jQuery Pagination插件 - 无法在第一页上单击“下一步”

时间:2017-07-02 12:50:52

标签: javascript jquery pagination

这是关于以下jQuery分页代码:https://github.com/gbirke/jquery_pagination/blob/master/src/jquery.pagination.js

已对原始代码进行了一些自定义,this is a related post对所做的更改进行了自定义。

以下是更新后的代码:https://jsfiddle.net/a6gx5z2o/13/

/**
 * This jQuery plugin displays pagination links inside the selected elements.
 * 
 * This plugin needs at least jQuery 1.4.2
 *
 * @author Gabriel Birke (birke *at* d-scribe *dot* de)
 * @version 2.2
 * @param {int} maxentries Number of entries to paginate
 * @param {Object} opts Several options (see README for documentation)
 * @return {Object} jQuery Object
 */
 (function($){
    /**
     * @class Class for calculating pagination values
     */
    $.PaginationCalculator = function(maxentries, opts) {
        this.maxentries = maxentries;
        this.opts = opts;
    };

    $.extend($.PaginationCalculator.prototype, {
        /**
         * Calculate the maximum number of pages
         * @method
         * @returns {Number}
         */
        numPages:function() {
            return Math.ceil(this.maxentries/this.opts.items_per_page);
        },
        /**
         * Calculate start and end point of pagination links depending on 
         * current_page and num_display_entries.
         * @returns {Array}
         */
        getInterval:function(current_page)  {
            var ne_half = Math.floor(this.opts.num_display_entries/2);
            var np = this.numPages();
            var upper_limit = np - this.opts.num_display_entries;
            var start = current_page > ne_half ? Math.max( Math.min(current_page - ne_half, upper_limit), 0 ) : 0;
            var end = current_page > ne_half?Math.min(current_page+ne_half + (this.opts.num_display_entries % 2), np):Math.min(this.opts.num_display_entries, np);
      return {start:start, end:end};
        }
    });

    // Initialize jQuery object container for pagination renderers
    $.PaginationRenderers = {};

    /**
     * @class Default renderer for rendering pagination links
     */
    $.PaginationRenderers.defaultRenderer = function(maxentries, opts) {
        this.maxentries = maxentries;
        this.opts = opts;
        this.pc = new $.PaginationCalculator(maxentries, opts);
    };
    $.extend($.PaginationRenderers.defaultRenderer.prototype, {
        /**
         * Helper function for generating a single link (or a span tag if it's the current page)
         * @param {Number} page_id The page id for the new item
         * @param {Number} current_page 
         * @param {Object} appendopts Options for the new item: text and classes
         * @returns {jQuery} jQuery object containing the link
         */
        createLink:function(page_id, current_page, appendopts){
            var lnk, np = this.pc.numPages();
            page_id = page_id<0?0:(page_id<np?page_id:np-1); // Normalize page id to sane value
            appendopts = $.extend({text:page_id+1, classes:""}, appendopts||{});
            var weekamount;
            weekamount = Math.ceil(appendopts.text / 7) * 7;
            weekdaysamount = weekamount - 7;
            if(appendopts.text > 7) {
                appendopts.text = appendopts.text - weekdaysamount;
            }
            if(page_id == current_page){
                lnk = $("<span class='current'>" + appendopts.text + "</span>");
            }
            else
            {
                lnk = $("<a>" + appendopts.text + "</a>")
                .attr('href', this.opts.link_to.replace(/__id__/,page_id));
            }
            if(appendopts.classes){ lnk.addClass(appendopts.classes); }
            if(appendopts.rel){ lnk.attr('rel', appendopts.rel); }
            lnk.addClass('page' + page_id);
            lnk.data('page_id', page_id);
            return lnk;
        },
        // Generate a range of numeric links 
        appendRange:function(container, current_page, start, end, opts) {
            var i;
            for(i=start; i<end; i++) {
                this.createLink(i, current_page, opts).appendTo(container);
            }
        },
        getLinks:function(current_page, eventHandler) {
            var begin, end,
                interval = this.pc.getInterval(current_page),
                np = this.pc.numPages(),
                fragment = $("<div class='pagination'></div>");

            // Generate "Previous"-Link

            currentPrevPageCalc = Math.ceil(current_page / 7) * 7;
            currentPrevPage = currentPrevPageCalc - 14;
            fragment.append(this.createLink(currentPrevPage, current_page, {text:this.opts.prev_text, classes:"prev",rel:"prev"}));

            // Generate starting points
            if (interval.start > 0 && this.opts.num_edge_entries > 0)
            {
                end = Math.min(this.opts.num_edge_entries, interval.start);
                this.appendRange(fragment, current_page, 0, end, {classes:'sp'});
                if(this.opts.num_edge_entries < interval.start && this.opts.ellipse_text)
                {
                    $("<span>"+this.opts.ellipse_text+"</span>").appendTo(fragment);
                }
            }
            // Generate interval links
            this.appendRange(fragment, current_page, interval.start, interval.end);
            // Generate ending points
            if (interval.end < np && this.opts.num_edge_entries > 0)
            {
                if(np-this.opts.num_edge_entries > interval.end && this.opts.ellipse_text)
                {
                    $("<span>"+this.opts.ellipse_text+"</span>").appendTo(fragment);
                }
                begin = Math.max(np-this.opts.num_edge_entries, interval.end);
                this.appendRange(fragment, current_page, begin, np, {classes:'ep'});

            }
            // Generate "Next"-Link
            currentNextPage = Math.ceil(current_page / 7) * 7;
            fragment.append(this.createLink(currentNextPage, current_page, {text:this.opts.next_text, classes:"next",rel:"next"}));

