server/web/paginate-helper.js

   1 'use strict';
   2
   3 function requiredBlock(context, page, pageCount, fn) {
   4   if (page > 1 || pageCount > 1) {
   5     return fn(context);
   6   } else {
   7     return '';
   8   }
   9 }
  10
  11 function middleBlock(page, pageCount, limit, fn) {
  12   function contextForItem(pageNumber) {
  13     return {
  14       n: pageNumber,
  15       active: pageNumber === page
  16     };
  17   }
  18
  19   var i;
  20   var ret = '';
  21   if (typeof limit === 'number') {
  22     i = 0;
  23     var leftCount = Math.ceil(limit / 2) - 1;
  24     var rightCount = limit - leftCount - 1;
  25     if (page + rightCount > pageCount) leftCount = limit - (pageCount - page) - 1;
  26     if (page - leftCount < 1) leftCount = page - 1;
  27     var start = page - leftCount;
  28
  29     while (i < limit && i < pageCount) {
  30       ret = ret + fn(contextForItem(start));
  31       start++;
  32       i++;
  33     }
  34   } else {
  35     for (i = 1; i <= pageCount; i++) {
  36       ret = ret + fn(contextForItem(i));
  37     }
  38   }
  39
  40   return ret;
  41 }
  42
  43 function previousBlock(page, pageCount, fn) {
  44   if (page === 1) {
  45     return fn({ disabled: true, n: 1 });
  46   } else {
  47     return fn({ n: page - 1 });
  48   }
  49 }
  50
  51 function nextBlock(page, pageCount, fn) {
  52   if (page === pageCount) {
  53     return fn({ disabled: true, n: pageCount });
  54   } else {
  55     return fn({ n: page + 1 });
  56   }
  57 }
  58
  59 function firstBlock(page, pageCount, fn) {
  60   if (page === 1) {
  61     return fn({ disabled: true, n: 1 });
  62   } else {
  63     return fn({ n: 1 });
  64   }
  65 }
  66
  67 function lastBlock(page, pageCount, fn) {
  68   if (page === pageCount) {
  69     return fn({ disabled: true, n: pageCount });
  70   } else {
  71     return fn({ n: pageCount });
  72   }
  73 }
  74
  75 module.exports = function(pagination, options) {
  76   var type = options.hash.type || 'middle';
  77
  78   var pageCount = Number(pagination.pageCount);
  79   var page = Number(pagination.page);
  80   var limit;
  81   if (options.hash.limit) limit = +options.hash.limit;
  82   var fn = options.fn;
  83
  84   switch (type) {
  85     case 'required':
  86       return requiredBlock(this, page, pageCount, fn);
  87
  88     case 'middle':
  89       return middleBlock(page, pageCount, limit, fn);
  90
  91     case 'previous':
  92       return previousBlock(page, pageCount, fn);
  93
  94     case 'next':
  95       return nextBlock(page, pageCount, fn);
  96
  97     case 'first':
  98       return firstBlock(page, pageCount, fn);
  99
 100     case 'last':
 101       return lastBlock(page, pageCount, fn);
 102   }
 103
 104   return '';
 105 };