javascript - 如何在 Windows popstate 上显示当前(不是以前)状态

Question

我正在抓取 popstate，需要根据历史堆栈中的 current 和 originalEvent 做各种事情。但是，我不知道如何获取当前状态进行比较，但 originalEvent 有效。这是我的 JS 代码。第一个 IF 语句引发了 e.state.id 未定义的异常......

$(window).on("popstate", function(e) {
        //check and compare current state
        if (e.state.id == 'something') {  // throws an exception
            *do something*
        } else if (e.originalEvent.state !== null) { //previous state exists?
            *do something*
        } else { //no previous state
            *do something*
        }
    });

仅供引用，推送状态设置为:

history.pushState({id: 'view'}, '', '/view');

Answer 1

扩展历史对象
这是我的来源，您可以从 https://gist.github.com/HasanDelibas/12050fc59d675181ea973d21f882081a 查看完整资源

该库包含:

history.states -> 获取状态列表

history.stateIndex -> 当前状态索引

"historyChange"事件 -> 检测历史变化 (from,to,side="back"|"forward")

重要的! state必须是 history.pushState( **state**, ...) 的对象

(function(){
  let stateSymbol = "__state__index__";
  history.stateIndex =-1;
  history.states=[];
  let pushState = history.pushState;
  function add(data,title,url){
    if(data==null) data={};
    if(typeof data!="object") data={data:data};
    data[stateSymbol] = (history.stateIndex+1);
    history.states.splice(history.stateIndex+1,0,[data,title,url])
    history.states.splice(history.stateIndex+2)
    history.stateIndex++;
  }
  history.pushState =function(data,title,url=null){
    add(data,title,url);
    pushState.bind(history)(data,title,url);
  }
  addEventListener("popstate",function(e){
    var eventObject= {};
    var newStateIndex =  e.state!=null ? e.state[stateSymbol] : -1;
    eventObject.from = history.states[history.stateIndex];
    eventObject.to   = newStateIndex>-1 ? history.states[newStateIndex] : null;
    eventObject.side = history.stateIndex>newStateIndex ? "back" : "forward"; 
    if( newStateIndex > -1 && !(newStateIndex in history.states) ){
      add(history.state,"",window.location.href);
    }
    window.dispatchEvent(new CustomEvent("historyChange", {detail: eventObject} ))
    history.stateIndex = e.state!=null ? e.state[stateSymbol] : -1;
  });
})();

现在您可以使用 history.states 获取所有状态目的，
并使用 addEventListener("popstate",function(e)) 检测历史变化
使用

/**
  * @param e.detail.from [data,title,url]
  * @param e.detail.to   [data,title,url]
  * @param e.detail.side "back" | "forward"
  */
addEventListener("historyChange",function(e){
  var from = e.detail.from; // [ data , title , url ]
  var to   = e.detail.to;   // [ data , title , url ]
  var side = e.detail.side; // "back" | "forward"
  console.log( `You changed history. Side is ${e.detail.side}.\nFrom:${e.detail.from[2]}\nTo:${e.detail.to[2]}`)
})


history.pushState("1", "DENEME-TEST" ,"?1");
history.pushState("2", "DENEME-TEST" ,"?2");
// list of history states
console.log( history.states )
/*
[
  [ {...} ,  "DENEME-TEST" ,"?1" ]
  [ {...} ,  "DENEME-TEST" ,"?2" ]
]
*/
// get history current state index
console.log( history.stateIndex )
/*
1
*/