Creating Blocks

You can create blocks using the GP design time API. The interface allows you to manipulate with block types and structure.

You have instantiated the IGPDesigntimeUpdateManager . For more information, see Instantiating the Design Time Manager .

1. Create a block by providing its basic data:

You need to specify a category for the newly-created block. For this purpose, you can create a new category or provide the Id of an existing one.

importjava.util.Locale;

importcom.sap.caf.eu.gp.context.api.IGPUserContext;

importcom.sap.caf.eu.gp.process.api.IGPCategory;

importcom.sap.caf.eu.gp.process.api.IGPModifiableBlock;

importcom.sap.caf.eu.gp.process.api.GPProcessFactory;

importcom.sap.caf.eu.gp.process.dt.api.IGPDesigntimeManager;

importcom.sap.caf.eu.gp.process.dt.api.IGPDesigntimeUpdateManager;

importcom.sap.caf.eu.gp.process.api.GPBlockType;

// instantiate the design time manager to get the root category

IGPDesigntimeManagerdtManager = GPProcessFactory.getDesigntimeManager();

IGPCategoryroot = dtManager.getRootCategory(userContext);

// create a new category "test" in the root category

IGPCategory cat = manager.createCategory("test","A test category", root);

// create a block in the cat category

StringbName = "Block";

StringbDescription = "A test block";

IGPModifiableBlockb = manager.createBlock(

         GPBlockType.BLOCK_TYPE_SEQUENTIAL,

         Locale.getDefault(),

         bName,

         bDescription,

         cat.getID()

);

The example above implements a sequential block type. Currently, the GP API supports the following block types:

• BLOCK_TYPE_SEQUENTIAL
• BLOCK_TYPE_PARALLEL

For more information on block types, see Creating Blocks in Modeling and Configuring Workflows.

1. Add content to the block.

   The block content is represented by a block structure ( IGPModifiableBlockStructure ). It is an indexed sequence of items ( IGPModifiableBlockStructureItem ), which hold object references to activities within the block.

   Note

   Block structure items also hold information about parameter mappings, transitions between activities, exception handling and role information.

   The GP design time API provides the following functionalities for block structure manipulation:

   • Adding an item to the structure

     We define a block b with three actions: a_0 , a_1 , a_2 .

     importcom.sap.caf.eu.gp.process.api.IGPModifiableAction;   IGPModifiableBlockb = null;   try{    // create the block and the actions    ...   // add the actions to the structure    b.getModifiableStructure().addItem(a_0);    b.getModifiableStructure().addItem(a_1);    b.getModifiableStructure().addItem(a_2);      // save the block object    manager.save(b);    } finally {        if (b != null) {           // release the block object           manager.release(b);        }    }

   For more information on how to implement actions, see Creating Actions .

   • Inserting an item into a specific position in the structure

     Suppose you have already created and saved block b, and for some reason you decide that you need to execute another activity before action a_1 , a block named b_0 for example. You insert the block into the structure on position 2. Thus, action a_1 is shifted to position 3.

     b.getModifiableStructure().insertItem(2,b_0);

   • Replacing an item in the structure
     To replace the item on position 3 (in our case,

     a_1b_0

     ) with , write:

     b.getModifiableStructure().setItem(3, b_0);

   • Exchanging two items in the structure
     To swap items on positions 3 and 4 (in our case,

     b_0a_2

     and ), write:

     b.getModifiableStructure().swap(3, 4);

• Deleting an item from the structure

  To delete the item on position 1 (a _0 ), write:

  b.getModifiableStructure().removeItem(1);

1. Make sure you save and release the block after you have created and modified it.

   manager.save(b); manager.release(b);

Once you have assigned actions to the block, you can also:

• Map local, input and output parameters

  See Implementing Parameter Mapping .

• Set targets for the result states of the callable objects

  See Defining Transitions .

• Implement exception handlers

  See Implementing Exception Handling .

For more information about block editing, see Editing GP Development Objects .