How to intercept back button in Sammy.js - javascript

I´m currently using Sammy.js in my Single Page Application and want to notify the user if he tries to leave a site with changed content.
Is it somehow possible to intercept the back command or any other routing change to display some hint before?

See my answer here for one way to do what you're looking for. The group I work for actively uses this technique to show a dialog whenever a user tries to navigate away from a page that has been modified but not saved.
Outside of the solution I point out there, you cannot prevent the back button from actually navigating them. If you could do that with JavaScript, that could be easily abused to keep users on a page until they closed the browser.

Related

Change back button behaviour of browser

Posting without a target so that a web page reloads seems useful behaviour for some things - such as writing a login page. I have implemented a calendar in PHP which takes advantage of this. It reloads an object from the session (or creates a new one if not present), applying any changes that result from the post then saves the object back to the session. The problem is this. If I hit the back button I don't want to go back through every click of the calendar button but would rather jump back to the page before arriving at the calendar page. Not only that, if I do go back one calendar page after another I get an annoying "confirm form resubmission". I have implemented an incrementing value after the # for each post so that I might be able to use window.onhashchange. The problem is that window.onhashchange never fires so I am unable to intercept the back button and pop the history stack. Any ideas? Am I better off coding on the server side with javascript?
Well I solved one problem. My form subclass in PHP defaults to using POST as I understand this is more secure. This causes the annoying resubmission problem when using the back button. I now use GET in my calendar page which solves this issue. I am still bemused by JS debugging in Netbeans. I have never got script to stop on a breakpoint within a single document. I have previously had it working with an external javascript source but this no longer works. If I can output to console but there is no window in which to see the output. I am told window.alert no longer works for some events in Chrome. I am completely blind! To add to the irritation, it took me a while to realize was that the javascript file was cached and changes would not be reflected in behaviour. I have put a random number into the script tag which fixes this issue. As I am debugging using netbeans connector in Chrome I have no idea why this does not force the js file to refresh. All in all, this appears to be a pretty shambolic toolchain.

Browser back button and javascript

It's possible to show some message on the page when you set mouse cursor on the browser back button? I don't want to use window.onbeforeunload, because it's irritating. I use ajax and I want to inform users that if they want to go back to the previous page on my web portal they should use a different button.
Is it possible to do it?
Thanks for your help
It is not possible to handle the mouse moving on the browser buttons, these are not part of the DOM that your scripts can handle.
There is an answer available here, which proposes a way of preventing users going back through the browser's back button.

Understanding anonymous user in Drupal 7 form using Jquery

I have site which contains many links. User can open links in new window. User can log out from one window. If they do so and click on the other window of my site then I want to give an alert to the user saying that "Please login to continue". My questions are:-
Is this possible in Drupal 7?
Is there any extra module to support this.
If there is no contributed module available for this then my idea is to register a click event on the page(document) inside JQuery which will always check if user is authenticated or not. I want to know that which function in Drupal will help me in understanding authenticated user of site in JQuery.
Please share if any other option available to achieve this goal.
This is not an easy task, but I am going to explain how I would do so (without too many details):
Create a web service which receives a cookie and returns whether it represents a live session or not.
Use the visibility change javascript event to detect when a user leaves the browser or comes back in. When you notice the user has come back to the browser, perform an AJAX call to the server you set up in step one. You should provide the cookie stored in the browser, and expect a boolean answer.
Depending on the response given by the server, display a modal dialog with Javascript showing a login form orwhatever you consider necessary.
Note: This method will only work if the user is using a browser supporting visibility change events, and can be bypassed disabling Javascript code execution. In addition, the user will still be able to see the content if the browser is not the focused window (for example, there are two opened windows, each of them covering one half of the screen. The event will not fire until the focus comes back to the "forbidden" window).

How can I get links to a redirect page to show up in the browser's history?

A website contains a "random" link, which loads a url that returns a 307 redirecting to the url we want. It works fine: click it and you load a random page. The problem is that each time you click it, the browser assumes you're loading the same page: so if you're on the homepage, then you follow the random link 5 times, then you press back, you'll be taken all the way back to the homepage, with no way to find the random pages you were just looking at. I want to modify this behavior so that users can access previous random pages via the back and forward buttons.
I don't own the website, so I can't just change the redirect code.
Here's what I've tried, all of which has failed.
Predicting what would be redirected to. While somewhat possible, there would be no way to avoid failure in up to .1% of clicks, and it would react very poorly to unexpected events, like a page that's published a day late, let alone a sit structure change.
Loading the 307 page via ajax. The request stops at readystate == 2 and I can't access the location header.
Cancel the click event and instead set location.href = random_link.href. This has no effect - the new page still doesn't go into history.
Have the new page call history.pushState. This successfully adds the page to history, but I can't find a way to distinguish between new pages and ones being opened via the back button, so the history quickly becomes very corrupted.
Keeping my own history in localStorage. As above, I can't tell when the back button is being used.
I'm working on a solution that I'm pretty sure will work, involving loading the page in an iframe over the existing page and using a background process and messaging to work around the fact that content injections from chrome extensions can't access window.parent from within iframes. And using the history API to reflect the current iframe's URL in the address bar, and get the back and forwards buttons to apply to the current iframe where appropriate.
While I'm pretty sure the last solution can be made to work, it's a hideously complex and heavyweight approach to what seems like a simple problem. So I thought I'd ask you guys before I continue: any other ideas?
Have you tried storing the locations in localStorage, then hi-jacking the back button ?
I am sure you know how localStorage works, for hi-jacking the back button you can refer to this : Is there a way to catch the back button event in javascript?
T.

How to capture browser's event by javascript

i want to know is there any way we can know browser's events.. like : clicking on BACK button, FORWARD button, REFRESH button by javascript.
These specific browser events are not available as it would be vulnerable to severe privacy violations. Privacy is something browser vendors hold sacred and a key selling (proverbial) point. All browsers allow you to know is when a user enters or leaves your page for which Kamui pointed out the technical details.
Within the same site, it's possible to achieve some browser event tracking using cookies and javascript. For example track wether users click on a hyperlink and label it as a forward event and when a user leaves the page without clicking on a hyperlink it could be one of:
browser url input
back action
javascript location.href replace
The location.href replace can be tracked as well when you have full control over all javascript, just use a helper method with tracking code instead of directly chaning location.href.
That leaves browser url input and the back action. With cookies and request headers (getting the referrer) it is possible to get close to finding out the forward and back events, though not 100%, but pragmatically, 99% sure is good enough.
Figuring out the refresh event is easy with request headers (referrer), if the current url matches the referrrer, it's a refresh event.
Now I offer no code or definite solution, but I outlined what you could do to track back, forward and refresh events within a single domain context. It won't be a quick and easy way to implement it and as far as I know, there's no framework in existance that reliably tracks browser events or even comes close to what I described above.
A more common/lazy technique to achieve something similar is to create a single page app, for which there are many frameworks available. Just google single page app framework, but thats a pretty heavy solution with other implications that I won't go into now.
You can not capture (for example run some piece of code when user presses Back button) them, however, you can direct your pages in history by using:
history.go
history.back
history.forward
More about JS History object.
As #sarfraz says you cannot capture the back and forward button clicks but you could call
window.onbeforeunload = function(){alert("you just tried to leave the page");};
which should be triggered when either the back/forward/refresh buttons are clicked to perform an action, unfortunately you can't tell if they are going back or forward. Please note don't alert a message it's really annoying when trying to exit a page.
EDIT
you can also do this in jQuery if you have it
$(window).unload( function () { alert("Bye now!"); } );

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