ObservableGraphSourceBase
Telerik Diagramming Framework provides a list of ViewModels defined in the Telerik.Windows.Controls.Diagrams.Extensions.dll.
This article describes the ObservableGraphSourceBase<TNode, TLink> class defined in the Diagramming Extensions.
Overview
The ObservableGraphSourceBase<TNode, TLink> derives from the GraphSourceBase class and it also implements the IObservableGraphSource interface. Its main purpose is to provide an out-of-the-box ViewModel implementation that supports TwoWay binding to the RadDiagram GraphSource property.
ObservableGraphSourceBase<TNode, TLink> Inheritance Model
If you need to define a data-bound RadDiagram that has to support drag and drop of items, then you need to make sure that your custom GraphSource implementation derives from the ObservableGraphSourceBase<TNode, TLink> or from a class inheriting the ObservableGraphSourceBase<TNode, TLink> class (for instance the SerializableGraphSourceBase<TNode, TLink> class). Only then the drag/drop operations will be reflected in your ViewModels.
Inherited Properties
The ObservableGraphSourceBase<TNode, TLink> class exposes all properties it inherits from the GraphSourceBase class:
Inherited Properties
| Name | Description |
|---|---|
| InternalItems | Gets the internal ObservableCollection of business nodes. |
| InternalLinks | Gets the internal ObservableCollection of business links. |
| Items | Gets an IEnumerable collection of business nodes. |
| Links | Gets an IEnumerable collection of business links. |
Methods
The ObservableGraphSourceBase<TNode, TLink> class exposes the following virtual methods:
Virtual Methods
| Name | Description |
|---|---|
| CreateLink(object source, object target) | Creates a new ILink object associated with the specified source and target nodes. |
| CreateNode(IShape shape) | Creates a new instance of the TNode type. And as it receives an IShape object, when you override it, you can use the IShape argument to create a TNode instance associated with the specified shape. |
Inherited Virtual Methods
| Name | Description |
|---|---|
| AddNode(TNode) | Adds a specified business node to the InternalItems collection. |
| AddLink(TLink) | Adds a specified business link to the InternalLinks collection. |
| RemoveLink(TLink) | Removes a specified business link from the InternalLinks collection and returns a boolean value indicating whether the operation was successful. |
| RemoveItem(TNode) | Removes a specified business node from the InternalItems collection and returns a boolean value indicating whether the operation was successful. |
| Clear | Removes all nodes and links from the InternalItems and InternalLinks collections. |
Please note that in your solution it is best to create a custom class deriving from ObservableGraphSourceBase. Once you do so, you will be able to override all of the above virtual methods. This will allow you to describe a custom RadDiagram GraphSource class that supports TwoWay binding scenarios where any changes in the RadDiagram UI are reflected in your GraphSource implementation.