Slick.prototype.lazyLoad = function()

in slick/slick.js [1347:1409]
31 lines of code
10 McCabe index (conditional complexity)

    Slick.prototype.lazyLoad = function() {

        var _ = this,
            loadRange, cloneRange, rangeStart, rangeEnd;

        function loadImages(imagesScope) {
            $('img[data-lazy]', imagesScope).each(function() {

                var image = $(this),
                    imageSource = $(this).attr('data-lazy'),
                    imageToLoad = document.createElement('img');

                imageToLoad.onload = function() {
                    image
                        .animate({ opacity: 0 }, 100, function() {
                            image
                                .attr('src', imageSource)
                                .animate({ opacity: 1 }, 200, function() {
                                    image
                                        .removeAttr('data-lazy')
                                        .removeClass('slick-loading');
                                });
                        });
                };

                imageToLoad.src = imageSource;

            });
        }

        if (_.options.centerMode === true) {
            if (_.options.infinite === true) {
                rangeStart = _.currentSlide + (_.options.slidesToShow / 2 + 1);
                rangeEnd = rangeStart + _.options.slidesToShow + 2;
            } else {
                rangeStart = Math.max(0, _.currentSlide - (_.options.slidesToShow / 2 + 1));
                rangeEnd = 2 + (_.options.slidesToShow / 2 + 1) + _.currentSlide;
            }
        } else {
            rangeStart = _.options.infinite ? _.options.slidesToShow + _.currentSlide : _.currentSlide;
            rangeEnd = rangeStart + _.options.slidesToShow;
            if (_.options.fade === true) {
                if (rangeStart > 0) rangeStart--;
                if (rangeEnd <= _.slideCount) rangeEnd++;
            }
        }

        loadRange = _.$slider.find('.slick-slide').slice(rangeStart, rangeEnd);
        loadImages(loadRange);

        if (_.slideCount <= _.options.slidesToShow) {
            cloneRange = _.$slider.find('.slick-slide');
            loadImages(cloneRange);
        } else
        if (_.currentSlide >= _.slideCount - _.options.slidesToShow) {
            cloneRange = _.$slider.find('.slick-cloned').slice(0, _.options.slidesToShow);
            loadImages(cloneRange);
        } else if (_.currentSlide === 0) {
            cloneRange = _.$slider.find('.slick-cloned').slice(_.options.slidesToShow * -1);
            loadImages(cloneRange);
        }

    };