Loading project from XML issue

[LaurentiuVasile]

Hello Michael,

Lawrence here... So... In order to make the issue better understood i've took your first tutorial and just added a "SAVE" button to call saveToXML(Path p, VFlowModel flow) method, then adeded a button "load" to call loadFromXML(Path p).

Steps to reproduce:

1. Run the App class.
2. Save the flow by clicking save button.
3. Load the flow by clicking load button. (optional here close the nodes before).

Expected Result:
The flow is created.

Actual Result:
NullPointerException occurs.

Here is the code:

import java.io.IOException;
import java.nio.file.Paths;

import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.stage.Stage;
import eu.mihosoft.vrl.workflow.FlowFactory;
import eu.mihosoft.vrl.workflow.VFlow;
import eu.mihosoft.vrl.workflow.VNode;
import eu.mihosoft.vrl.workflow.fx.FXSkinFactory;
import eu.mihosoft.vrl.workflow.io.WorkflowIO;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.MouseEvent;
import jfxtras.labs.scene.layout.ScalableContentPane;

/**
*

• @author Michael Hoffer info@michaelhoffer.de
  */
  public class App extends Application {

  /**

  • The main() method is ignored in correctly deployed JavaFX application.
  • main() serves only as fallback in case the application can not be
  • launched through deployment artifacts, e.g., in IDEs with limited FX
  • support. NetBeans ignores main().
    *
  • @param args the command line arguments
    */
    public static void main(String[] args) {
    launch(args);
    }

  @OverRide
  public void start(Stage primaryStage) {

  // create scalable root pane
  ScalableContentPane canvas = new ScalableContentPane();
  
  // define background style
  canvas.setStyle("-fx-background-color: linear-gradient(to bottom, rgb(10,32,60), rgb(42,52,120));");
  
  // create a new flow object
  
  VFlow flow = FlowFactory.newFlow();
  
  // make it visible
  flow.setVisible(true);
  
  // add two nodes to the flow
  VNode n1 = flow.newNode();
  VNode n2 = flow.newNode();
  
  // specify input & output capabilities...
  
  // ... for node 1
  n1.addInput("data");
  n1.addOutput("data");
  
  // ... for node 2
  n2.addInput("data");
  n2.addOutput("data");
  
  // create skin factory for flow visualization
  FXSkinFactory fXSkinFactory = new FXSkinFactory(canvas.getContentPane());
  
  // generate the ui for the flow
  flow.setSkinFactories(fXSkinFactory);
  
  // added a button in order to save the flow 
  Button save = new Button();
  save.setText("save");
  save.setLayoutX(100);
  save.setLayoutY(100);
  
  // setting mouse action to save the flow
  save.setOnMouseClicked(new EventHandler<MouseEvent>() {
  
      @Override
      public void handle(MouseEvent event) {
          try {
              WorkflowIO.saveToXML(Paths.get("D://flow-01.xml"), flow.getModel());
          } catch (IOException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
          }
      }
  });
  
  // added load button in order to load the flow
  Button load = new Button();
  load.setText("load");
  load.setLayoutX(100);
  load.setLayoutY(200);
  
  // setting mouse action to load the flow
  load.setOnMouseClicked(new EventHandler<MouseEvent>() {
  
      @Override
      public void handle(MouseEvent event) {
          try {
              VFlow flow = WorkflowIO.loadFromXML(Paths.get("D://flow-01.xml"));
          } catch (IOException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
          }
      }
  });
  
  //adding the buttons
  canvas.getChildren().addAll(save, load);
  
  // the usual application setup
  Scene scene = new Scene(canvas, 800, 800);
  primaryStage.setTitle("VWorkflows Tutorial 01");
  primaryStage.setScene(scene);
  primaryStage.show();
  

  }
  }

I've also tried to load the flow direct from the xml from the beginning(loading the flow direct from the xml ), the same issue occurs

So i'm getting a NullPointerException

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at eu.mihosoft.vrl.workflow.io.WorkflowIO.toValueObject(WorkflowIO.java:389)
at eu.mihosoft.vrl.workflow.io.WorkflowIO.createFlowFromPersistent(WorkflowIO.java:273)
at eu.mihosoft.vrl.workflow.io.WorkflowIO.flowFromPersistentFlow(WorkflowIO.java:250)
at eu.mihosoft.vrl.workflow.io.WorkflowIO.loadFromXML(WorkflowIO.java:115)
at eu.mihosoft.vrl.workflow.io.WorkflowIO.loadFromXML(WorkflowIO.java:72)
at aa.bc.App$2.handle(App.java:105)
at aa.bc.App$2.handle(App.java:1)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.Scene$ClickGenerator.postProcess(Unknown Source)
at javafx.scene.Scene$ClickGenerator.access$8300(Unknown Source)
at javafx.scene.Scene$MouseHandler.process(Unknown Source)
at javafx.scene.Scene$MouseHandler.access$1800(Unknown Source)
at javafx.scene.Scene.impl_processMouseEvent(Unknown Source)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
at com.sun.glass.ui.View.notifyMouse(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(Unknown Source)
at com.sun.glass.ui.win.WinApplication$4$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

(WorkflowIO.java:389) goes here (witch has the TODO that i was talking about)

public static ValueObject toValueObject(VNode node, PersistentValueObject vObj) {
ValueObject result = new DefaultValueObject();

    result.setParent(node);
    // line 389
    result.setValue(vObj.getValue());
    // resulult. // .. TODO visualizationRequest isnot persistent! 11.01.2014

    return result;
}

If there is more information about this issue please do tell and thank you once again for the assistance.

Regards,
Lawrence.

[LaurentiuVasile]

Hello Michael,

     Any updates on this issue ?

Regards,
Lawrence.