).on("click", "a", function (e) {// Listen for all link click events on the page (assuming other scripts don’t stop them from bubbling all the way up)
// Stop the link from being followed.
e.preventDefault();
// Grab the link element that was clicked
var linkClicked = e.target;
// I'm using setTimeout to just delay things here, but you would do your animation and then call a function like this when it’s done
window.setTimeout(function () {
// Simulate navigation
window.location = linkClicked.href;
}, 1000);
return false;
});
It’s still inadvisable:
I suspect it would get annoying to users pretty quickly
Without additional code, this would prevent users from command/control-clicking to open links in a new tab.
8 years later and I'm about to code this for my own website, specifically as a fade between pages. But I'm only going to do this for navigating between pages within my site, and I'm not going to use window.onbeforeunload or window.onclick. I attach a click event handler to specific "buttons" on each page. pointer-events is even disabled for other elements, so the event's element scope is very limited. The code is a switch() statement with cases for each "button". Each button navigates to a specific page within the site.
I don't think this is bad web page or web site behavior. A 1 second delay when transitioning between pages is not going to annoy users. I think you might be able to get 2 seconds or more out of it, if you include the time it takes to load the destination page, which can also fade in gradually in as it loads data.
It's visually elegant, especially compared to typical news/info sites with flex layouts that shift all over the page while they load. Those pages spend 2 or more seconds shifting stuff around before you can read anything.
My site is already filled with CSS and SVG animations, so adding this to the internal page navigation is no sweat for this project. If you limit the element scope of the user events and you make the delays small, this is good behavior, not bad behavior, IMO. Visual elegance has value.
EDIT- As I get into it, I see that for one group of similar pages I can achieve better cross-fading between them by consolidating them into one page. That way I can truly cross-fade between each sub-page instead of fading out one page then fading in another.

Javascript: Alert user without using an alert box

I'm trying to find an elegant way to inform a user that s/he is about to be logged out and I know that most browsers will give you some indication that a hidden tab has an alert box open. I would like to duplicate this functionality without actually showing an alert box.
I have thought about forcing the tab/window to gain focus, but that is quite obtrusive and I hate it when websites do that to me, so I'm looking for something a little more subtle.
Any ideas?
Edit/Clarification: I already have a div that pops up if they are about to be logged out. My problem is that if they are on another tab, they won't be able to see that div, so I would like some way to notify the user that something important has happened on my tab so they go check it out and see the logout notice.
The favicon idea listed below is an excellent idea, any others?
Here's an interesting way that comes to mind. When its time to be logged out, change the website's favicon dynamically. Newer browsers should be ok with it.
Look here: Changing website favicon dynamically
Some techniques I've seen:
Some sort of sound that's played (I think it's done with Flash in the case I'm thinking of, but maybe it's possible with HTML5's audio tag)
Flashing/alternating favicon
Use JavaScript to change the page title tag every 2s or so
You could create a page that informs them they will be logged out in a certain amount of time with a button that would allow them to maintain their session. Or maybe you could use a lightbox modal popup window (example here).
Why not swap out a div styled how you want to change to let them know they will be logged out soon? Then, you can simply have it as a portion of your page with all the same style and formatting?
For example, your normal page has some sort of page element with visibility:block; and then before they will be logged out, you change that to visibility:none; and change your other element (in the same place) to have visibility:block;
Does this idea make sense? You have to be able to detect when this is happening with Javascript already to alert, so instead of altering you are just swapping out display elements.
I hope this is helpful,
-Brian J. Stinar-
it probably doesn't go with what you're after but a simple modal window is probably a good idea? i know it doesn't alert the user instantly, and they won't see it unless they switch back to that tab, but it's unobtrusive and i believe most users would prefer not to have something rammed in their face!
If this notification is to be triggered by a user clicking "log out" or the likes then they will see it and it won't be as intrusive as forcing them to stop what they are doing and close the alert box.
And if it's due to time out or something similar then the user isn't overly concedrned or they would still be on that tab.
I think that this serves the best purpose in terms of usability as people don't want to be hassled or have their workflow broken by an alert shoved at them! A perfect example is Microsoft TFS which would constantly throw alerts at you when you got signed out, which got really frustrating, really quickly
so my answer is think how the user would like to be notified in the least obtrusive way :-)

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