You can add filters, calculated values, Spotfire property controls etc in a Text Area. These controls should be considered as Spotfire objects which are translated into HTML when they are rendered. It is not recommended to rely on the rendered HTML for these controls as it may change in future versions of TIBCO Spotfire.
How to signal when the text area is ready to be rendered to PDF or image
If your script contains asynchronous calls, you need to use the SF.setBusy() API to make sure the text area will render nicely when exported to PDF or image.
the export browser will not render a pdf/image until the script executes: