Select the Evaluate option to allow expressions within component property values. The Evaluate option lets you compute and evaluate dynamic property settings at runtime instead of assigning static values at design time.
For some property items, the Evaluate option is by default, selected.
Use the Eval checkbox in the Properties window to enable or disable evaluation for a property. Once the Evaluate option is activated you can include JavaScript expressions in the corresponding field using square bracket notation (SBN). See “Evaluating SBN expressions”.
