Limiting data using a property expression
In this example, a property expression is used to pick out details for a certain category from a bar chart that is otherwise quite packed with information. The stacked bars show the amounts of protein, carbohydrates, and fat in different items of food.
Before you begin
About this task
Assume you want to look closer at one item at a time, and you want to
specify which item to look at from a text area, as shown below.
Procedure
-
In a text area,
add the property control, in this case, a
drop-down list.
-
In the
Property Control dialog, create the property via
New. Give it a name, specify its data type and
a start value. In this example, we call the property 'FoodItem'.
-
When the property exists and has been selected, define which
values the property should be able to have. In this example, the unique values
in the 'Food' column should be available for selection in the drop-down list.
-
Finally, connect the property to the Limit data using
expression setting on the
Data page of the
Properties dialog (via
Edit). The expression excludes all other food
types except the value of the property as currently selected in the drop-down
list.
