fx:False markup extension

The fx:False markup extension specifies the boolean false value.

In many cases, using the fx:False markup extension is not necessary. In a boolean assignment context, the text "false" is automatically converted to a boolean value.

Text assignment is target-typed, so the text "false" has no intrinsic boolean type. In particular, assigning value="false" to an Object property produces the string "false". Use {fx:False} when the value must be Boolean regardless of the assignment target.

As a method argument, the unquoted keyword false is a boolean literal. Quote it as 'false' to pass a string, or qualify it as a path such as :element.false to refer to a property named false.

Usage

<!-- Using the fx:False markup extension -->
<Button visible="{fx:False}"/>

<!-- Using type coercion -->
<Button visible="false"/>

<!-- The Object-valued property receives Boolean.FALSE, not the string "false" -->
<Button userData="{fx:False}"/>

<!-- Boolean and string literals as method arguments -->
<Button text="$String.format('%s / %s', false, 'false')"/>