themes/bootstrap-blog/scripts/bs_paginator.js

'use strict';

function bsPaginatorHelper(options){
  /* jshint validthis: true */
  options = options || {};

  var current = options.current || this.page.current || 0;
  var total = options.total || this.page.total || 1;
  var endSize = options.hasOwnProperty('end_size') ? +options.end_size : 1;
  var midSize = options.hasOwnProperty('mid_size') ? +options.mid_size : 2;
  var space = options.hasOwnProperty('space') ? options.space : '…';
  var base = options.base || this.page.base || this.config.root || '';
  var format = options.format || this.config.pagination_dir + '/%d/';
  var prevText = options.prev_text || 'Prev';
  var nextText = options.next_text || 'Next';
  var prevNext = options.hasOwnProperty('prev_next') ? options.prev_next : true;
  var transform = options.transform;
  var self = this;
  var result = '';
  var i;

  if (!current) return '';

  var currentPage = '<li class="active"><span class="page-number">' +
    (transform ? transform(current) : current) +
    '</span></li>';

  function link(i){
    return self.url_for(i === 1 ? base : base + format.replace('%d', i));
  }

  function pageLink(i){
    return '<li><a class="page-number" href="' + link(i) + '">' +
      (transform ? transform(i) : i) +
      '</a></li>';
  }

  // Display the link to the previous page
  if (prevNext){
    if (current > 1) {
      result += '<li><a class="page-prev" rel="prev" ' +
              'href="' + link(current - 1) + '">' + prevText + '</a></li>';
    } else {
      result += '<li class="disabled"><span class="page-prev">' + prevText + '</a></li>';
    }
  }

  if (options.show_all){
    // Display pages on the left side of the current page
    for (i = 1; i < current; i++){
      result += pageLink(i);
    }

    // Display the current page
    result += currentPage;

    // Display pages on the right side of the current page
    for (i = current + 1; i <= total; i++){
      result += pageLink(i);
    }
  } else {
    // It's too complicated. May need refactor.
    var leftEnd = current <= endSize ? current - 1 : endSize;
    var rightEnd = total - current <= endSize ? current + 1 : total - endSize + 1;
    var leftMid = current - midSize <= endSize ? current - midSize + endSize : current - midSize;
    var rightMid = current + midSize + endSize > total ? current + midSize - endSize : current + midSize;
    var spaceHtml = '<li class="disabled"><span class="page-space">' + space + '</span></li>';

    // Display pages on the left edge
    for (i = 1; i <= leftEnd; i++){
      result += pageLink(i);
    }

    // Display spaces between edges and middle pages
    if (space && current - endSize - midSize > 1){
      result += spaceHtml;
    }

    // Display left middle pages
    if (leftMid > leftEnd){
      for (i = leftMid; i < current; i++){
        result += pageLink(i);
      }
    }

    // Display the current page
    result += currentPage;

    // Display right middle pages
    if (rightMid < rightEnd){
      for (i = current + 1; i <= rightMid; i++){
        result += pageLink(i);
      }
    }

    // Display spaces between edges and middle pages
    if (space && total - endSize - midSize > current){
      result += spaceHtml;
    }

    // Dispaly pages on the right edge
    for (i = rightEnd; i <= total; i++){
      result += pageLink(i);
    }
  }

  // Display the link to the next page
  if (prevNext){
    if (current < total) {
      result += '<li><a class="page-next" rel="next" ' +
              'href="' + link(current + 1) + '">' + nextText + '</a></li>';
    } else {
      result += '<li class="disabled"><span class="page-next">' + nextText + '</a></li>';
    }
  }

  return '<nav><ul class="pagination">' + result + '</ul></nav>';
}

hexo.extend.helper.register('bs_paginator', bsPaginatorHelper);