swiper/src/components/core/loop/loopCreate.js

Most modern mobile touch slider and framework with hardware accelerated transitions

import { document } from 'ssr-window';
import $ from '../../../utils/dom';

export default function () {
  const swiper = this;
  const { params, $wrapperEl } = swiper;
  // Remove duplicated slides
  $wrapperEl.children(`.${params.slideClass}.${params.slideDuplicateClass}`).remove();

  let slides = $wrapperEl.children(`.${params.slideClass}`);

  if (params.loopFillGroupWithBlank) {
    const blankSlidesNum = params.slidesPerGroup - (slides.length % params.slidesPerGroup);
    if (blankSlidesNum !== params.slidesPerGroup) {
      for (let i = 0; i < blankSlidesNum; i += 1) {
        const blankNode = $(document.createElement('div')).addClass(`${params.slideClass} ${params.slideBlankClass}`);
        $wrapperEl.append(blankNode);
      }
      slides = $wrapperEl.children(`.${params.slideClass}`);
    }
  }

  if (params.slidesPerView === 'auto' && !params.loopedSlides) params.loopedSlides = slides.length;

  swiper.loopedSlides = Math.ceil(parseFloat(params.loopedSlides || params.slidesPerView, 10));
  swiper.loopedSlides += params.loopAdditionalSlides;
  if (swiper.loopedSlides > slides.length) {
    swiper.loopedSlides = slides.length;
  }

  const prependSlides = [];
  const appendSlides = [];
  slides.each((index, el) => {
    const slide = $(el);
    if (index < swiper.loopedSlides) appendSlides.push(el);
    if (index < slides.length && index >= slides.length - swiper.loopedSlides) prependSlides.push(el);
    slide.attr('data-swiper-slide-index', index);
  });
  for (let i = 0; i < appendSlides.length; i += 1) {
    $wrapperEl.append($(appendSlides[i].cloneNode(true)).addClass(params.slideDuplicateClass));
  }
  for (let i = prependSlides.length - 1; i >= 0; i -= 1) {
    $wrapperEl.prepend($(prependSlides[i].cloneNode(true)).addClass(params.slideDuplicateClass));
  }
}