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Bug 312598

Summary:	[Use case editor] Why does "subject" default to being a component?
Product:	[Modeling] Papyrus	Reporter:	Bran Selic <selic>
Component:	Core	Assignee:	Patrick Tessier <Patrick.Tessier>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	P3	CC:	sebastien.gerard
Version:	unspecified
Target Milestone:	---
Hardware:	PC
OS:	Windows XP
Whiteboard:

Description Bran Selic

2010-05-12 08:18:06 EDT

The palette item for the subject assumes that the subject is a kind of Component, which is a very specialized type of classifier (in fact, in my view, Components are not particularly useful in UML, since structured classes pretty much cover everything components can represent and more.) If a default subject has to be included it should be a class, not a component (remember, a structured class can also contain an internal structure, ports, connectors, etc.). However, it should be possible to select from a number of different classifier types (actors, classes, components, etc.) When I tried to create a custom palette for use cases, for some reason I could not include Class, since it was not available for inclusion in the palette. Strange.

Comment 1 Yann Tanguy

2010-11-09 09:10:03 EST

(In reply to comment #0)
> The palette item for the subject assumes that the subject is a kind of
> Component, which is a very specialized type of classifier (in fact, in my view,
> Components are not particularly useful in UML, since structured classes pretty
> much cover everything components can represent and more.) If a default subject
> has to be included it should be a class, not a component (remember, a structured
> class can also contain an internal structure, ports, connectors, etc.). However,
> it should be possible to select from a number of different classifier types
> (actors, classes, components, etc.) When I tried to create a custom palette for
> use cases, for some reason I could not include Class, since it was not available
> for inclusion in the palette. Strange.

Right, the tool should not make such choices.
Also there is a confusion between "subject" and "containment" relationship here. In the UseCase diagram, it should be possible to show a UseCase in any of its subject. 
Currently the UseCase can only be dropped in its container (which may be the subject or not).

Comment 2 Emilien Perico

2010-11-09 09:57:16 EST

this bug is linked to this one:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=281977

Comment 3 Patrick Tessier

2012-04-11 08:32:45 EDT

for the moment class component and Interface can be subject of the Usecase diagram

Comment 4 Patrick Tessier

2012-04-16 04:59:07 EDT

subject can be also StateMAchine and Datatype.
see revision 7881