This Viewer-only form demonstrates how you can create fields that grow to display all of the text entered. Included in the sample are two fields: one standard plain text field and one configured to allow entry of rtf (rich text format) data. When a user enters text into either of these fields and then tabs out, a compute found in the field measures the height of the text and stores this result in a page global option. The field's itemlocation->height contains a compute that monitors this height and determines whether to render the field using this new height or a minimum height.
This form makes use of the viewer.measureHeight function to measure the text entered. Since the form function is part of the viewer package, it is only available when the form is rendered in the Viewer.