jQuery分页插件

/**
 * 分页插件
 * Created by ck on 2017/4/17.
 */
;(function ($, window, document, undefined) {

    if ($.fn.pager) {
        console.error('可能与其他插件冲突');
    }
    var options = {};
    var leftCount, rightCount, threshold;

    /**
     * @param args
     * @constructor
     */
    var Pager = function (args) {
        var defaults = {
            pageSize: 10,
            aroundCount: 1,
            leftCount: 1,
            rightCount: 1
        };
        this.pageRange = [];

        $.extend(options, defaults, args);
        var centerCount = options.aroundCount * 2 + 1;
        leftCount = options.leftCount || centerCount;
        rightCount = options.rightCount || centerCount;
        threshold = leftCount + centerCount + rightCount;  // 阈值
    };
    Pager.prototype = {
        reset: function (args) {
            options = {};
            $.extend(options, defaults, args);
            var centerCount = options.aroundCount * 2 + 1;
            leftCount = options.leftCount || centerCount;
            rightCount = options.rightCount || centerCount;
            threshold = leftCount + centerCount + rightCount;  // 阈值
        },
        update: function (totalCount, currentPage) {
            this.pageRange = [];
            if (!totalCount || !totalCount) return this;
            var i = 1;
            var pageCount = parseInt(totalCount / options.pageSize);
            totalCount % options.pageSize > 0 && pageCount++;
            this.pageCount = pageCount;
            this.currentPage = Math.max(1, Math.min(currentPage, pageCount));
            if (pageCount <= threshold) {
                for (i = 1; i <= pageCount; i++) {
                    this.pageRange.push(i);
                }
            } else {
                var leftPage = currentPage - options.aroundCount;
                var rightPage = currentPage + options.aroundCount;

                if (leftPage - options.leftCount <= 1) {  // 与左侧有交集
                    rightPage = Math.max(rightPage, options.leftCount);
                    for (i = 1; i <= rightPage; i++) {
                        this.pageRange.push(i);
                    }
                    this.pageRange.push(null);
                    for (i = pageCount - options.rightCount + 1; i <= pageCount; i++) {
                        this.pageRange.push(i);
                    }
                } else if (pageCount - rightPage <= options.rightCount) {  // 与右侧有交集
                    for (i = 1; i <= options.leftCount; i++) {
                        this.pageRange.push(i);
                    }
                    this.pageRange.push(null);
                    leftPage = Math.min(leftPage, pageCount - options.rightCount + 1);
                    for (i = leftPage; i <= pageCount; i++) {
                        this.pageRange.push(i);
                    }
                } else {  // 居中
                    for (i = 1; i <= options.leftCount; i++) {
                        this.pageRange.push(i);
                    }
                    this.pageRange.push(null);
                    for (i = leftPage; i <= rightPage; i++) {
                        this.pageRange.push(i);
                    }
                    this.pageRange.push(null);
                    for (i = pageCount - options.rightCount + 1; i <= pageCount; i++) {
                        this.pageRange.push(i);
                    }
                }
            }
            return this;
        }
    };

    var pager = null;
    var $element, $pagerWrapper, $pagerList, $pagerJumper;
    var updateHtml = function (totalCount, currentPage) {
        if (totalCount == 0) {
            $pagerWrapper.hide();
            return false;
        } else {
            $pagerWrapper.show();
        }
        var pageRange = pager.update(totalCount, currentPage).pageRange;
        currentPage = pager.currentPage;
        var htmlArray = [];
        if (currentPage == 1) {  // 如果当前页面是第一页
            htmlArray.push('
‹
');
        } else {
            htmlArray.push('
‹
');
        }
        for (var i = 0; i < pageRange.length; i++) {
            if (pageRange[i] == null) {
                htmlArray.push('
...
');
            } else if (pageRange[i] == currentPage) {
                htmlArray.push('
' + pageRange[i] + '
');
            } else {
                htmlArray.push('
' + pageRange[i] + '
');
            }
        }
        if (currentPage === pager.pageCount) {  // 如果当前页面是最后一页
            htmlArray.push('
›
');
        } else {
            htmlArray.push('
›
');
        }
        $pagerList.html(htmlArray.join(''));
        $pagerWrapper.show();
    };

    // 回调
    var callbacks = {
        onChange: function (targetPage) {
        }
    };
    // 直接调用
    var method = {
        update: function (args) {
            updateHtml(args[0], args[1]);
        }
    };

    $.fn.pager = function () {
        if (!arguments[0]) {
            console.error('error arguments');
            return false;
        }
        if (arguments[0] === 'method') {
            // 执行方法
            if (!pager) {
                console.error('pager must be initialized');
                return false;
            }
            if (arguments.length < 3) {
                console.error('error arguments');
                return false;
            }
            method[arguments[1]](arguments[2]);
        } else {
            // 初始化控件
            var options = arguments[0];
            $pagerWrapper = $('
 ');
            $pagerList = $('
 
');
            $pagerJumper = $('跳转到GO');
            $(this).append($pagerWrapper.append($pagerList).append($pagerJumper));
            $element = $pagerWrapper;
            pager = new Pager(options);
            options.onChange && (callbacks.onChange = options.onChange);

            $pagerList.on('click', 'li', function () {
                var $ele = $(this);
                if ($ele.hasClass('disabled')) {
                    return false;
                }
                if ($ele.hasClass('pager-num')) {
                    callbacks.onChange(parseInt($(this).text()));
                } else if ($ele.hasClass('pager-prev')) {
                    callbacks.onChange(pager.currentPage - 1);
                } else if ($ele.hasClass('pager-next')) {
                    callbacks.onChange(pager.currentPage + 1);
                }
            });
            var $input = $pagerJumper.children('input');
            $pagerJumper.children('button').click(function () {
                var targetPage = parseInt($input.val());
                if (!targetPage || targetPage < 1) {
                    console.error('请输入正确的页码');
                    return false;
                }
                callbacks.onChange(targetPage);
            });
        }
        return this;
    };


})(jQuery, window, document);