One possible solution. 1. Use UniSyntaxEditEx instead of UniSyntaxEdit. 2. UniSyntaxEditEx.ClientEvents.UniEvents -> function afterCreate(sender) { sender.insertTextAtCursor = function(str) { var editor = this.codeEditor; var selection = editor.getSelection(); if (selection.length > 0) { editor.replaceSelection(str); } else { var doc = editor.getDoc(); var cursor = doc.getCursor(); va