Load a JavaScript File On The Fly

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Load a JavaScript file on demand and execute dependent functions.

function loadFile() {
    // Create a script tag, set its source
    var scriptTag = document.createElement("script"),
        filePath = "/path/to/file.js";

    // And listen to it
    scriptTag.onload = function(loadEvent) {
        // This function is an event handler of the script tag
        handleEvent();
    }

    // Make sure this file actually loads instead of a cached version
    // Add a timestamp onto the URL (i.e. file.js?bust=12345678)
    var cacheBuster = "";

    cacheBuster = "?bust=" + new Date().getTime();

    // Set the type of file and where it can be found
    scriptTag.type = "text/javascript";
    scriptTag.src = filePath + cacheBuster;

    // Finally add it to the <head>
    document.getElementsByTagName("head")[0].appendChild(scriptTag);
}

function handleEvent() {
    console.log('The file has been loaded. Do something else.');
    // More code here
}

// Usage
loadFile();

Find more JavaScript tutorials, code snippets and samples here or more jQuery tutorials, code snippets and samples here.

Find more JavaScript tutorials, code snippets and samples here or more jQuery tutorials, code snippets and samples here.

👋 Added by Ciprian on Thursday, January 11, 2018 in Blog, JavaScript. Last modified on Friday, January 5, 2018.

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