Using the Flow Element

Use the Flow element to define a set of activities that will execute concurrently (in parallel).

The Flow activity is a structured activity, containing other activities separated into individual control paths or branches. You can embed as many paths in the activity as you want, and they will all be executed simultaneously.

During execution, each path is executed concurrently, and the activities on each are executed in the order in which they appear, unless they are the source of a link. When the activities are the source of a link, the condition of the link and the join condition of the activity must be evaluated. If the link conditions that lead to an activity conflict with those of its join condition, then a fault is thrown on that activity.

Usage

In the Design view, drag the Flow Element from the Palette to the diagram.

Drag an element to the placeholder inside the Flow element. If you add another element into the same branch of the Flow element, the elements within a branch are automatically wrapped in the Sequence element.

Adding Branches to the Flow Element

You can add one or more branches to the Flow element. The Flow element has a special user interaction style. It always shows a placeholder for the next branch that you might wish to add. To add a new branch, drag an element from the Palette to the immediately available "next branch" placeholder.

Changing the Order of Elements inside Flow

To change the order of activities inside the Flow element:

1. In the Design view, right-click the Flow element and select Change Order.

2. Select an element and use the Move up or Move down buttons to change the position of the element inside the container.