Index: lams_central/web/includes/javascript/ckconfig_custom.js
===================================================================
diff -u -rebf117035c692f7069000d6b7bace23cfc94619a -r394f403c289f0fd7808c228840bead5c4e7d5d32
--- lams_central/web/includes/javascript/ckconfig_custom.js	(.../ckconfig_custom.js)	(revision ebf117035c692f7069000d6b7bace23cfc94619a)
+++ lams_central/web/includes/javascript/ckconfig_custom.js	(.../ckconfig_custom.js)	(revision 394f403c289f0fd7808c228840bead5c4e7d5d32)
@@ -131,7 +131,7 @@
 CKEDITOR.config.format_tags	= 'div;h1;h2;h3;h4;h5;h6;pre;address;p' ;
 CKEDITOR.config.enterMode = 'div';
 CKEDITOR.plugins.addExternal('wikilink', CKEDITOR.basePath + '../tool/lawiki10/wikilink/', 'plugin.js');
-CKEDITOR.config.extraPlugins = 'wikilink,jlatexmath,image2,html5audio,bootstrapTabs,bootpanel,bootsnippets';
+CKEDITOR.config.extraPlugins = 'wikilink,jlatexmath,image2,html5audio,confighelper,bootstrapTabs,bootpanel,bootsnippets';
 CKEDITOR.config.enterMode = CKEDITOR.ENTER_DIV; 
 CKEDITOR.config.removePlugins = 'elementspath,about,specialchar';
 CKEDITOR.config.allowedContent = true;
@@ -145,6 +145,16 @@
 // ---- Additional scripts -----
 
 CKEDITOR.on('instanceReady', function(e){
+	//add custom classes
+	var classes = e.editor.config.classes;
+	if (classes) {
+		for (classIter of classes.split(' ')) {
+			if (classIter) {
+				e.editor._.editable.$.classList.add(classIter);
+			}
+	    }
+	}
+	
 	//set min-height CSS property
 	var height = e.editor.config.height;
 	if ( ! height ) {
@@ -169,4 +179,22 @@
 		
 		f.data.dataValue = tempDiv.innerHTML;
 	});
+	
+	//function adds "cke_filled" class to CKEditor, if it's not empty. And removes it otherwise.
+	var placeholderLessenHandler = function(editor) {
+		var ckeditorData = editor.getData();
+		
+		var isEmpty = (ckeditorData == null) || (ckeditorData.replace(/&nbsp;| |<br \/>|\s|<p>|<\/p>|\xa0/g, "").length == 0);
+		if (isEmpty) {
+			editor._.editable.$.classList.remove("cke_filled");
+		} else {
+			editor._.editable.$.classList.add("cke_filled");
+		}
+	}
+	//add cke_filled class on editor's instanceReady
+	placeholderLessenHandler(e.editor);
+	//add cke_filled class on editor gets changed
+	e.editor.on('change', function(event) {
+		placeholderLessenHandler(event.editor);
+	});
 });