            $('a', fragment).click(eventHandler);
            return fragment;
        }
    });

    // Extend jQuery
    $.fn.pagination = function(maxentries, opts){

        opts = $.extend({
            items_per_page:7,
            num_display_entries:35,
            current_page:1,
            num_edge_entries:0,
            link_to:"#",
            prev_text:"<<",
            next_text:">>",
            ellipse_text:"...",
            prev_show_always:true,
            next_show_always:true,
            renderer:"defaultRenderer",
            show_if_single_page:true,
            load_first_page:true,
            callback:function(){return false;}
        },opts||{});

        var containers = this,
            renderer, links, current_page;

        /**
         * This is the event handling function for the pagination links. 
         * @param {int} page_id The new page number
         */
        function paginationClickHandler(evt){
            var links, 
                new_current_page = $(evt.target).data('page_id'),
                continuePropagation = selectPage(new_current_page);
            if (!continuePropagation) {
                evt.stopPropagation();
            }
            return continuePropagation;
        }

        /**
         * This is a utility function for the internal event handlers. 
         * It sets the new current page on the pagination container objects, 
         * generates a new HTMl fragment for the pagination links and calls
         * the callback function.
         */
        function selectPage(new_current_page) {
            // update the link display of a all containers
            containers.data('current_page', new_current_page);
            links = renderer.getLinks(new_current_page, paginationClickHandler);
            containers.empty();
            links.appendTo(containers);
            // call the callback and propagate the event if it does not return false
            var continuePropagation = opts.callback(new_current_page, containers);
            return continuePropagation;
        }

        // -----------------------------------
        // Initialize containers
        // -----------------------------------
        current_page = parseInt(opts.current_page, 10);
        containers.data('current_page', current_page);
        // Create a sane value for maxentries and items_per_page
        maxentries = (!maxentries || maxentries < 0)?1:maxentries;
        opts.items_per_page = (!opts.items_per_page || opts.items_per_page < 0)?1:opts.items_per_page;

        if(!$.PaginationRenderers[opts.renderer])
        {
            throw new ReferenceError("Pagination renderer '" + opts.renderer + "' was not found in jQuery.PaginationRenderers object.");
        }
        renderer = new $.PaginationRenderers[opts.renderer](maxentries, opts);

        // Attach control events to the DOM elements
        var pc = new $.PaginationCalculator(maxentries, opts);
        var np = pc.numPages();
        containers.off('setPage').on('setPage', {numPages:np}, function(evt, page_id) { 
                if(page_id >= 0 && page_id < evt.data.numPages) {
                    selectPage(page_id);
                }
        });
        containers.off('prevPage').on('prevPage', function(evt){
                var current_page = $(this).data('current_page');
                if (current_page > 0) {
                    selectPage(current_page - 1);
                }
                return false;
        });
        containers.off('nextPage').on('nextPage', {numPages:np}, function(evt){
                var current_page = $(this).data('current_page');
                if(current_page < evt.data.numPages - 1) {
                    selectPage(current_page + 1);
                }
                return false;
        });
        containers.off('currentPage').on('currentPage', function(){
                var current_page = $(this).data('current_page');
                selectPage(current_page);
                return false;
        });

        // When all initialisation is done, draw the links
        links = renderer.getLinks(current_page, paginationClickHandler);
        containers.empty();
        if(np > 1 || opts.show_if_single_page) {
            links.appendTo(containers);
        }
        // call callback function
        if(opts.load_first_page) {
            opts.callback(current_page, containers);
        }
    }; // End of $.fn.pagination block

})(jQuery);


function handlePaginationClick(new_page_index, pagination_container) {
    console.log(new_page_index);
}


$.PaginationCalculator.prototype.getInterval = function (current_page) {
    var num_display_entries = this.opts.num_display_entries;
  var start = Math.floor(current_page / num_display_entries) * num_display_entries;
  var end = Math.min(start + num_display_entries, this.numPages());

  return { start: start, end: end };
};


$("#News-Pagination").pagination(150, {
        items_per_page:7,
        num_display_entries: 7,
        callback:handlePaginationClick
});

它的作用是1-7页的组,当你点击下一页时,它会转到下一组页面(标记为1 - 7)。

除了你在该组的第一页(1)之外,一切正常。当您在第1页时,您无法单击下一步按钮。

有没有人就如何解决这个问题提出建议?

非常感谢!

1 个答案:

答案 0 :(得分:0)

将整个插件代码转储到您的问题并期望有人搜索它并尝试查找您所做的所有修改有点多。我当然不准备这样做。

但是,我想指出一些问题:

首先,您应该直接修改插件源 。在我的original answer to you中,我确保保持插件代码不变,并且显式覆盖了插件代码的<{1}}实现 。任何人拿起你的代码都是而不是知道这个插件代码已被修改,并且当行为不符合文档时会非常困惑。

其次,你应该在整个地方硬编码$.PaginationCalculator.prototype.getInterval。此插件代码旨在支持不同的配置。通过7中的硬编码,您已确保此代码将针对使用非7 num_display_entries初始化插件的任何人破解。

第三点(和第二点类似),你应该修改插件代码中的默认选项。例如,插件设计允许您在初始化时传递7prev_text的值。

虽然我不会尝试调试您的修改,但我确实看了一下原始插件源,看看是否可以满足您的新要求。我相信只需更改一行代码就可以满足您的要求。我只是更改了next_text方法中设置的默认链接文本。同样,为了保留插件源,我建议明确覆盖您要修改的方法。我已复制了该方法,并添加了关于我已更改的代码行的注释:

$.PaginationRenderers.defaultRenderer.prototype.createLink

我创建了JS Fiddle demo作为参考。