Create Activity Diagram using Open API

Activity diagram is one of the behavior diagram in Unified Modeling Language (UML) which used to model the flow of control of your system. With the support of model of decision, activity diagram provide graphical representation to present the step-by-step flow of control of your system. Instead of manually create the activity diagram, you can also generate it via Visual Paradigm’s Open API. In this article we will show you how to create activity diagram with Open API.

Activity Diagram which we going to create via Open API

This is the activity diagram we are going to create. It consist of 1 activity, 7 action node, one initial and one final node, fork & join node, decision and merge node, object node as well as control flows and object flows.

Create Blank Activity Diagram

Let’s start by create a blank diagram. We can use DiagramManager.createDiagram operation to create a blank new diagram.

// create blank activity diagram
DiagramManager diagramManager = ApplicationManager.instance().getDiagramManager();
IActivityDiagramUIModel diagram = (IActivityDiagramUIModel) diagramManager.createDiagram(IDiagramTypeConstants.DIAGRAM_TYPE_ACTIVITY_DIAGRAM);

Create the base Activity and Activity Parameter Node

When the diagram is ready we can start to create the elements in the diagram. We first create the Activity.

// create Process Order activity model
IActivity activityProcessOrder = IModelElementFactory.instance().createActivity();
// specify the name of the activity model
activityProcessOrder.setName("Process Order");
// specify the pre-condition & post-condition
activityProcessOrder.setPrecondition("Order complete");
activityProcessOrder.setPostcondition("Order closed");
// set the activity as single execution
activityProcessOrder.setSingleExecution(true);
// create view for Process Order activity
IActivityUIModel activityProcessOrderShape = (IActivityUIModel) diagramManager.createDiagramElement(diagram, activityProcessOrder);
// specify its size and position
activityProcessOrderShape.setBounds(173, 82, 790, 391);
// set the caption placement to top left
activityProcessOrderShape.setModelElementNameAlignment(IShapeUIModel.MODEL_ELEMENT_NAME_ALIGNMENT_ALIGN_TOP_LEFT);
// set to automatic calculate the initial caption position
activityProcessOrderShape.setRequestResetCaption(true);

Create Process Order activity

After we create the activity we then create the parameter node on the activity.

// create Requested Order activity parameter node
IActivityParameterNode paramRequestedOrder = IModelElementFactory.instance().createActivityParameterNode();
paramRequestedOrder.setName("Requested Order");
// add the parameter node to Process Order activity
activityProcessOrder.addActivityParameterNode(paramRequestedOrder);
// create view for Requested Order activity parameter node
IActivityParameterNodeUIModel paramRequestedOrderShape = (IActivityParameterNodeUIModel) diagramManager.createDiagramElement(diagram, paramRequestedOrder);
paramRequestedOrderShape.setBounds(126, 198, 95, 30);
// add the view of Requested Order to Process Order
activityProcessOrderShape.addChild(paramRequestedOrderShape);
paramRequestedOrderShape.setRequestResetCaption(true);

Create parameter on Process Order activity

Create Initial and Final Node

Next we create the initial and final node in the activity.

// create initial node & its view
IInitialNode initialNode = IModelElementFactory.instance().createInitialNode();
activityProcessOrder.addChild(initialNode);
IInitialNodeUIModel initialNodeShape = (IInitialNodeUIModel) diagramManager.createDiagramElement(diagram, initialNode);
initialNodeShape.setBounds(265, 148, 20, 20);
activityProcessOrderShape.addChild(initialNodeShape);
// create final node & its view
IActivityFinalNode finalNode = IModelElementFactory.instance().createActivityFinalNode();
IActivityFinalUIModel finalNodeShape = (IActivityFinalUIModel) diagramManager.createDiagramElement(diagram, finalNode);
finalNodeShape.setBounds(885, 267, 20, 20);
activityProcessOrderShape.addChild(finalNodeShape);

Create initial and final node

Create Actions

Now we move on to create the actions.

// create Receive Order action & its view
IActivityAction actionReceiveOrder = IModelElementFactory.instance().createActivityAction();
actionReceiveOrder.setName("Receive Order");
activityProcessOrder.addChild(actionReceiveOrder);
IActivityActionUIModel actionReceiveOrderShape = (IActivityActionUIModel) diagramManager.createDiagramElement(diagram, actionReceiveOrder);
actionReceiveOrderShape.setBounds(255, 195, 60, 40);
actionReceiveOrderShape.setRequestResetCaption(true);
activityProcessOrderShape.addChild(actionReceiveOrderShape);

Now it’s your turn to create the other actions.

