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Problem in navigating references [message #1753306]

Fri, 03 February 2017 11:00

Eclipse User

The figure below is part of my meta-model. If I should not change the meta-model,

https://www.eclipse.org/forums/index.php?t=getfile&id=28333&

1. How can I reach "D" from "B"?
2. How can I reach "targets" from "source"?
3. How can I navigate from "C" to "A"?

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[Updated on: Fri, 03 February 2017 11:05] by Moderator

Re: Problem in navigating references [message #1753315 is a reply to message #1753306]

Fri, 03 February 2017 12:47

Eclipse User

Hi

1: aB.A[source].body
2: aB.A[source].target
3: aC.oclAsType(A)

.A is an implicit opposite, which in your case is ambiguous. Not many tools support the [source] disambiguation.

Your metamodel looks very smelly with two A containments of B. I hope their multiplicity is [0..1]. Since there is then alternate containment,you may need to use the non-null .A[source] or .A[target]. Or .oclContainer().oclAsType(A).

Regards

Ed Willink

Re: Problem in navigating references [message #1753317 is a reply to message #1753315]

Fri, 03 February 2017 13:20

Eclipse User

Many thanks for your kind help.
Ed Willink wrote on Fri, 03 February 2017 17:47

.A is an implicit opposite, which in your case is ambiguous. Not many tools support the [source] disambiguation.

That means if I use it in my ATL transformation code, it doesn't work correctly?
What should I do?
Ed Willink wrote on Fri, 03 February 2017 17:47

Your metamodel looks very smelly with two A containments of B. I hope their multiplicity is [0..1]. Since there is then alternate containment,you may need to use the non-null .A[source] or .A[target]. Or .oclContainer().oclAsType(A).

The multiplicity of source is "1..1" and target is "1..*"
Does expressions need any change?

This is the part of a language meta-model that I change the class name for simplicity. In fact, "A" is "TransformationRule" and "B" is "FormalParameterExpression" (in-pattern and out-pattern of transformation).

Re: Problem in navigating references [message #1753322 is a reply to message #1753317]

Fri, 03 February 2017 15:05

Eclipse User

Hi

In ATL you can probably do .eContainer().oclAsType(A). Otherwise report a bug.

I am questioning the multiplicities at the container end.

Regards

Ed Willink

Re: Problem in navigating references [message #1753324 is a reply to message #1753322]

Fri, 03 February 2017 15:38

Eclipse User

Thank you very much.
Ed Willink wrote on Fri, 03 February 2017 20:05

In ATL you can probably do .eContainer().oclAsType(A). Otherwise report a bug.

That means, in ATL, my answers are:

1. B.eContainer().oclAsType(A).body
2. B.eContainer().oclAsType(A).target

?
Ed Willink wrote on Fri, 03 February 2017 20:05

I am questioning the multiplicities at the container end.

Yes, In action that multiplicity is 1 But not specify in the meta-model.

[Updated on: Fri, 03 February 2017 15:42] by Moderator

Re: Problem in navigating references [message #1753329 is a reply to message #1753324]

Fri, 03 February 2017 17:22

Eclipse User

Hi

No. It cannot be [1..1]. If it was there would be a double container which is illegal in Ecore (and UML).

Regards

Ed Willink

Re: Problem in navigating references [message #1753351 is a reply to message #1753329]

Sat, 04 February 2017 05:42

Eclipse User

Yes, I think I made a mistake about its multiplicity.

I have another question about this figure, if I have a class "E" which is inherited from "A", and I want to navigate from "C" to "E",

1. I should write aC.oclAsType(E) or aC.oclAsType(A).oclAsType(E)?
2. In ATL I should write "C" or "aC"?

[Updated on: Sat, 04 February 2017 05:44] by Moderator

Re: Problem in navigating references [message #1753352 is a reply to message #1753351]

Sat, 04 February 2017 06:27

Eclipse User

1 oclAsType() is just like a cast in Java, cast to what you want.
2 Without an example I cannot comment on whether you write C or aC. I informally use C as the type, aC as an instance,

Regards

Ed Willink

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