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oclIsUndefined and empty String [message #498536]

Tue, 17 November 2009 06:49

Eclipse User

Originally posted by: formatzeh.gmx.de

I have some ocl constraints in my EMF meta-model which should evaluated
at runtime. One of my classes has two attributes (category and url) of
type String where only one of both must be set (xor). Therefor I defined
the following constraint:

(self.url.oclIsUndefined() and (not
self.classificationCategory.oclIsUndefined())) or ((not
self.url.oclIsUndefined()) and self.classificationCategory.oclIsUndefined())

The first time I create a model with the EMF-generated editor I only set
url and the constraint wasn't violated. Then I set the category as well
and the violation was indicated correctly. After that I removed the
category again by deleting the String in the properties view. But
surprisingly the message popped up that the constraint still is
violated. Then I saw in the source of the model that category had the
empty string category="" after deleting it. After removing it by hand
from the source the evaluation was successful again. So if category has
the empty string oclIsUndefined doesn't return true - well that's ok but
not in my case. So can you help me with the correct XOR expression
respecting the empty string as well?

Re: oclIsUndefined and empty String [message #498548 is a reply to message #498536]

Tue, 17 November 2009 07:50

Eclipse User

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Hi Gilbert,

note that "xor" exists in ocl :

(self.url.oclIsUndefined() or self.url = '') xor
(self.classificationCategory.oclIsUndefined() or
self.classificationCategory = '')

should do the trick

Laurent

Gilbert Mirenque wrote:
> I have some ocl constraints in my EMF meta-model which should evaluated
> at runtime. One of my classes has two attributes (category and url) of
> type String where only one of both must be set (xor). Therefor I defined
> the following constraint:
>
> (self.url.oclIsUndefined() and (not
> self.classificationCategory.oclIsUndefined())) or ((not
> self.url.oclIsUndefined()) and self.classificationCategory.oclIsUndefined())
>
> The first time I create a model with the EMF-generated editor I only set
> url and the constraint wasn't violated. Then I set the category as well
> and the violation was indicated correctly. After that I removed the
> category again by deleting the String in the properties view. But
> surprisingly the message popped up that the constraint still is
> violated. Then I saw in the source of the model that category had the
> empty string category="" after deleting it. After removing it by hand
> from the source the evaluation was successful again. So if category has
> the empty string oclIsUndefined doesn't return true - well that's ok but
> not in my case. So can you help me with the correct XOR expression
> respecting the empty string as well?

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Re: oclIsUndefined and empty String [message #498557 is a reply to message #498548]

Tue, 17 November 2009 08:45

Eclipse User

Originally posted by: formatzeh.gmx.de

Oh...thanks Laurent

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