How can I enable garbage collection for an externally loaded JavaScript file?

Other Questions JavaScript
1

If I have a script loader like the following code:

function scriptLoader(source, onSuccess, onError) {
    let scriptElement = document.head.appendChild(document.createElement('script'));
    scriptElement.type = 'text/javascript';
    scriptElement.src = source;
    scriptElement.onload = function() {
        onSuccess();
        scriptElement.onload = null; // Is this necessary?
        scriptElement = null; // Should I do this as well?
    }
    scriptElement.onerror = onError;
}

I am wondering if setting scriptElement.onload = null helps the garbage collector free up memory.

2

To achieve efficient memory management when loading JavaScript files dynamically, managing event handlers and references effectively is crucial. The practice of setting scriptElement.onload = null; serves an important purpose: it clears the reference to the handler function, enabling the garbage collector to free up the associated memory. This action prevents any potential memory leaks that could arise if the event handlers remain attached to elements no longer in use.

Similarly, setting scriptElement = null; informs the garbage collector that the script element itself is no longer needed. Doing this allows the resources occupied by the script element to be reclaimed once it goes out of scope.

A novel aspect to consider is managing scalability across multiple scripts. If you plan to load various scripts, having a more robust cleanup pattern aids in ensuring your script loader remains scalable.

function scriptLoader(source, onSuccess, onError) {
    const scriptElement = document.createElement('script');
    scriptElement.type = 'text/javascript';
    scriptElement.src = source;
    addListeners(scriptElement, onSuccess, onError);
    document.head.appendChild(scriptElement);
}

function addListeners(scriptElement, onSuccess, onError) {
    scriptElement.onload = () => {
        onSuccess();
        cleanup(scriptElement);
    };
    scriptElement.onerror = () => {
        onError();
        cleanup(scriptElement);
    };
}

function cleanup(scriptElement) {
    scriptElement.onload = null;
    scriptElement.onerror = null;
    if (scriptElement.parentNode) {
        scriptElement.parentNode.removeChild(scriptElement);
    }
}

In this approach, I've introduced a function addListeners() to attach the event handlers, which helps keep the code cleaner and focused on specific tasks, thus enhancing readability and maintainability. Additionally, the cleanup not only nullifies the handlers but also removes the script element from the DOM, further aiding memory management.