A simple modal constructor with Private and Public methods

Modal.js

/*
 * How to use:
 * var modal = new Modal({
 *   modalBackground: $('#manual-mode-modal'),
 *   modalDialog: $('#manual-mode-modal-wrapper')
 * });
 *
 * modal.openModal();
 * modal.closeModal();
*/

define(function(require){
  
  'use strict';

  var $ = require('jquery');
  var _ = require('lodash');

  ////////////////////////////////////////////////////////////////////////
  // Private API
  ////////////////////////////////////////////////////////////////////////

  var _Private = function(){
    'use strict';
  };

  _Private.prototype = Object.create(Object.prototype);
  _Private.prototype.constructor = _Private;

  _Private.prototype.openModalBackground = function(instance){
    'use strict';
    instance.modalBackground.removeClass('hide');
  };

  _Private.prototype.closeModalBackground = function(instance){
    'use strict';
    instance.modalBackground.addClass('hide');
  };

  _Private.prototype.displayModalDialog = function(instance){
    'use strict';
    if ( instance.modalDialog === null || instance.modalDialog === undefined ) {
      return;
    }
    instance.modalDialog.removeClass('hide');
  };

  _Private.prototype.hideModalDialog = function(instance){
    'use strict';
    if ( instance.modalDialog === null || instance.modalDialog === undefined ) {
      return;
    }
    instance.modalDialog.addClass('hide');
  };

  _Private.prototype.verticallyCenterModal = function(instance){
    'use strict';
    if ( instance.modalDialog === null || instance.modalDialog === undefined ) {
      return;
    }
    var bg_height = instance.modalBackground.outerHeight();
    var modal_height = instance.modalDialog.outerHeight();
    var modalTopOffset = _.round( (bg_height / 2) - (modal_height / 2) );
    instance.modalDialog.css('top', modalTopOffset + 'px');
  };

  _Private.prototype.runBeforeOpenModal = function(instance){
    'use strict';
    if ( instance.runBeforeOpenModal === null || instance.runBeforeOpenModal === undefined ) {
      return;
    }
    instance.runBeforeOpenModal( instance );
  };

  _Private.prototype.runAfterCloseModal = function(instance){
    'use strict';
    if ( instance.runAfterCloseModal === null || instance.runAfterCloseModal === undefined ) {
      return;
    }
    instance.runAfterCloseModal( instance );
  };

  var _private = new _Private();

  ////////////////////////////////////////////////////////////////////////
  // Public API
  ////////////////////////////////////////////////////////////////////////

  var Fn = function(options){
    'use strict';
    this.modalBackground = options.modalBackground || null;
    this.modalDialog = options.modalDialog || null;
    this.runBeforeOpenModal =  options.runBeforeOpenModal || null;
    this.runAfterCloseModal =  options.runAfterCloseModal || null;
    this.data =  options.data || null;
    return this;
  };

  Fn.prototype = Object.create(Object.prototype);
  Fn.prototype.constructor = Fn;

  Fn.prototype.openModal = function(){
    'use strict';
    _private.runBeforeOpenModal( this );
    _private.openModalBackground( this );
    _private.verticallyCenterModal( this );
    _private.displayModalDialog( this );
  };

  Fn.prototype.closeModal = function(){
    'use strict';
    _private.closeModalBackground( this );
    _private.hideModalDialog( this );
    _private.runAfterCloseModal( this );
  };

  return Fn;

});