This example shows how to set a variable using an action on a text box. That same variable is used to dynamically change the colour of the text box - feeding back that a selection has been made.
The variables once set can be used as part of expressions (including set analysis) or for determining layout - such as showing or hiding certain objects or tabs.
The QlikView was originally written as a response to the following QlikCommunity thread:
I expand on the use of Actions on buttons, text areas and gagues in my blog post on the subject: QlikView Buttons - Where, Why and How