Designers are represented by instances of the NDesigner class. There is a designer associated with each NNode Schema. If not explicitly specified, by default an instance of the NDesigner class is created to serve as node designer.

Designers provide information about the editors that need to be created for certain schema members, the editors that need to be created when the node is the root edited node, or is edited as part of other nodes hierarchy etc. The relation between the designer and the node editors is discussed in the Designers and Editors topic.

Designers also define node members (properties and container children) categorization. This allows the user to see related members grouped together in their respective categories (e.g. - General, Appearance, Behavior are common categories used to group node members).  The Member Categories topic discusses this in details.

Designers also provide a set of actions that are commonly performed with the node instance, as discussed by the Commands and Verbs topic.

The rest of this topic focuses on how to assign a custom designer to a node schema.

public class MyNode : NNode
{
    public MyNode() { }
    static MyNode()
    {
        MyNodeSchema = NSchema.Create(typeof(MyNode), NNode.NNodeSchema);
        // set designer type for MyNode
        MyNodeSchema.SetMetaUnit(new NDesignerMetaUnit(typeof(MyNodeDesigner)));
    }
    public static readonly NSchema MyNodeSchema;
    public class MyNodeDesigner : NDesigner
    {
        public MyNodeDesigner()
        {
            // TODO: Init designer here
        }
    }
}

// get the designer for nodes of type MyNode
NDesigner myNodeDesigner = NDesigner.GetDesigner(MyNode.MyNodeSchema);