Hi Paul,
Is your requirement is to have a text editor in WD application and user fills it and when click on save a dialog box should appear for confirmation? and upon confirmation, the text needs to be saved as log.
If so, you can do it as we it in abap by using standard function modules.
Create methods in assistance class and pass the text editor content to method and by using standard FMs you can create log by using the content.
Please refer the below link ( to know about function modules )
SAP ABAP: Write to SAP Application Log
To show popup confirmation in WDA
how to use confirmation popup in WDA…
Hope this helps you.
Regards,
Rama