(propertyName?: string, defaultValue?: any): Binding

Returns a new binding, which can be used as a component preset (see Component.with) to update components dynamically with the value of an observed property on the bound parent component, such as the AppActivity for a view, the Application for an activity, or the ViewComponent for nested views.

The bound property name is specified using the first argument. Nested properties are allowed (e.g., but only the first property will be observed.

If a nested property does not exist, but a get method does (e.g. ManagedMap.get()), then this method is called with the property name as its only argument, and the resulting value used as the bound value.

The property name may be appended with a | (pipe) character and a filter name: see Binding.addFilter for available filters. Multiple filters may be chained together if their names are separated with more pipe characters.

For convenience, !property is automatically rewritten as property|! to negate property values, and !!property to convert any value to a boolean value.

A default value may also be specified. This value is used when the bound value itself is undefined.

See Also

bindf, Binding.addFilter (includes a list of available filters)