你能在js中获得以前的历史状态对象吗？ [英] Can you get the previous history state object in js?

问题描述

当我按下向后或向前按钮并且popstate事件触发时，我可以获得前一状态的状态对象吗？因为不是e.state提供的状态对象，而是我刚刚退回/转发的状态对象？

When I hit the backwards or forwards button and the popstate event fires, can I get the state object of the previous state? As in not the state object provided by e.state but the one I just back/forwarded away from?

或者，我可以检测它是按下的后退还是前进按钮？

Alternatively, can I detect whether it was the back or forwards button that was pressed?

我需要这个，因为我有多个子系统都需要同时使用js历史记录，我当然可以在推送时保存所有子系统的状态但是然后，当我弹出时，我必须将状态恢复到所有这些状态，这是不希望的，因为它重置了我不需要的对象。例如

I need this since I have multiple subsystems that all need to use the js history at the same time, I could save the state of all of them when pushing of course but then, when I pop I have to restore the state to all of them too which is undesired as it resets objects that I don't need to. For example

state 1 = {a:1, b:1, c:1}
push a = 2
state 2 = {a:2, b:1, c:1}
hit back button, popstate fires state 1 to me
restart a with 1, b with 1, c with 1 while I only need to restart a

另类幻想解决方案

....
hit back button, popstate fires state 1 to me
I also get state 2 (the one I just moved away from) through some black magic
do a differential comparison between the 2 states, find out that I only need to modify a
restart a with 1

编辑：哦，为了澄清，没有简单的方法可以检查页面上当前的状态a，b和c（因为它比abc和123更复杂一些） ）

oh also, to clarify, there is no easy way to check what state a, b and c currently are on the page (since its a bit more complicated than abc and 123)

推荐答案

onpopstate 在状态更改后触发，因此无法获取起源状态，但你可以反过来做，比如拥有状态和ind的副本当前状态的icator，并手动更新 onpopstate 中的副本。

onpopstate is fired after the state change so you cannot get the originating state, but you can do it the other way around, like having a copy of the states and indicator of current state, and update your copy in the onpopstate manually.

这篇关于你能在js中获得以前的历史状态对象吗？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！