I was thinking about creating a very simple app with a rectangle where the user can insert a text (precisely a number). In this case the code makes a simple mathematical operation and shows on the screen the result. My main trouble here is being to find a way to make the phone keyboard pop up when clicking on the text-box, so that the user can write his number. Thank you in advance for your help, I hope I’ve been clear!
Are you looking for this - https://docs.coronalabs.com/api/library/native/setKeyboardFocus.html ?
Thank you! My only doubt was this: can I detect the submitted text and make it a local?
Yes, sure you can. You might want to look into native text field examples.