JS: jQuery plugin

JS: jQuery plugin

;(function($, document, window, undefined) {
  'use strict';

  var pluginName = 'pluginname';
  var instance = 0;

  var PluginName = function(el, options, instance) {
    this.instance = instance;
    this.options = $.extend({}, options);
    this.cache = {
      el: el
    };

    this.init();
  };

  PluginName.prototype = {
    init: function() {}
  };

  $.fn[pluginName] = function(options) {
    return this.each(function() {
      if (!$.data(this, pluginName)) {
        $.data(this, pluginName, new PluginName(this, options, instance++));
      }
    });
  };

})(jQuery, document, window);

// $(selector).pluginname();