Attributes for the <control> Element

The <control> element has the following attributes:

• access – An optional attribute of type accessEnum, which specifies the accessibility of the control block. These are the possible values:

  • PUBLIC – Access is unrestricted, which is the default value.

  • PROTECTED – Access is limited to derived components and entities that are in the same path.

  • PATH – Access is limited to entities that are in the same path.

  • PRIVATE – Access is limited to this component.

  Only PUBLIC blocks can be run directly from the component.

• modifier – An optional attribute of type modifierEnum, which specifies the override requirements for the control block. These are the possible values:

  • ABSTRACT – The block cannot include a body. Instead, the body must be specified by nonabstract derived components. A control block can only be declared abstract if the component is also declared abstract. An abstract block cannot be private. Nonabstract blocks must declare a body.

  • FINAL – The control block cannot be overridden by derived components.

  If this attribute is omitted, derived components can choose whether to override the block.

• name – A required attribute of type entityName, which is the name of the control block. This is referenced from a <call> step to execute the control.

• description – An optional attribute that is a string that describes the control block.

• returns – An optional attribute that indicates that the block must return a value. Valid values are true or false. If returns=true is specified, then each execution step within the block must end with either a <return> step or an uncaught <raise> step. The default is false.