Here is the solution for those who want to use autoExpand property in a multiline textbox, included in a hidden element.

(for  example you use a switch button, and when the user activates the switch, you show a textbox where the user can add commentaries.)

the issue is : you can’t use autoExpand property directly : smart-multiline-text-box cannot calculate the height of the textbox as the height of a hidden element is 0.

The result is that when the textbox appears, you can’t clic in it.

This CodePen reproduces the issue :

https://codepen.io/mogador/pen/OJveMBm

Now the Solution :

crate a dynamic object with the div tag, and set the property autoExpand to true AFTER showing the parent element.

https://codepen.io/mogador/pen/mdxZvRm

fabriceb