Choice Object

Represents a unit of information available for sharing between objects.

Syntax

Choice

Remarks

A Choice object has a set of fixed properties and can also have a set of DTC-specific properties. You can implement DTC-specific properties by specifying name-value pairs in a Tags collection associated with the Choice object. The fixed properties have well-defined semantics such as name and type properties. By specifying a Tags collection to the Choice object, you can provide name-value pairs specific to your DTC.

For example, a choice that identifies a fruit type, might have tags such as CostPerPound, DeliveryTime, or color.

A Choice object has two basic parts:

• A fixed schema that is a set of properties with well-defined semantics such as its text, description, and type.
  
  
• A variable schema made up of developer-defined name-value pairs associated with the Choice.

DTCs share information with each other by creating, publishing, filtering, and subscribing to Choice objects. A Choice object can contain arbitrary information, but is always managed as an atomic unit.

DTC objects can process Choice objects in the following ways:

• Publishing Choice objects by broadcasting the Choice to other DTC objects that are within the same scope.
  
  
• Subscribing to Choice objects by looking for and interpreting Choice objects that are published by other DTC objects. Multiple DTC objects can subscribe to a single choice.
  
  
• Filtering Choice objects by allowing objects to control the visibility of choices published by other objects. For example, the Choice objects published by one DTC object may be invalidated by another DTC object and should not be visible.

See also   Defining a Choice