我正在执行一个外部脚本,使用<脚本>内<头>。
现在,由于脚本在页面加载之前执行,我不能访问<body>等。我想在文档被“加载”(HTML完全下载并在ram中)后执行一些JavaScript。是否有任何事件,我可以挂钩到当我的脚本执行,这将在页面加载触发?
我正在执行一个外部脚本,使用<脚本>内<头>。
现在,由于脚本在页面加载之前执行,我不能访问<body>等。我想在文档被“加载”(HTML完全下载并在ram中)后执行一些JavaScript。是否有任何事件,我可以挂钩到当我的脚本执行,这将在页面加载触发?
当前回答
$(window).on("load", function(){ ... });
.ready()最适合我。
$(document).ready(function(){ ... });
.load()将工作,但它不会等到页面加载。
jQuery(window).load(function () { ... });
对我不起作用,破坏了下一个内联脚本。我也使用jQuery 3.2.1以及一些其他的jQuery叉子。
隐藏我的网站加载覆盖,我使用以下:
<script>
$(window).on("load", function(){
$('.loading-page').delay(3000).fadeOut(250);
});
</script>
其他回答
如果脚本是在文档的<head>中加载的,那么可以在script标记中使用defer属性。
例子:
<script src="demo_defer.js" defer></script>
从https://developer.mozilla.org:
推迟 此布尔属性被设置为向浏览器指示脚本 意味着在解析文档之后执行,但在解析之前 发射DOMContentLoaded。内 如果src 属性不存在(即对于内联脚本),在这种情况下它会 没有效果。 为实现动态插入脚本使用的类似效果 异步= false。具有defer属性的脚本将在 它们在文档中出现的顺序。
只需定义<body onload=" function ()>,它将在页面加载后被调用。脚本中的代码被function(){}括起来。
我可以通过这段代码捕获页面加载
<script>
console.log("logger saber");
window.onload = (event) => {
console.log('page is fully loaded');
document.getElementById("tafahomNameId_78ec7c44-beab-40de-9326-095f474519f4_$LookupField").value = 1;;
};
</script>
这些解决方案是有效的:
正如注释中提到的,使用defer:
<script src="deferMe.js" defer></script>
or
<body onload="script();">
or
document.onload = function ...
甚至
window.onload = function ...
请注意,最后一个选项是更好的方法,因为它不引人注目,而且被认为更标准。
比较
在下面的片段中,我收集选择的方法并显示它们的序列。讲话
the document.onload (X) is not supported by any modern browser (event is never fired) if you use <body onload="bodyOnLoad()"> (F) and at the same time window.onload (E) then only first one will be executed (because it override second one) event handler given in <body onload="..."> (F) is wrapped by additional onload function document.onreadystatechange (D) not override document .addEventListener('readystatechange'...) (C) probably cecasue onXYZevent-like methods are independent than addEventListener queues (which allows add multiple listeners). Probably nothing happens between execution this two handlers. all scripts write their timestamp in console - but scripts which also have access to div write their timestamps also in body (click "Full Page" link after script execution to see it). solutions readystatechange (C,D) are executed multiple times by browser but for different document states: loading - the document is loading (no fired in snippet) interactive - the document is parsed, fired before DOMContentLoaded complete - the document and resources are loaded, fired before body/window onload
<html> <head> <script> // solution A console.log(`[timestamp: ${Date.now()}] A: Head script`); // solution B document.addEventListener("DOMContentLoaded", () => { print(`[timestamp: ${Date.now()}] B: DOMContentLoaded`); }); // solution C document.addEventListener('readystatechange', () => { print(`[timestamp: ${Date.now()}] C: ReadyState: ${document.readyState}`); }); // solution D document.onreadystatechange = s=> {print(`[timestamp: ${Date.now()}] D: document.onreadystatechange ReadyState: ${document.readyState}`)}; // solution E (never executed) window.onload = () => { print(`E: <body onload="..."> override this handler`); }; // solution F function bodyOnLoad() { print(`[timestamp: ${Date.now()}] F: <body onload='...'>`); infoAboutOnLoad(); // additional info } // solution X document.onload = () => {print(`document.onload is never fired`)}; // HELPERS function print(txt) { console.log(txt); if(mydiv) mydiv.innerHTML += txt.replace('<','<').replace('>','>') + '<br>'; } function infoAboutOnLoad() { console.log("window.onload (after override):", (''+document.body.onload).replace(/\s+/g,' ')); console.log(`body.onload==window.onload --> ${document.body.onload==window.onload}`); } console.log("window.onload (before override):", (''+document.body.onload).replace(/\s+/g,' ')); </script> </head> <body onload="bodyOnLoad()"> <div id="mydiv"></div> <!-- this script must te at the bottom of <body> --> <script> // solution G print(`[timestamp: ${Date.now()}] G: <body> bottom script`); </script> </body> </html>