Defining Block Flow

Defining the block flow implies:

• Choosing the items (actions, blocks, or processes) that are executed within the block
• Defining the order and the conditions for their execution

The definition of the block flow strongly depends on the block type, that is, whether it is marked as Sequential, Parallel, Parallel Dynamic, Precondition or Postcondition Loop, or Alternatives.

Use this procedure to define the specific flow required for each block type.

1. Open the gallery, select a block, and open its design time.
2. To switch to edit mode, choose (Edit).
3. Select the appropriate object type that you want to add to the block flow from the Items dropdown box.
4. To insert an existing object, choose (Insert).
5. To create a new object, choose (Create New).
   • If you create a new block, you must define its flow as well, as described in this procedure.
   • If you create a new action, you must add callable objects to it.

     More information: Attaching Callable Objects

6. Repeat steps 3 to 5 to add more items.
7. Make sure that you follow the requirements for the relevant block type that you are creating as described in the table below:

   Block Type	Requirements
   Sequential	Any action or block can be added to the block flow. You must define the order in which the actions are to be executed. To move an item to the required position in the block flow, select it and choose (Move Up) or (Move Down). For actions with multiple result states, you can also define targets, as described in step 8 below.
   Parallel Parallel Dynamic	Any action or block can be added to the block flow. For actions with multiple result states, you can also define targets as described in step 8 below.
   Precondition Loop Postcondition Loop	You must add a loop decision action first. The decision action defines the loop condition. These block types require an action with two result states: Continue and Break. The result states are not displayed in the block flow because you cannot define targets for them. If you choose to add a second decision action, the new action replaces the one you previously inserted. For more information about decision actions, see Creating Decision Dialogs . You must add a loop body block. It includes the actions that are executed if the loop condition occurs. You can choose any block type.
   Alternatives	You must add a decision action first. It defines at least two different result states for which you can define targets as described in step 8. You can add any other actions, blocks, or processes, and can define them as targets for the result states of the decision action.

8. If an action in the block flow defines multiple result states, you can configure a target for each individual result state. The target is an action that is executed if the relevant result state is reached.

   To configure a target, select the relevant result state and choose the required action from the dropdown box in the Target column. You can select an action located in:

   • The same block

     Choose from the actions that are listed in the dropdown box.

   • A different block

     From the dropdown box, select Other… and choose the relevant name of the action.

     When configuring targets for result states that are in different blocks, you have to make sure they are in accordance with the relevant block types you are using. For example, if the target is in a sequential block, you can choose any action from the block as a target action. If, however, the target is in a precondition loop block, the target can only be the first action in the block, since it is the decision action that defines the loop condition.

     The following table shows whether a certain type of block can contain a source or target action:

     Action Flow / Block Type	Sequential	Precondition Loop	Postcondition Loop	Parallel & Parallel Dynamic	Alternatives (User Decisions)
     Source	Yes	No	No	No	Yes
     Target	Yes	Action 1	Yes	Action 1	Action 1

   The source block contains the decision action that requires result states. The target block contains the target of the result state. Action 1indicates a target in the respective block type can only be the first action in the block.

   If you select Terminal, at runtime the current block execution would end if the relevant result state is reached, and the next block in the process flow would be executed.

9. For parallel and parallel dynamic blocks, you can define more complex behavior and set criteria for block completion. On the Join Behavior tab page, you can choose one of the following options:
   • Default - block is completed when all actions in the block are completed.
   • Process Flow - block is completed when a specified number of actions are completed.

     You can set the limit for completed actions as a percentage or as the number of branches (steps).

     Tip

     If the block contains five actions and you want to make sure it completes as soon as any three of them are executed, you can specify a limit of 3 Branch(es) or 60 Percent.

   • Data Flow - block is completed when a particular condition is reached.

     To evaluate the condition, you can use a callable object for background execution, for example a Business Logic callable object which receives as input context parameters, makes a decision and returns result states.

     Choose a callable object and use Parameter Mapping to map the relevant block context parameters to the input parameters of the callable object.

     UseResultStateMapping to map the result states of the callable object to the two possible result states of the block:

     • WAITING - wait for the next action to be executed and re-evaluate condition
     • COMPLETED - skip all remaining actions and complete block execution
10. To save all changes, choose (Save All).