In activity diagrams, an object node is an abstract activity node that helps to define the object flow in an activity. An object node indicates that an instance of a classifier might be available at a particular point in the activity.
The following table describes the types of object nodes that you can use to model object flow in activity diagrams.
Object node type | Description | Icon |
---|---|---|
Activity parameter | This node specifies the input and output parameters for the activity. | ![]() |
Central buffer | This node is used to consolidate data from several sources and destinations. Central buffer nodes do not connect directly to actions. | ![]() |
Data store | This node is used to model data flow in which the data is persistent. | ![]() |
Input pin | This node represents the input parameters on an action. The input pin holds the input values that are received from other actions. | ![]() |
Output pin | This node represents the output parameters on an action. The output pin holds the output values that an action produces. Object flow edges deliver the output values to other actions. | ![]() |