jQuery plugin that provides auto-extension (currently `width` is only supported) to elements

jquery.autoAdjust.js

/**
 * ex)
 * <input type="text" class="jq-auto-adjust" data-base-width="60" data-base-window-width="1280">
 * $('.jq-auto-adjust').autoAdjust();
 */
(function($) {
    'use strict';

    var methods = {
        init: function(options) {
            var settings = $.extend({
                baseWidth: 'current', // number(px) or 'current'
                baseWindowWidth: 'current', // number(px) or 'current'
            }, options);

            return this.each(function() {
                var $this = $(this);
                var autoAdjust = new AutoAdjust($this, mergeOptions($this, settings));
                autoAdjust.observe();
                $this.data('plugin_auto_adjust', autoAdjust);
            });
        },

        off: function() {
            return this.each(function() {
                var autoAdjust = $(this).data('plugin_auto_adjust');
                autoAdjust.stopObserving();
            });
        },
    };

    var mergeOptions = function($el, settings) {
        return $.extend({}, settings, $el.data());
    };

    $.fn.autoAdjust = function(method) {
        if (methods[method]) {
            return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
        } else if (typeof method === 'object' || !method) {
            return methods.init.apply(this, arguments);
        } else {
            $.error('Method ' +  method + ' does not exist on jQuery.autoAdjust');
        }
    };

    
    var AutoAdjust = (function() {

        var NAMESPACE = '.auto_adjust';

        var AutoAdjust = function($el, settings) {
            this.$el = $el;
            this.$window = $(window);

            this.baseWidth = settings.baseWidth === 'current' ? this.$el.width() : settings.baseWidth;
            this.baseWindowWidth = settings.baseWindowWidth === 'current' ? this.$window.width() : settings.baseWindowWidth;
        };

        $.extend(AutoAdjust.prototype, {

            observe: function() {
                this.$window.on('resize' + NAMESPACE, this._bind('onResize'));
                this.adjust();
            },

            stopObserving: function() {
                this.$window.off(NAMESPACE);
            },

            onResize: function(e) {
                this.adjust();
            },

            adjust: function() {
                var diff = this.$window.width() - this.baseWindowWidth;
                var width = this.baseWidth + diff;
                if (width < 1) width = 1;
                this.$el.width(width);
            },

            _bind: function(funcName) {
                var that = this;
                return function() { that[funcName].apply(that, arguments) };
            },
        });

        return AutoAdjust;
    })();
})(jQuery);