Slick.prototype.progressiveLazyLoad = function()

in assets/js/slick.js [1762:1844]
20 lines of code
4 McCabe index (conditional complexity)

    Slick.prototype.progressiveLazyLoad = function( tryCount ) {

        tryCount = tryCount || 1;

        var _ = this,
            $imgsToLoad = $( 'img[data-lazy]', _.$slider ),
            image,
            imageSource,
            imageSrcSet,
            imageSizes,
            imageToLoad;

        if ( $imgsToLoad.length ) {

            image = $imgsToLoad.first();
            imageSource = image.attr('data-lazy');
            imageSrcSet = image.attr('data-srcset');
            imageSizes  = image.attr('data-sizes') || _.$slider.attr('data-sizes');
            imageToLoad = document.createElement('img');

            imageToLoad.onload = function() {

                if (imageSrcSet) {
                    image
                        .attr('srcset', imageSrcSet );

                    if (imageSizes) {
                        image
                            .attr('sizes', imageSizes );
                    }
                }

                image
                    .attr( 'src', imageSource )
                    .removeAttr('data-lazy data-srcset data-sizes')
                    .removeClass('slick-loading');

                if ( _.options.adaptiveHeight === true ) {
                    _.setPosition();
                }

                _.$slider.trigger('lazyLoaded', [ _, image, imageSource ]);
                _.progressiveLazyLoad();

            };

            imageToLoad.onerror = function() {

                if ( tryCount < 3 ) {

                    /**
                     * try to load the image 3 times,
                     * leave a slight delay so we don't get
                     * servers blocking the request.
                     */
                    setTimeout( function() {
                        _.progressiveLazyLoad( tryCount + 1 );
                    }, 500 );

                } else {

                    image
                        .removeAttr( 'data-lazy' )
                        .removeClass( 'slick-loading' )
                        .addClass( 'slick-lazyload-error' );

                    _.$slider.trigger('lazyLoadError', [ _, image, imageSource ]);

                    _.progressiveLazyLoad();

                }

            };

            imageToLoad.src = imageSource;

        } else {

            _.$slider.trigger('allImagesLoaded', [ _ ]);

        }

    };