Create Data Flow Diagram Using Open API

A Data Flow Diagram displays the flow of data of a system, using rectangles and arrows. This article will demonstrate how to create a data flow diagram using Open API.

The diagram will be created by the plugin

Create Blank Data Flow Diagram

First we use DiagramManager.createDiagram to create a blank diagram.

//Create Blank DFD
DiagramManager diagrammanager = ApplicationManager.instance().getDiagramManager();
IDiagramUIModel dfd = (IDiagramUIModel) diagrammanager.createDiagram(IDiagramTypeConstants.DIAGRAM_TYPE_DATA_FLOW_DIAGRAM);
dfd.setName("Simple Data Flow Diagram");

Create Processes, Entities and Data Stores

A process, entity and data store can all be created once the diagram is created. We can use IModelElementFactory to create processes, external entities and data stores.
This is how you create a process:

//Create Order Food Process
IDFProcess orderFood = IModelElementFactory.instance().createDFProcess();
orderFood.setName("Order Food");
orderFood.setDfId("0.1");
//Create the process shape on diagram
IDFProcessUIModel shapeOrderFood = (IDFProcessUIModel) diagrammanager.createDiagramElement(dfd, orderFood);
shapeOrderFood.setBounds(450, 395, 100, 60);

This is how you create an external entity:

//Create External Entity
IDFExternalEntity customer = IModelElementFactory.instance().createDFExternalEntity();
customer.setName("Customer");
//Create the external entity on diagram
IDFExternalEntityUIModel shapeCustomer = (IDFExternalEntityUIModel) diagrammanager.createDiagramElement(dfd, customer);
shapeCustomer.setBounds(450, 200, 100, 50);

This is how you create a data store:

//Create Data Store
IDFDataStore inventory = IModelElementFactory.instance().createDFDataStore();
inventory.setName("inventory");
//Create data store on diagram
IDFDataStoreUIModel shapeInventory = (IDFDataStoreUIModel) diagrammanager.createDiagramElement(dfd, inventory);
shapeInventory.setBounds(200, 400, 100, 50);

You can try repeating these steps to create more processes, external entities and data stores.

Create Data Flows

The way to create a data flow is similar to a process, entity and data store. However, rather than using the DiagramManager.createDiagramElement() method, DiagramManager.createConnector() is being used instead.
In order the name to the flow be seen, the method IDFDataFlowUIModel.resetCaption() has to be used.

First set up the model for the data flow:

//Create Data Flow
IDFDataFlow customerOrderFood = IModelElementFactory.instance().createDFDataFlow(); 
customerOrderFood.setName("Order");
 //The data flow is connecting from the customer external entity... 
customerOrderFood.setFrom(customer); 
//...to the order food process 
customerOrderFood.setTo(orderFood);

Then create the shape on the diagram, do not forget resetting the caption:

//Create the data flow on diagram
//If new Point[] is empty, the data flow will be created automatically 
IDFDataFlowUIModel shapeCustomerOrderFood = (IDFDataFlowUIModel) diagrammanager.createConnector(dfd, customerOrderFood, shapeCustomer, shapeOrderFood, new Point[] {new Point(480,250), new Point(480,395)});
shapeCustomerOrderFood.resetCaption();

Now try  to create other data flows by repeating these steps.

Show Up the Diagram

Finally, show up the diagram.

// Show up the diagram
diagrammanager.openDiagram(dfd);

Sample Plugin

The sample plugin demonstrate how to create data flow 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.

Download the Plugin

You can click this link to download the sample plugin.