[This topic is pre-release documentation and is subject to change in future releases. Blank topics are included as placeholders.]

The group view splits the data in a stream to multiple subviews, based on a key index. The key is one or more fields in the stream. Any view that follows the GROUP view will be executed separately on each subview, one per unique key. The view takes a single parameter which is the field name returning the key value to group. This view can, for example, be used to calculate the average price per symbol for a list of symbols. The view treats its child views and their child views as prototypes. It dynamically instantiates copies of each child view and their child views, and the child view's child views as so on. When there are no more child views or the special merge view is encountered, it ends. The view installs a special merge view unto each leaf child view that merges the value key that was grouped by back into the stream using the group-by field name.

The following tables list the members exposed by the GroupByView type.

Protected Fields

  NameDescription
parent
Parent viewable to this view - directly accessible by subclasses.
(Inherited from ViewSupport.)