(function() {
                                'use strict';
                            
                                if (CKEDITOR.plugins.get('ae_placeholder')) {
                                    return;
                                }
                            
                                /**
                                 * CKEditor plugin which allows adding a placeholder to the editor. In this case, if there
                                 * is no content to the editor, there will be hint to the user.
                                 *
                                 * @class CKEDITOR.plugins.ae_placeholder
                                 */
                            
                                /**
                                 * Specifies the placeholder class which have to be aded to editor when editor is not focuced.
                                 *
                                 * @attribute placeholderClass
                                 * @default ae_placeholder
                                 * @type String
                                 */
                            
                                CKEDITOR.plugins.add(
                                    'ae_placeholder', {
                            
                                        /**
                                         * Initialization of the plugin, part of CKEditor plugin lifecycle.
                                         * The function registers a 'blur' and 'contentDom' event listeners.
                                         *
                                         * @method init
                                         * @param {Object} editor The current editor instance
                                         */
                                        init: function(editor) {
                                            editor.on('blur', this._checkEmptyData, this);
                                            editor.on('focus', this._removePlaceholderClass, this);
                                            editor.once('contentDom', this._checkEmptyData, this);
                                        },
                            
                                        /**
                                         * Removes any data from the content and adds a class,
                                         * specified by the "placeholderClass" config attribute.
                                         *
                                         * @protected
                                         * @method _checkEmptyData
                                         * @param {CKEDITOR.dom.event} editor event, fired from CKEditor
                                         */
                                        _checkEmptyData: function(event) {
                                            var editor = event.editor;
                            
                                            var editorNode = new CKEDITOR.dom.element(editor.element.$);
                            
                                            if (editor.getData() === '') {
                            
                                                editorNode.addClass(editor.config.placeholderClass);
                                            }
                                        },
                            
                                        /**
                                         * Remove placeholder class when input is focused
                                         *
                                         * @protected
                                         * @method _removePlaceholderClass
                                         + @param {CKEDITOR.dom.event} editor event, fired from CKEditor
                                         */
                                        _removePlaceholderClass: function(event) {
                                            var editor = event.editor;
                            
                                            var editorNode = new CKEDITOR.dom.element(editor.element.$);
                            
                                            editorNode.removeClass(editor.config.placeholderClass);
                                        }
                                    }
                                );
                            }());