Sample Server Side Script (Revslider Full Height Slider)

if (document.querySelector('.rev_slider_wrapper') !== null){
    // Get the first slide element
    var slide = document.querySelector('rs-slide img:first-child');

    // Clone first slide
    var clone = slide.cloneNode(true);

    // Create a wrapper
    var cloneWrapper = document.createElement('div');

    // Add class name to the wrapper
    cloneWrapper.classList.add('pseudo-slide-wrapper');

    // Add class name to the cloned slide
    clone.classList.add('pseudo-slide');

    // Add the wrapper to DOM
    cloneWrapper.append(clone);

    // Add the slide to the wrapper
    document.querySelector('.rev_slider_wrapper').prepend(cloneWrapper);
}