[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.

Public Methods

  NameDescription
AddView
Add a view to the viewable object.
(Inherited from ViewSupport.)
AttachesTo
Return null if the view will accept being attached to a particular object.
(Overrides .AttachesTo(Viewable).)
Equals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
GetEnumerator
Returns an enumerator that iterates through the collection.
(Overrides .GetEnumerator().)
GetHashCode
Serves as a hash function for a particular type. GetHashCode() is suitable for use in hashing algorithms and data structures like a hash table.
(Inherited from Object.)
GetType
Gets the Type of the current instance.
(Inherited from Object.)
GetViews
Returns all added views.
(Inherited from ViewSupport.)
static memberMakeSubViews
Instantiate subviews for the given group view and the given key value to group-by. Makes shallow copies of each child view and its subviews up to the merge point. Sets up merge data views for merging the group-by key value back in.

RemoveView
Remove a view.
(Inherited from ViewSupport.)
ToString
Returns a String that represents the current Object.
(Overrides .ToString().)
Update
Notify that data has been added or removed from the Viewable parent. The last object in the newData array of objects would be the newest object added to the parent view. The first object of the oldData array of objects would be the oldest object removed from the parent view.

If the call to update contains new (inserted) data, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted data, then the first argument will be empty and the second will be non-empty. Either the newData or oldData will be non-null. This method won't be called with both arguments being null, but either one could be null. The same is true for zero-length arrays. Either newData or oldData will be non-empty. If both are non-empty, then the update is a modification notification.

When update() is called on a view by the parent object, the data in newData will be in the collection of the parent, and its data structures will be arranged to reflect that. The data in oldData will not be in the parent's data structures, and any access to the parent will indicate that that data is no longer there.

(Overrides .Update(EventBean[](), EventBean[]()).)

Protected Methods

  NameDescription
Finalize
Allows an Object to attempt to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection.
(Inherited from Object.)
MemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)

Explicit Interface Implementations

  NameDescription
Explicit interface implemetationIEnumerable.System.Collections.IEnumerable.GetEnumerator
Returns an enumerator that iterates through a collection.
(Inherited from ViewSupport.)