Paginator

example_paginator.js

/**
 * Simple example use of Paginator and jQuery
 * @requires jQuery
 * @requires Paginator.js
 */

var pager = new Paginator();

pager.setCurrent(5);
pager.setLast(23);

var list = $("<ul class='pagelist'/>");

var addPage = function(i, val){ $("<li><a href='foo/"+val+"' />"+val+"</a></li>").appendTo(list) });

$.each(pager.getHead(), addPage);
list.append("<li>...</li>");
$.each(pager.getBody(), addPage);
list.append("<li>...</li>");
$.each(pager.getTail(), addPage);

list.appendTo("body");

paginator.coffee

###*
 * @fileOverview Script for generating Flickr style pagination. 
 * @author Jo-Herman Haugholt <jo-herman.haugholt@sectoralarm.com>
 ###

###*
 * @class Pagination object. Instances of this class can return the head, body and tail subsets of pages.
 ###
class Paginator
    ###* 
     * @public
     * @property {number} first The first page
     * @default 1 
     ###
    "first": null
    
    ###* 
     * @public
     * @property {number} last The last page. Required.
     ###
    "last": null
    
    ###* 
     * @private
     * @property {number} next The next page.
     ###
    "next": undefined
    
    ###* 
     * @private
     * @property {number} prev The previous page
     ###
    "prev": undefined

    ###*
     * @private
     * @property {number} current The current page
     ###
    "current": undefined

    ###* 
     * @public
     * @property {number} peek How many pages to "peek" before and after the 
     *                         previous and next page respectivly.
     * @default 2 
     ###
    "peek": 2

    ###* @constructor ###
    constructor: (@first=1, @last, @next, @prev, @current)->

    ###* 
     * @public
     * @function 
     * @returns {number} The current page. If <code>undefined</code>, it is extrapolated from
     *                   {@link next} and/or {@link prev}. If it can't be extrapolated, it
     *                   returns <code>undefined</code>.
     ###
    "getCurrent": ->
        return @current if @current?
        return (@next+@prev)/2 if @next? and @prev?
        return @next-1 if @next?
        return @prev+1 if @prev?
        return undefined

    "setCurrent": (@current) ->

    ###*
    * @public
    * @function
    * @returns {number} The next page. If <code>undefined</code>, and {@link current} is defined
    *                   it will try to extrapolate the next page. Otherwise it returns
    *                   <code>undefined</code>.
    ###
    "getNext": ->
        return @next                         if @next?
        return undefined                     if not @current?
        return @current - (@prev - @current) if @prev?
        return @current+1

    "setNext": (@next) ->

    ###*
    * @public
    * @function
    * @returns {number} The previous page. If <code>undefined</code>, and {@link current} is
    *                   defined it will try to extrapolate the previous page. Otherwise it
    *                   returns <code>undefined</code>.
    ###
    "getPrev": ->
        return @prev                         if @prev?
        return undefined                     if not @current?
        return @current - (@next - @current) if @next?
        return @current-1

    "setPrev": (@prev) ->

    "getLast": -> @last
    "setLast": (@last) ->

    ###* 
     * @public
     * @function 
     * @returns {Array.<number>} An array containing the "head" pages. If 
     *                           {@link first} would be included in the "body" 
     *                           pages, this function will return an empty array.
     ###
    "getHead": ->
        current = @getCurrent()
        i = @peek+1
        j = 2*i
        k = 3*i-1
        if not current? or current < @first+k then return []
        else
            end = @first+@peek-1
            end = @last if end > @last
            [@first..end]

    ###* 
     * @public
     * @function 
     * @returns {Array.<number>} An array containing the "body" of pages. 
     ###
    "getBody": ->
         current = @getCurrent()
         if not current? then return [@first..@last]
         
         i = @peek+1
         j = 2*i
         k = 3*i-1

         prev = @getPrev()

         start = if prev? then prev-@peek else @first
         start = @first if start < @first
         start = @last - j if current >= @last-i
         start = @first if current < @first+k

         next = @getNext()

         end   = if next? then next+@peek else @last
         end   = @last if end > @last
         end   = @first + j if current <= @first+i
         end   = @last if current > @last-k

         [start..end]

    ###* 
     * @public
     * @function 
     * @returns {Array.<number>} An array containing the "tail" pages. If 
     *                           {@link last} would be included in the "body" 
     *                           pages, this function will return an empty array.
     ###
    "getTail": ->
        current = @getCurrent()
        i = @peek+1
        j = 2*i
        k = 3*i-1
        if not current? or current > @last-k then return []
        else 
            start = @last-@peek+1
            start = @first if start < @first
            return [start..@last]
        

