GraphChanges

Description

The set of changes to a graph reported to Graph.OnGraphChanged in a single change event.

Access this through GraphLogger.GraphChanges inside Graph.OnGraphChanged. Inspect GraphChanges.ChangedNodes, GraphChanges.ChangedVariables, GraphChanges.ChangedConstantNodes, and GraphChanges.ChangedSubgraphNodes to react to what was added or modified. Each entry's ChangeKinds property is a set of ChangeKind bit-flags describing the categories of change that apply. Removed elements are not reported, except for removed ports, which appear in ChangedNode.ChangedPorts on their owning node.

 public override void OnGraphChanged(GraphLogger graphLogger)
 {
     GraphChanges changes = graphLogger.GraphChanges;

     foreach (ChangedNode changedNode in changes.ChangedNodes)
     {
         if ((changedNode.ChangeKinds & ChangeKind.Added) != 0)
             Debug.Log($"Node added: {changedNode.Node}");

         if ((changedNode.ChangeKinds & ChangeKind.Data) != 0)
             Debug.Log($"Node data changed: {changedNode.Node}");

         if ((changedNode.ChangeKinds & ChangeKind.Layout) != 0)
             Debug.Log($"Node moved or resized: {changedNode.Node}");

         // Node is either a user-defined Node subclass or an IVariableNode.
         switch (changedNode.Node)
         {
             case IVariableNode variableNode: /* variable reference */ break;
             case Node userNode:              /* user-defined node */  break;
         }

         // When ChangeKind.PortChanged is set, inspect ChangedPorts for details.
         foreach (ChangedPort changedPort in changedNode.ChangedPorts)
         {
             if ((changedPort.ChangeKinds & ChangeKind.Removed) != 0)
                 Debug.Log($"  Port removed: {changedPort.ID}");
             else
                 Debug.Log($"  Port changed: {changedPort.Port?.Name} ({changedPort.ChangeKinds})");
         }
     }

     foreach (ChangedVariable changedVariable in changes.ChangedVariables)
         Debug.Log($"Variable changed: {changedVariable.Variable.Name} ({changedVariable.ChangeKinds})");

     foreach (ChangedConstantNode changedConstant in changes.ChangedConstantNodes)
         Debug.Log($"Constant node changed: {changedConstant.ConstantNode} ({changedConstant.ChangeKinds})");

     foreach (ChangedSubgraphNode changedSubgraph in changes.ChangedSubgraphNodes)
         Debug.Log($"Subgraph node changed: {changedSubgraph.SubgraphNode} ({changedSubgraph.ChangeKinds})");
 }

Properties