is an option for cells that specifies an expression to be dynamically updated whenever the cell is visible on screen.
- CellDynamicExpression->Dynamic[expr] causes the expression to be tracked and updated in the usual way, except that expr is not displayed anywhere.
- CellDynamicExpression may not trigger dynamic updates if the cell is scrolled off screen or inside a closed cell group.
- The CellDynamicExpression dynamic is guaranteed to be resolved before any Dynamic objects that are in the cell's contents.
Introduced in 2010