17811 2012-07-18 06:53:25 +0000 Expose history traversal direction 2012-12-07 22:49:05 +0000 1 1 1 Unclassified WHATWG HTML unspecified Other other RESOLVED WORKSFORME http://www.whatwg.org/specs/web-apps/current-work/#traverse-the-history P3 normal Unsorted 1 contributor ian annevk ian mail mike nekr.fabula contributor oldest_to_newest 70092 0 contributor 2012-07-18 06:53:25 +0000 This was was cloned from bug 15366 as part of operation convergence. Originally filed: 2011-12-30 11:21:00 +0000 Original reporter: Anne <annevk@annevk.nl> ================================================================================ #0 Anne 2011-12-30 11:21:40 +0000 -------------------------------------------------------------------------------- E.g. for CSS transitions it would be nice if history traversal direction was known. Especially now there's history.pushState(). You can track this yourself but it would be nicer if it was explicitly exposed. (Feedback from Ben Joffe.) ================================================================================ #1 Ben Joffe 2011-12-30 11:35:00 +0000 -------------------------------------------------------------------------------- Perhaps this could be a property of the event object as an integer (defined the same as the argument that could have been passed to history.go to trigger the navigation). Another reason to want this property: some navigational states may be associated with an xhr request, if the navigation is back then it may be appropriate to display the previous result of that request, but if it is forward it may be appropriate to redo the request. ================================================================================ #2 Ian 'Hixie' Hickson 2012-02-01 00:54:32 +0000 -------------------------------------------------------------------------------- Interesting idea. Sometimes the direction is forward relative to the last state that was active in the document, but backward relative to the last active entry in the session history, what would you do for that? ================================================================================ 73980 1 ian 2012-09-16 03:56:05 +0000 Ben, any feedback on the question in #2 above? 74054 2 ian 2012-09-18 23:03:59 +0000 Anne, without further info from Ben regarding what he wants, I don't know what to do here. 74641 3 mail 2012-09-27 12:27:39 +0000 Hixie: I can't see the scenario that would lead to what you describe in #2, from what I understand the document history delta should always be the same as the browser history delta. Could you please elaborate? 74712 4 ian 2012-09-28 03:41:39 +0000 Ben: Yeah. Consider this case: 1. User opens a.html. 2. User clicks a link to b.html. 3. User clicks a link to b.html#z. 4. User goes back in one step to a.html, by using the drop-down next to the back button. 5. User clicks the forward button. Now b.html gets a forward navigation to its first session history entry, but the last active state of that document was its second session history entry. 74764 5 mail 2012-09-28 09:21:00 +0000 Ah I see, thanks. In that case I guess the value could potentially be defined in two different ways, though I think being defined relative to the document's last history state has several advantages: - If the document relies on this property for animations then it will animate in the correct direction for whatever content is flashed on the page to start with. - Compatibility libraries can provide this property for older browsers, whereas if it's relative to the browser there won't be a way to detect the actual delta. - In your example on step 4, a.html doesn't need to do any history management, no popstate is fired currently (if I understand correctly), which matches the behaviour of a delta of zero not firing a popstate if this is relative to the document. 79399 6 nekr.fabula 2012-12-04 12:17:26 +0000 Hello. I read this conversation and have some opinions about this situation. May be need just define new attribute of History interface, which indicates the current index of history traversal. For example you can define |currentIndex| attribute which is change right before popstate/hashchange event is fired. So, developer can store previous index of history traversal and compare difference with new |currentIndex| and last |currentIndex|. Sorry if I have mistakes in my text. I am not native speaker. 79687 7 ian 2012-12-07 22:49:05 +0000 If you just want to animate from the current state to the new state, it seems that there's no need to use a new feature on History. You already know what state you're currently in, basically by definition. You know what state you're going to. Just animate between them. So I don't understand what this would add. If I'm missing something, please don't hesitate to reopen the bug.