window["Paginator"] = Paginator

paginator.js

(function() {
  /**
   * @fileOverview Script for generating Flickr style pagination. 
   * @author Jo-Herman Haugholt <jo-herman.haugholt@sectoralarm.com>
   */
  /**
   * @class Pagination object. Instances of this class can return the head, body and tail subsets of pages.
   */  var Paginator;
  Paginator = (function() {
    /** 
     * @public
     * @property {number} first The first page
     * @default 1 
     */    Paginator.prototype["first"] = null;
    /** 
     * @public
     * @property {number} last The last page. Required.
     */
    Paginator.prototype["last"] = null;
    /** 
     * @private
     * @property {number} next The next page.
     */
    Paginator.prototype["next"] = void 0;
    /** 
     * @private
     * @property {number} prev The previous page
     */
    Paginator.prototype["prev"] = void 0;
    /**
     * @private
     * @property {number} current The current page
     */
    Paginator.prototype["current"] = void 0;
    /** 
     * @public
     * @property {number} peek How many pages to "peek" before and after the 
     *                         previous and next page respectivly.
     * @default 2 
     */
    Paginator.prototype["peek"] = 2;
    /** @constructor */
    function Paginator(first, last, next, prev, current) {
      this.first = first != null ? first : 1;
      this.last = last;
      this.next = next;
      this.prev = prev;
      this.current = current;
    }
    /** 
     * @public
     * @function 
     * @returns {number} The current page. If <code>undefined</code>, it is extrapolated from
     *                   {@link next} and/or {@link prev}. If it can't be extrapolated, it
     *                   returns <code>undefined</code>.
     */
    Paginator.prototype["getCurrent"] = function() {
      if (this.current != null) {
        return this.current;
      }
      if ((this.next != null) && (this.prev != null)) {
        return (this.next + this.prev) / 2;
      }
      if (this.next != null) {
        return this.next - 1;
      }
      if (this.prev != null) {
        return this.prev + 1;
      }
    };
    Paginator.prototype["setCurrent"] = function(current) {
      this.current = current;
    };
    /**
    * @public
    * @function
    * @returns {number} The next page. If <code>undefined</code>, and {@link current} is defined
    *                   it will try to extrapolate the next page. Otherwise it returns
    *                   <code>undefined</code>.
    */
    Paginator.prototype["getNext"] = function() {
      if (this.next != null) {
        return this.next;
      }
      if (!(this.current != null)) {
        return;
      }
      if (this.prev != null) {
        return this.current - (this.prev - this.current);
      }
      return this.current + 1;
    };
    Paginator.prototype["setNext"] = function(next) {
      this.next = next;
    };
    /**
    * @public
    * @function
    * @returns {number} The previous page. If <code>undefined</code>, and {@link current} is
    *                   defined it will try to extrapolate the previous page. Otherwise it
    *                   returns <code>undefined</code>.
    */
    Paginator.prototype["getPrev"] = function() {
      if (this.prev != null) {
        return this.prev;
      }
      if (!(this.current != null)) {
        return;
      }
      if (this.next != null) {
        return this.current - (this.next - this.current);
      }
      return this.current - 1;
    };
    Paginator.prototype["setPrev"] = function(prev) {
      this.prev = prev;
    };
    Paginator.prototype["getLast"] = function() {
      return this.last;
    };
    Paginator.prototype["setLast"] = function(last) {
      this.last = last;
    };
    /** 
     * @public
     * @function 
     * @returns {Array.<number>} An array containing the "head" pages. If 
     *                           {@link first} would be included in the "body" 
     *                           pages, this function will return an empty array.
     */
    Paginator.prototype["getHead"] = function() {
      var current, end, i, j, k, _i, _ref, _results;
      current = this.getCurrent();
      i = this.peek + 1;
      j = 2 * i;
      k = 3 * i - 1;
      if (!(current != null) || current < this.first + k) {
        return [];
      } else {
        end = this.first + this.peek - 1;
        if (end > this.last) {
          end = this.last;
        }
        return (function() {
          _results = [];
          for (var _i = _ref = this.first; _ref <= end ? _i <= end : _i >= end; _ref <= end ? _i++ : _i--){ _results.push(_i); }
          return _results;
        }).apply(this, arguments);
      }
    };
    /** 
     * @public
     * @function 
     * @returns {Array.<number>} An array containing the "body" of pages. 
     */
    Paginator.prototype["getBody"] = function() {
      var current, end, i, j, k, next, prev, start, _i, _j, _ref, _ref2, _results, _results2;
      current = this.getCurrent();
      if (!(current != null)) {
        return (function() {
          _results = [];
          for (var _i = _ref = this.first, _ref2 = this.last; _ref <= _ref2 ? _i <= _ref2 : _i >= _ref2; _ref <= _ref2 ? _i++ : _i--){ _results.push(_i); }
          return _results;
        }).apply(this, arguments);
      }
      i = this.peek + 1;
      j = 2 * i;
      k = 3 * i - 1;
      prev = this.getPrev();
      start = prev != null ? prev - this.peek : this.first;
      if (start < this.first) {
        start = this.first;
      }
      if (current >= this.last - i) {
        start = this.last - j;
      }
      if (current < this.first + k) {
        start = this.first;
      }
      next = this.getNext();
      end = next != null ? next + this.peek : this.last;
      if (end > this.last) {
        end = this.last;
      }
      if (current <= this.first + i) {
        end = this.first + j;
      }
      if (current > this.last - k) {
        end = this.last;
      }
      return (function() {
        _results2 = [];
        for (var _j = start; start <= end ? _j <= end : _j >= end; start <= end ? _j++ : _j--){ _results2.push(_j); }
        return _results2;
      }).apply(this, arguments);
    };
    /** 
     * @public
     * @function 
     * @returns {Array.<number>} An array containing the "tail" pages. If 
     *                           {@link last} would be included in the "body" 
     *                           pages, this function will return an empty array.
     */
    Paginator.prototype["getTail"] = function() {
      var current, i, j, k, start, _i, _ref, _results;
      current = this.getCurrent();
      i = this.peek + 1;
      j = 2 * i;
      k = 3 * i - 1;
      if (!(current != null) || current > this.last - k) {
        return [];
      } else {
        start = this.last - this.peek + 1;
        if (start < this.first) {
          start = this.first;
        }
        return (function() {
          _results = [];
          for (var _i = start, _ref = this.last; start <= _ref ? _i <= _ref : _i >= _ref; start <= _ref ? _i++ : _i--){ _results.push(_i); }
          return _results;
        }).apply(this, arguments);
      }
    };
    return Paginator;
  })();
  window["Paginator"] = Paginator;
}).call(this);