By studying associations in UML (aggregation and composition) I realized that the difference between them would be only the existence or not of the parts without the whole.
- Aggregation = > Parts exist without the whole
- Composition = > Parts do not exist without the whole
Both deal with rules in the Part object, but I did not find anything that denoted rules in the whole object, eg
A request (Todo) consists of items (Part), there are no items without the whole (composition), the question is that a request also does not exist without items, how to represent this rule in the UML? that is, where I say that the whole object also does not exist without the Part object?