UML syntax: Operations

[ronaldtse]

Operations

• Def.- An operation is a behavioral feature of a classifier, which specifies name, type, parameters and contraints for the call of the behavior.
• In addition to the features and operation inherits from BehavioralFeature, the operation can:
  • Have preconditions and postconditions and a body condition.
  • Specify whether it will change the state of the pertaining instance (see isQuery).
  • Have a type.

Notation and Semantics

• Although the syntax of operations is described somewhat imprecisely in the UML specification, the notation should look like this: [visibility]name(parameter list) [:type][{property string}]

Operation Property

• {query} can be used to specify a property value for the operation.
• This characterizes an operation that has no side effects, that is, an operation that does not change the state of the object and other objects such as get() operations

Pre-Post-Body conditions

• The precondition must always be true before the operation is executed.
• The postconditions have to be true after the exection.
• The body condition has to be true during the execution.
• If an exception occurs during operation execution, the postconditions must not be true.

Difference between body condition and postcondition

• The difference between body condition and postcondition is that the invariant (of the body condition) can be overwritten (redefined) by inheritance.
• A postcondition merely lets you add postconditions. The latter is also true for a precondition.

Examples

• getPosition(return x:int, return y:int)
• Enlarge(byFactor:Real):GeomFigure
• +addPhone(phone:String)
• #release():contractStatus

[w00lf]

Operations

• Def.- An operation is a behavioral feature of a classifier, which specifies name, type, parameters and contraints for the call of the behavior.

• In addition to the features and operation inherits from BehavioralFeature, the operation can:

  • Have preconditions and postconditions and a body condition.
  • Specify whether it will change the state of the pertaining instance (see isQuery).
  • Have a type.

Notation and Semantics

• Although the syntax of operations is described somewhat imprecisely in the UML specification, the notation should look like this: [visibility]name(parameter list) [:type][{property string}]

Operation Property

• {query} can be used to specify a property value for the operation.
• This characterizes an operation that has no side effects, that is, an operation that does not change the state of the object and other objects such as get() operations

Pre-Post-Body conditions

• The precondition must always be true before the operation is executed.
• The postconditions have to be true after the exection.
• The body condition has to be true during the execution.
• If an exception occurs during operation execution, the postconditions must not be true.

Difference between body condition and postcondition

• The difference between body condition and postcondition is that the invariant (of the body condition) can be overwritten (redefined) by inheritance.
• A postcondition merely lets you add postconditions. The latter is also true for a precondition.

Examples

• getPosition(return x:int, return y:int)
• Enlarge(byFactor:Real):GeomFigure
• +addPhone(phone:String)
• #release():contractStatus

@ronaldtse duplicate of #20 ?

[ronaldtse]

Operations

• Def.- An operation is a behavioral feature of a classifier, which specifies name, type, parameters and contraints for the call of the behavior.

• In addition to the features and operation inherits from BehavioralFeature, the operation can:

  • Have preconditions and postconditions and a body condition.
  • Specify whether it will change the state of the pertaining instance (see isQuery).
  • Have a type.

This is the difference. An operation is a feature of the classifier (e.g. Class). It extends from feature by:

1. it allows conditions pre/post/during
2. it allows specifying whether it is a Query or not (Query means doesn't change data)
3. Have a type.