Create actions

Create Decision and Merge Node

Next we create the decision and merge node.

// create decision node & its view
IDecisionNode decision = IModelElementFactory.instance().createDecisionNode();
IDecisionNodeUIModel decisionShape = (IDecisionNodeUIModel) diagramManager.createDiagramElement(diagram, decision);
decisionShape.setBounds(373, 195, 20, 40);
activityProcessOrderShape.addChild(decisionShape);
// create merge node & its view
IMergeNode merge = IModelElementFactory.instance().createMergeNode();
IMergeNodeUIModel mergeShape = (IMergeNodeUIModel) diagramManager.createDiagramElement(diagram, merge);
mergeShape.setBounds(809, 195, 20, 40);
activityProcessOrderShape.addChild(mergeShape);

Create decision and merge node

Create Fork and Join Node

After create the decision and merge node, we then create the fork and join node.

// create fork node & its view
IForkNode fork = IModelElementFactory.instance().createForkNode();
IForkNodeUIModel forkShape = (IForkNodeUIModel) diagramManager.createDiagramElement(diagram, fork);
forkShape.setBounds(574, 185, 12, 60);
activityProcessOrderShape.addChild(forkShape);
// create join node & its view
IJoinNode join = IModelElementFactory.instance().createJoinNode();
IJoinNodeUIModel joinShape = (IJoinNodeUIModel) diagramManager.createDiagramElement(diagram, join);
joinShape.setBounds(756, 185, 12, 60);
activityProcessOrderShape.addChild(joinShape);

Create fork and join node

Create Object Node

The last node we need to create is the object node. To create object node:

// create object node & its view
IObjectNode objectNode = IModelElementFactory.instance().createObjectNode();
objectNode.setName("Invoice");
activityProcessOrder.addChild(objectNode);
IObjectNodeUIModel objectNodeShape = (IObjectNodeUIModel) diagramManager.createDiagramElement(diagram, objectNode);
objectNodeShape.setBounds(333, 407, 80, 40);
objectNodeShape.setRequestResetCaption(true);
activityProcessOrderShape.addChild(objectNodeShape);

Create object node

Create Control Flow and Object Flow

Once all the nodes are created we then move to create the connectors. There are 2 kind of connectors used in our diagram, the control flow between actions, initial node and final node, as well as the object flow between actions and object node, as well as parameter node. We start by create control flow between decision and Fill Order action.

// create control flow from decision to Fill Order
IControlFlow flowDecisionFillOrder = IModelElementFactory.instance().createControlFlow();
flowDecisionFillOrder.setFrom(decision);
flowDecisionFillOrder.setTo(actionFillOrder);
// specify guard condition for control flow
flowDecisionFillOrder.setGuard("order accepted");
IControlFlowUIModel flowDecisionFillOrderShape = (IControlFlowUIModel) diagramManager.createConnector(diagram, flowDecisionFillOrder, decisionShape, actionFillOrderShape, null);
// specify the size and bounds of the control flow caption
flowDecisionFillOrderShape.getCaptionUIModel().setBounds(380, 220, 100, 20);

Next we go to create to object flow between parameter node and Receive Order action.

// create object flow from Requested Order to Receive Order
IActivityObjectFlow flowRequestedOrderReceivedOrder = IModelElementFactory.instance().createActivityObjectFlow();
// specify the from & to end
flowRequestedOrderReceivedOrder.setFrom(paramRequestedOrder);
flowRequestedOrderReceivedOrder.setTo(actionReceiveOrder);
// create connector into diagram
diagramManager.createConnector(diagram, flowRequestedOrderReceivedOrder, paramRequestedOrderShape, actionReceiveOrderShape, new Point[] {new Point(221, 215), new Point(255, 215)});

Again, it’s your turn to create the other connectors in the diagram.

Create control and object flows

Show up the diagram

When everything is ready we can show up the diagram.

// show up the diagram
diagramManager.openDiagram(diagram);

Sample Plugin

The sample plugin attached in this article demonstrate how to create activity diagram using Open API. After you deploy the plugin into Visual Paradigm you can then click the plugin button in the application toolbar to trigger it.

Trigger sample plugin

Download Sample Plugin

You can click this link to download the sample plugin.