jquery.pager.js

/**
 * jQuery Pager plugin
 * Licensed under the MIT license
 * This plugin is refer to how to write "jQuery ScrollSpy Plugin".
 */
 (function(factory) {
     'use strict';
     if (typeof define === 'function' && define.amd) {
         define(['jquery'], factory);
     } else if (typeof exports !== 'undefined') {
         module.exports = factory(require('jquery'));
     } else {
         factory(jQuery);
     }

 }(function($) {

   $.fn.extend({
     pager: function pager(options, action) {
       // If the options parameter is a string, then assume it's an 'action', therefore swap the parameters around
       if (_isString(options)) {
           var tempOptions = action;

           // Set the action as the option parameter
           action = options;

           // Set to be the reference action pointed to
           options = tempOptions;
       }

       // override the default options with those passed to the plugin
       options = $.extend(true, {}, _defaults, options);

       // sanitize the following option with the default value if the predicate fails
       _sanitizeOption(options, _defaults, 'namespace', _isString);
       _sanitizeOption(options, _defaults, 'elements', _isObject);
       _sanitizeOption(options, _defaults, 'step', _isNumeric);
       _sanitizeOption(options, _defaults, 'current', _isNumeric);
       _sanitizeOption(options, _defaults, 'total', _isNumeric);
       _sanitizeOption(options, _defaults, 'onPageing', $.isFunction);

       var _current = options.current, //現在のページ
           _total = options.total; //総ページ数

       if(_isString(action)) {
         switch(action) {
           case 'set':
             if(options.current) {
               _current = options.current;
             }
             if(options.total) {
               _current = options.total;
             }
             _setElements($(this), options, _current, _total);
           break;
           default:
         }
       }

       return this.each(function each() {
           var _this = this;
           var $element = $(_this);

           var $prev = $element.find(options.elements.prev),
               $next = $element.find(options.elements.next),
               $current = $element.find(options.elements.current),
               $total = $element.find(options.elements.total);

           if($prev && $prev.length) {
             $prev.toggle(_current > 1);
           }

           if($next && $next.length) {
             $next.toggle(_current < _total);
           }

           $element.on('click' + options.namespace, options.elements.prev + ',' + options.elements.next, function (e) {
             e.preventDefault();

             if($(this).hasClass(options.elements.next.replace('.', ''))) {
               _current = Math.min(_current + 1, _total);
             } else {
               _current = Math.max(_current - 1, 1);
             }

             $current.text(_current);

             if($prev && $prev.length) {
               $prev.toggle(_current > 1);
             }

             if($next && $next.length) {
               $next.toggle(_current < _total);
             }

             if (options.onPaging !== null) {
               options.onPaging(e, options, _current, _total);
             }
           });

       });
     }
   });

   function _setElements($element, options, current, total) {
     var $prev = $element.find(options.elements.prev),
         $next = $element.find(options.elements.next),
         $current = $element.find(options.elements.current),
         $total = $element.find(options.elements.total);

       if($prev && $prev.length) {
         $prev.toggle(current > 1);
       }

       if($next && $next.length) {
         $next.toggle(current < total);
       }
       $current.text(current);
       $total.text(total);
   }

   // default options
   var _defaults = {
     namespace: '.c-pager',
     step: 10,
     current: 1, //現在のページ
     total: 1, //総ページ数
     elements: {
       prev: '.c-pager__prev',
       next: '.c-pager__next',
       current: '.c-pager__current',
       total: '.c-pager__total'
     },
     onPaging: null
   };

   // Methods (Private)
   function _isObject(value) {
     return $.type(value) === 'object';
   }
   function _isNumeric(value) {
     return $.type(value) === 'number';
   }

   function _isString(value) {
     return $.type(value) === 'string' && $.trim(value).length > 0;
   }

   function _sanitizeOption(options, defaults, property, predicate) {
     if (!predicate(options[property])) {
         options[property] = defaults[property];
     }
   }
 }));