如何检查URL是否在JavaScript中发生了变化?例如,像GitHub这样使用AJAX的网站,会在#符号后附加页面信息,以创建唯一的URL,而无需重新加载页面。检测该URL是否发生变化的最佳方法是什么?

是否再次调用onload事件? 是否有URL的事件处理程序? 或者必须每秒钟检查URL以检测更改?


当前回答

下面的答案来自这里(使用旧的javascript语法(没有箭头函数,支持IE 10+)): https://stackoverflow.com/a/52809105/9168962

(function() {
  if (typeof window.CustomEvent === "function") return false; // If not IE
  function CustomEvent(event, params) {
    params = params || {bubbles: false, cancelable: false, detail: null};
    var evt = document.createEvent("CustomEvent");
    evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
    return evt;
  }
  window.CustomEvent = CustomEvent;
})();

(function() {
  history.pushState = function (f) {
    return function pushState() {
      var ret = f.apply(this, arguments);
      window.dispatchEvent(new CustomEvent("pushState"));
      window.dispatchEvent(new CustomEvent("locationchange"));
      return ret;
    };
  }(history.pushState);
  history.replaceState = function (f) {
    return function replaceState() {
      var ret = f.apply(this, arguments);
      window.dispatchEvent(new CustomEvent("replaceState"));
      window.dispatchEvent(new CustomEvent("locationchange"));
      return ret;
    };
  }(history.replaceState);
  window.addEventListener("popstate", function() {
    window.dispatchEvent(new CustomEvent("locationchange"));
  });
})();

其他回答

要收听url更改,请参见以下内容:

window.onpopstate = function(event) {
  console.log("location: " + document.location + ", state: " + JSON.stringify(event.state));
};

如果您打算在某些特定条件后停止/删除侦听器,请使用此样式。

window.addEventListener('popstate', function(e) {
   console.log('url changed')
});

下面的答案来自这里(使用旧的javascript语法(没有箭头函数,支持IE 10+)): https://stackoverflow.com/a/52809105/9168962

(function() {
  if (typeof window.CustomEvent === "function") return false; // If not IE
  function CustomEvent(event, params) {
    params = params || {bubbles: false, cancelable: false, detail: null};
    var evt = document.createEvent("CustomEvent");
    evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
    return evt;
  }
  window.CustomEvent = CustomEvent;
})();

(function() {
  history.pushState = function (f) {
    return function pushState() {
      var ret = f.apply(this, arguments);
      window.dispatchEvent(new CustomEvent("pushState"));
      window.dispatchEvent(new CustomEvent("locationchange"));
      return ret;
    };
  }(history.pushState);
  history.replaceState = function (f) {
    return function replaceState() {
      var ret = f.apply(this, arguments);
      window.dispatchEvent(new CustomEvent("replaceState"));
      window.dispatchEvent(new CustomEvent("locationchange"));
      return ret;
    };
  }(history.replaceState);
  window.addEventListener("popstate", function() {
    window.dispatchEvent(new CustomEvent("locationchange"));
  });
})();

如果没有窗口事件为您工作(在我的例子中不是这样),您还可以使用MutationObserver来查看根元素(非递归地)。

// capture the location at page load
let currentLocation = document.location.href;

const observer = new MutationObserver((mutationList) => {
  if (currentLocation !== document.location.href) {
    // location changed!
    currentLocation = document.location.href;

    // (do your event logic here)
  }
});

observer.observe(
  document.getElementById('root'),
  {
    childList: true,

    // important for performance
    subtree: false
  });

这可能并不总是可行的,但通常情况下,如果URL更改,根元素的内容也会更改。

我没有进行概要分析,但从理论上讲,这比计时器的开销要小,因为Observer模式通常是实现的,因此当发生更改时,它只是通过订阅进行循环。我们在这里只添加了一个订阅。另一方面,计时器必须非常频繁地检查,以确保在URL更改后立即触发事件。

此外,这比计时器更可靠,因为它消除了计时问题。

适用于Chrome 102+ (2022-05-24)

navigation.addEventListener("navigate", e => {
  console.log(`navigate ->`,e.destination.url)
});

消防引用巫术崇拜者

window.onhashchange = function() { 
     //code  
}

window.onpopstate = function() { 
     //code  
}

or

window.addEventListener('hashchange', function() { 
  //code  
});

window.addEventListener('popstate', function() { 
  //code  
});

与jQuery

$(window).bind('hashchange', function() {
     //code
});

$(window).bind('popstate', function() {
     //code
});