Preload script file

Question

There are numerous plug-ins to preload images, but is there a way to preload javascript? My application uses a big js file and it take about 5 seconds or so to load before t

Answer 1

This is the current standard:

...

or you can just append it

var preloadLink = document.createElement("link");
preloadLink.href = "script-to-preload.js";
preloadLink.rel = "preload";
preloadLink.as = "script";
document.head.appendChild(preloadLink);

then when you want to use it:

or

var preloadedScript = document.createElement("script");
preloadedScript.src= "/js/script-to-preload.js";
document.head.appendChild(preloadedScript);

to check if your browser is compatible with it just use this snippet of code: https://gist.github.com/yoavweiss/8490dabb3e0aa112fc74

in case it isn't supported you can use the deprecated prefetch instead of preload

source:

https://w3c.github.io/preload/#x2.link-type-preload

https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content

https://developer.mozilla.org/en-US/docs/Web/API/DOMTokenList/supports