jquery.cycle2.progressive.js

/*! progressive loader plugin for Cycle2;  version: 20130315 */
(function($) {
"use strict";

$.extend($.fn.cycle.defaults, {
    progressive: false
});

$(document).on( 'cycle-pre-initialize', function( e, opts ) {
    if ( !opts.progressive )
        return;

    var API = opts.API;
    var nextFn = API.next;
    var prevFn = API.prev;
    var prepareTxFn = API.prepareTx;
    var type = $.type( opts.progressive );
    var slides, scriptEl;

    if ( type == 'array' ) {
        slides = opts.progressive;
    }
    else if ($.isFunction( opts.progressive ) ) {
        slides = opts.progressive( opts );
    }
    else if ( type == 'string' ) {
        scriptEl = $( opts.progressive );
        slides = $.trim( scriptEl.html() );
        if ( !slides )
            return;
        // is it json array?
        if ( /^(\[)/.test( slides ) ) {
            try {
                slides = $.parseJSON( slides );
            }
            catch(err) {
                API.log( 'error parsing progressive slides', err );
                return;
            }
        }
        else {
            // plain text, split on delimeter
            slides = slides.split( new RegExp( scriptEl.data('cycle-split') || '\n') );
            
            // #95; look for empty slide
            if ( ! slides[ slides.length - 1 ] )
                slides.pop();
        }
    }



    if ( prepareTxFn ) {
        API.prepareTx = function( manual, fwd ) {
            var index, slide;

            if ( manual || slides.length === 0 ) {
                prepareTxFn.apply( opts.API, [ manual, fwd ] );
                return;
            }

            if ( fwd && opts.currSlide == ( opts.slideCount-1) ) {
                slide = slides[ 0 ];
                slides = slides.slice( 1 );
                opts.container.one('cycle-slide-added', function(e, opts ) {
                    setTimeout(function() {
                        opts.API.advanceSlide( 1 );
                    },50);
                });
                opts.API.add( slide );
            }
            else if ( !fwd && opts.currSlide === 0 ) {
                index = slides.length-1;
                slide = slides[ index ];
                slides = slides.slice( 0, index );
                opts.container.one('cycle-slide-added', function(e, opts ) {
                    setTimeout(function() {
                        opts.currSlide = 1;
                        opts.API.advanceSlide( -1 );
                    },50);
                });
                opts.API.add( slide, true );
            }
            else {
                prepareTxFn.apply( opts.API, [ manual, fwd ] );
            }
        };
    }

    if ( nextFn ) {
        API.next = function() {
            var opts = this.opts();
            if ( slides.length && opts.currSlide == ( opts.slideCount - 1 ) ) {
                var slide = slides[ 0 ];
                slides = slides.slice( 1 );
                opts.container.one('cycle-slide-added', function(e, opts ) {
                    nextFn.apply( opts.API );
                    opts.container.removeClass('cycle-loading');
                });
                opts.container.addClass('cycle-loading');
                opts.API.add( slide );
            }
            else {
                nextFn.apply( opts.API );    
            }
        };
    }
    
    if ( prevFn ) {
        API.prev = function() {
            var opts = this.opts();
            if ( slides.length && opts.currSlide === 0 ) {
                var index = slides.length-1;
                var slide = slides[ index ];
                slides = slides.slice( 0, index );
                opts.container.one('cycle-slide-added', function(e, opts ) {
                    opts.currSlide = 1;
                    opts.API.advanceSlide( -1 );
                    opts.container.removeClass('cycle-loading');
                });
                opts.container.addClass('cycle-loading');
                opts.API.add( slide, true );
            }
            else {
                prevFn.apply( opts.API );
            }
        };
    }
});

})(jQuery);