Call Javascript Function After Script Is Loaded

In the world of web development, knowing how to ensure a JavaScript function is called only after a script has been fully loaded can be crucial for creating efficient and smooth-running websites. By using this technique, you can prevent potential errors and ensure that your code runs seamlessly without interruptions.

One common method to achieve this is by leveraging the `onload` event handler in JavaScript. When a script is loaded onto a webpage, the `onload` event is triggered once the script has completely loaded. This provides an excellent opportunity to call your desired JavaScript function without worrying about timing issues.

To implement this method, you can attach an `onload` event listener to the `` tag that references the external JavaScript file you want to load. Here's an example to illustrate this concept:

const scriptElement = document.createElement('script');
scriptElement.src = 'path/to/your/script.js';

// Define the function to be called after the script is fully loaded
function myFunction() {
    // Your code here
}

// Attach the onload event listener
scriptElement.onload = myFunction;

// Append the script element to the document
document.body.appendChild(scriptElement);

In this snippet, a new `` element is dynamically created and configured with the URL to your external JavaScript file. The `myFunction` function is then defined as the function you want to call after the script has finished loading. By setting the `onload` property of the script element to `myFunction`, you ensure that `myFunction` is executed only after the external script has been fully loaded.

Another approach to achieve the same goal is by using the `defer` attribute in the `` tag. When a script tag includes the `defer` attribute, it indicates that the script should be executed after the HTML document has been parsed, but before the `DOMContentLoaded` event is fired. This allows you to control the execution order of your scripts more effectively.

Here's an example of how you can use the `defer` attribute in your HTML code:

function myFunction() {
        // Your code here
    }

    myFunction();

In this example, the `myFunction` is directly called after the `` tag that links to your external JavaScript file with the `defer` attribute. This ensures that `myFunction` will be executed only after the script has been loaded and parsed by the browser.

By implementing these techniques in your web development projects, you can control the flow of your JavaScript functions and scripts effectively, ensuring that your code runs smoothly and efficiently. Remember to test your code thoroughly to confirm that the desired function is called only after the script has been loaded successfully.